You may email support inquiries to us at the follow address: support email

Should you need to call us, our support hours are 8 AM - 5 PM MST. Our technical support staff can be reached at 720-891-0030.

Please fill out this form to get more information.


For photopia, our technical support is intended to answer any questions you may have about the use of the software.

Technical support is only avaliable if you have an active Annual Maintenance contract.

If your Annual Maintenance contract is expired, you can use these online resources. If you need assistance beyond these, you may renew your Annual Maintenance contract.

It is beyond the scope of standard technical support to assist you in creating optics or teaching you SOLIDWORKS or Rhino.

We offer training if you need a quick start, more detailed help, or assistance with a specific project.

Photopia for Rhino installs as an plug-in to Rhino 6 or Rhino 7.

Photopia for Solidworks installs as an add-in to SOLIDWORKS 2018-2021.

Requirements

SOLIDWORKS

Requirements

  • SOLIDWORKS 2018 - 2021
  • Windows 8.1 or 10
  • 64-bit Intel or AMD process (not ARM)
  • 16GB RAM
  • 2 GB disk space
  • Internet access

Not Supported

  • Windows 8 or older
  • Windows Server (any version)
  • ARM Processors
  • 32-bit processors
Rhino

Requirements

  • Rhino 6 or Rhino 7
  • Windows 8.1 or 10
  • 64-bit Intel or AMD processor (not ARM)
  • 16GB RAM
  • 2 GB disk space
  • No more than 63 CPU cores
  • Internet access

Not Supported

  • Windows 8 or older
  • Windows Server (any version)
  • ARM Processors
  • 32-bit processors

Recommendations

CPU

Photopia performs all raytracing calculations on your CPU and these calculations are multi-threaded. Therefore, a faster CPU with more cores will result in faster raytraces.

Photopia can use an unlimited number of cores, however all of those cores must be on the same NUMA Node. Raytraces cannot be split between NUMA Nodes (processors) at this time.

A processor's Boost speed is typically the speed the raytracer will use if allowed based on power management and thermal considerations.

Graphics

Photopia does not perform any raytracing calcuations on the graphics card.

A better graphics card will likely improve other aspects of your CAD system.

Disks / Storage

During the raytrace Photopia will write out results files and read library data from disk. For this reason, fast disk access will result in some speed improvements.

The best option is a local SSD, followed by a local HDD, followed by network storage (sometimes unreliable for SW).

Install and Setup

Mac OS

The core Photopia raytrace only runs in Windows.

Although Rhino has a Mac OS native version, to use Photopia for Rhino you will have to use Rhino inside of Windows.

The best option for running Solidworks or Rhino on Mac OS is to dual boot using BootCamp (unless you have an M1 Mac, in which BootCamp isn't yet possible.

Using a virtual machine solution, like VMWare Fusion, Parallels, or VirtualBox isn't officially supported by Solidworks or Rhino, and so it may have some hiccups or performance impacts. However, we do have customers using these solutions that are happy with their performance.

Another option you have is to Remote Desktop or VNC into a Windows machine, either located in your office or hosted on a provider like AWS or Azure.

PDM/Vault SetupSOLIDWORKS Only

Photopia for SOLIDWORKS has several library files that are installed locally. This includes:

  • Lamp and Material data files in %programdata%\LTI Optics\Library\
  • Lamp Part files in %programdata%\LTI Optics\Library\Solidworks\Library\Lamps\
  • Appearance files in %programdata%\LTI Optics\Library\Solidworks\Library\Photopia Appearances\

In order to ensure that Photopia for SOLIDWORKS functions correctly, all of the files in the above folder must remain in place.

If you operate a PDM/Vault to store, version and share files among users, Photopia can work within this system.

You could create a shared Lamps folder that user's would pull from and copy our library to this folder, however this is not recommended for Photopia users. Since we do not have all lamps as Part files yet, the "Add Lamp" function in Photopia manages this and creates part files as necessary. If you were to just put the current Part files in a folder, your users would miss out on all of the other lamps in our library. Additionally, they would not be able to edit items like lumens, watts, and mating when adding, they would have to do that as a separate step.

Our recommendation is when your users check an assembly into the vault, they should also check-in the Lamp Model Part files that are being used in that assembly. These could be put in a Lamps directory if you wish, or just stored alongside the assembly. When another user checks out the assembly, they'll get a local copy of the lamp model in that checked out folder. For any users with Photopia installed, it will still run the raytrace properly since the data is included in the part file.

Once a lamp part is in an assembly, the name and location of the part file is not critical. User's may rename and/or move the part file anywhere they wish and the raytrace will still perform as long as they still have Photopia installed.

Beginning with Photopia 2020.1 released August 2020, Photopia uses an online licensing system, MyPhotopia.

my|photopia Users Guide
SOLIDWORKS

Analyses must be performed inside of Assembly files.

All project settings and raytrace results are stored inside of your Assembly file.

The orientation of the assembly model does not matter, Photopia for SOLIDWORKS has tools to set up the photometric test coordinates for your model.

All items are saved per configuration, allowing you to test multiple setups inside the same assembly model.

Rhino

All project settings and raytrace results are stored inside of your Rhino 3DM file.

The orientation of the model does not matter, Photopia for Rhino has tools to set up the photometric test coordinates for your model.

Rhino - Nested Blocks

IGES or STEP files exported from a solid modeler assembly file will contain multiple parts and sub-assemblies. All of the parts will be contained within nested blocks, all on a single layer when first imported into Rhino. To avoid the tedium of exploding multiple times and moving parts to layers you manually create, Photopia for Rhino includes a tool that does all of that automatically. The tool produces a new layer for each block based on the part names and maintains sub-assembly structures of the original assembly by using sub-layers. Turning off a layer in Rhino that contains sub-layers turns off all sub-layers in one click, just like turning off the display of a sub-assembly in a feature tree.

Usage:

  1. Import the IGES or STEP file into a new Rhino model.
  2. Run the ExplodeBlocksToLayers command.
  3. Type "L" at the first prompt to set the option for a new layer per block. The default option will put all parts onto a single layer.
  4. Then select the imported block and press enter.

Lamps are special versions of SOLIDWORKS parts or Rhino blocks that have all of LTI Optics' detailed lamp model data incorporated in them. This means that when you run a raytrace you're using the full detailed lamp model, even if the display geometry is simplified. You will have accurate far and near field distribution, as well as full color data for our new color lamps. Rhino displays the exact 3D lamp model data. In SOLIDWORKS, there are two basic types of lamps you'll encounter.

Types

Full Rhino

Rhino will show the full Photopa lamp geometry, including emission surfaces. This is the actual geometry that is sent to the raytracer, and thus is polygon based.

Full SOLIDWORKS

For new lamps and popular old lamps, we'll have a full SOLIDWORKS part that shows the geometry of the lamp. This geometry is just for illustration, we use much more detailed geometry during the raytrace.

Generic Placeholder Geometry

For older lamps we'll have a simple placeholder part so that you know where the lamp is, but you won't see detailed geometry. Don't worry, we still use the detailed geometry in the raytrace, we just don't have a SOLIDWORKS representation of it.

For these lamps, the Lamp center is set at the 0,0,0 point from Photopia, which is generally the Photometric Center or center of the luminous area of the lamp. This is typically:

  • Top center of the phosphor area for LEDs
  • Arc center for MH lamps
  • Center of tube for linear lamps

Adding A Lamp

SOLIDWORKS
  1. In your assembly model, choose Add Lamp from the Photopia tab or menu.
  2. Use the drop down to pick the lamp based on its short code, or use the Browse Lamps button to use a sortable browser.
  3. Solidworks Lamp Properties Page Solidworks Lamp Model Browser
  4. You may select a Coordinate System now to position the lamp, or use mates later to orient the lamp. The Coordinate System -Z will correspond to Photometric Nadir of the lamp, and +Y corresponds to a Horizontal Angle of 0deg.
  5. Adjust lamp lumens and electrical information as necessary.
  6. You can pattern/mate/move/etc the lamp part just like any other Solidworks part.
Rhino
  1. In your model, choose Add Lamp from the Photopia menu or toolbar.
  2. Scroll thru the lamp list or type a keyword in the Search box.
  3. Rhino Add Lamp Dialog
  4. Click on your choosen lamp in the list.
  5. You may edit any of the Lamp Properties before you insert it.
  6. Click Add Lamp to begin placing the lamp.
  7. Either type in a coordiate at the command line or use the mouse to click the lamp into place.
  8. You may move/rotate/array/copy the lamp just as any other CAD item.

Updating A Lamp

SOLIDWORKS
  1. Right click on the Lamp part and choose Edit Lamp from the right click contextual menu.
  2. Adjust lamp lumens and electrical information as necessary.
Rhino

Within Rhino you can modify a single instance of a lamp, or all instances that you select. This makes it easy to update the lumens of all lamps at a single time.

  1. Select the lamp in the CAD model.
  2. Go to the Photopia Lamp panel.
  3. Adjust lamp properties.
  4. Click Modify selected lamp.

Using an IES file for a lamp

If your luminaire uses LEDs with off the shelf secondary optics from companies such as Ledil, Carclo, Fraen, etc. they may be represented using a special set of lamp models in Photopia's library. The special lamp models consist of planar geometry and will emit light in a distribution driven by the IES file you assign to it. The light will be emitted uniformly from the front surface of the lamp geometry. We have created a range of models that can be used for various sized optics. You will see them in the lamp list with names that begin with "LEDLENS..." The rest of the name indicates the geometry of the source, with a single number indicating a diameter. Some of these lamp models also include several copies so you can work with multiple lens types in the same luminaire. In this case, the extra copies have numbers at the end of their name. Some of these models include:

  • LEDLENS20MM (This has a round emission area)
  • LEDLENS50MM (This has a round emission area)
  • LEDLENS75MM (This has a round emission area)
  • LEDLENS19x95MM (This has a rectangular emission area for symmetric beams. It is sized for the Ledil Florence product line.)
  • LEDLENS95x19MM (This has a rectangular emission area for asymmetric beams where the main throw is perpendicular to the long axis of the lens. It is sized for the Ledil Florence product line.)

To set the lamp model's IES file, just rename your IES file to match the model name you want to use and put it into the following folder: C:\ProgramData\LTI Optics\Library\Lamps

Note that this folder is sometimes hidden by Windows, so if you don't see it in Windows Explorer then change your Folder Options to display all hidden folders and files.

Once you load the lamp into your model, then you will set its lumens, LED watts and driver watts in the lamp properties screen to define the values appropriate for your LED, its running current, temperature and lens efficiency.

SOLIDWORKS

To update the IES file for your simulation, just update the IES file in the folder and re-run your simulation. The raytrace will use the latest data in the Library folder at the time you begin the raytrace.

Rhino

If you update the IES file after you have already added it to your model, then you will need to reload the lamp as Photopia stores the lamp data originally imported within the model. To do this type "PhotopiaAddLamp" into the command line, then type in the lamp name, then choose the option "ReloadLamp".

LIMITATIONS

Light is emitted uniformly from the planar emission area, which is an approximation.

If you have lenses or reflectors close to the emission areas, they may not perform as they really will.

Using Rayset Data

If you don't find your lamp model in our Library, one option is to obtain and use a Rayset file from the LED manufacturer.

Rayset files contain

Raysets can sometimes have confusing orientation and emission points, so it is always best to turn on 3D rays to be sure that the rayset is positioned correctly. To rotate or move the rayset, you'll just rotate and move the lamp you placed there.

LIMITATIONS

Rayset files contain the emission points of the rays.

There are many examples where the emission points in these files are not truly representative of the actual emission point.

Here is a summary of rayset limitations.

SOLIDWORKS

Photopia for SOLIDWORKS can use .rir formatted rayset data (grayscale based rayset data) as the emission source. To use this:

  1. Choose Add Lamp from the Command Manager.
  2. You'll need to pick a current lamp model, so choose something with similar geometry.
  3. Expand the Options section to reveal additional options.
  4. Click Browse to find your .rir rayset file.
  5. Turn on 3D rays by going to Raytrace Settings.
  6. Run an analysis as usual.
  7. View 3D Rays by clicking Show/Hide 3D rays
  8. Rotate or move lamp as necessary to ensure proper ray emanation points.
Rhino

Rayset based lamp models are not currently supported in Rhino. This feature is coming soon.

Assigning a lamp to your Part geometrySOLIDWORKS Only

The following instructions describe how to create the solid part geometry for an existing Photopia lamp model.

  1. Import or construct the geometry of your lamp model in a new SW part file. Note that most lamp manufacturers post STEP files for their parts on their websites. The lamp model part can be in any units as long as it is the correct size.
  2. Move the lamp geometry so that it is centered around the part origin (0,0,0). Set up the geometry so that the center of the luminous area (the center of the chip faces for LEDs) is at 0,0,0. The geometry should be rotated so that the light emits toward the -Z direction and if you have a an array of LEDs along a PCB then orient its length along the Y axis. If you have a single emitter with geometry that isn't quadrilaterally symmetric, then load that LED into Photopia's standard CAD system and see how it is oriented with respect to Photopia's world coordinates and used that same orientation within SOLIDWORKS.
  3. Add a reference coordinate system and name it "Lamp orientation." This should be added at the origin of the part and match the part's XYZ axes. Do not mate this coordinate system to anything and it will insert at (0,0,0) by default.
  4. Set the name of the part to match the lamp model LDF file name. Note that lamp models that include reflective and/or refractive components, such as the dome lens on the Cree XM-L, will have a name that has "Core" added to what is shown in the Lamps.xls file. You can confirm the lamp model LDF name by loading the lamp in Photopia. The name will be shown in the LAMP layers and also as the text on the lamp axis layer.
  5. With the reference coordinate system selected, choose Add Lamp from the Photopia menu and pick the lamp model you are creating from the list to get that lamp's attributes added to this part.
  6. Save the part with a name that matches the lamp model LDF file name.
  7. Add this part file the following folder: C:\ProgramData\LTI Optics\SolidWorks\Library\Lamps
  8. Next time you add this lamp to a project you should see your new geometry.

Photopia models a wide range of material optical properties for various types of optical surfaces. The 3 general types of materials include:

Reflective - Materials that only reflect light. The reflected light can be specular, scattered or a combination, with properties varying by the light incidence angle. Reflectance properties can be defined as constant for all wavelengths or variable by wavelength. The wavelength range can be defined anywhere within the UV, visible or IR range.

Transmissive - Materials that both reflect and transmit light. The same properties defined for reflective materials can also be defined for transmitted light. Transmitted light can pass straight through a surface as a “specular” component, scatter or a have combination of both specular and scattered components. Transmissive materials are generally used to model light through diffusing lenses or lenses with repeated structured patterns such as prismatic lenses.

Refractive - Materials that model light via effects described by Snell's Law of Refraction and Fresnel's Equations. Thus, rays refract into and out of the material based on the indices of refraction of the outer and inner materials. Rays can totally internally reflect (TIR) inside of the material when incident upon the exit surface beyond the critical angle. Rays partially reflect/transmit at each optical interface based on Fresnel's Equations. Light is absorbed inside of refractors based on the material extinction coefficient. Refractive materials are generally considered to be clear (non-scattering) with smooth outer surfaces, but can include scattering properties on the outer surfaces as well as volumetric scattering from particles within the material.

Reflective and transmissive material properties are measured in our own optics lab with a custom-built HDR imaging based BSDF measurement device and custom-built integrating spheres. Spectral reflectance and transmittance properties can be measured from 200 - 1100nm. The light scattering properties (BSDF data) is measured at a wide range of light incidence angles for both isotropic and anisotropic materials. The total integrated reflectance & transmittance values are also measured over a wide range of light incidence angles.

All materials that include a wavelength range in their description have properties that vary by wavelength over the specified range. Such materials should only be used with light sources that emit within the same wavelength range. All materials without a wavelength range in their description have properties that are constant for all wavelengths in a simulation. Unless a specific wavelength is indicated in the material description, the material properties are generally appropriate over the visible range (380-780nm). Refractive materials for the visible range use a single index of refraction generally measured at the sodium D-lines, 589nm, which is very close to the center of the visible spectrum.

When using spectral materials, you need to use the "Power Distribution" raytrace option. This forces the raytracer to track spectral properties on each ray. This option is more memory & computationally intensive, so it isn't the default raytrace setting when the lamp flux energy units are set to lumens. The power distribution raytrace is not required for lumen based simulations since lamp spectral lamp properties within the visible can be represented with just 3 tristimulus values. Tristimulus values are all that's required since all color metrics can be derived from tristimulus values, including RGB display values, chromaticity values, color temperature, etc. Tristimulus values aren't sufficient for modeling dispersion, wavelength conversion with phosphors, computing photon flux, etc., so the power distribution mode is required for these types of simulations.

SOLIDWORKS

Photopia for SOLIDWORKS uses the SOLIDWORKS Appearance system to assign Photopia raytrace materials to parts. This allows you to assign materials to individual faces, features, bodies or parts, and lets you use the Appearance Manager to audit which surfaces have Photopia Materials assigned as well as Display States to maintain several configurations of your material assignment.

The Solidworks apperance system can be complicated and there is a hierarchy of appearances based on where they are assigned, so it is important to understand this system. You can view the Solidworks Appearance Hierarchy Guide here.

Rhino

Photopia materials in Rhino are managed via the Photopia panel . Photopia materials are separate/unique from the Rhino materials/finishes, which means you can keep your rendering materials assigned as well as your Photopia materials.

Assigning Materials

Lists of materials are provided within each CAD interface. You can also see a fully searchable material list that includes images for many of the materials.

Material spectral properties - Unless noted in the material description, the material properties are constant for all wavelengths. Materials with variable properties by wavelength include the wavelength range they cover at the end of their description.

SOLIDWORKS
Recorder Display Settings in Solidworks

The Photopia appearances are listed under the Photopia icon on the Task Pane on the right side of the screen. You can search the list by typing parts of a name or description in the box. You can filter the list by manufacturer or type. Selecting a material will show more details at the bottom of the pane.

There are several ways to assign appearances in SOLIDWORKS:

  1. A selected appearance in the list can be dragged into the model and dropped onto the geometry to which it will be assigned. A flyout menu will pop up allowing you to assign the appearance to a face, feature, body, part, or part at the assembly level.
  2. Pre-selecting a face, feature, body, or part in the FeatureManager and then double clicking on the Photopia appearance in the list will also assign the appearance.

Photopia for SOLIDWORKS uses the SOLIDWORKS Appearance system to assign Photopia raytrace materials to parts. This allows you to assign materials to individual faces, features, bodies or parts, and lets you use the Appearance Manager to audit which surfaces have Photopia Materials assigned as well as Display States to maintain several configurations of your material assignment.

Appearance Hierarchy

SOLIDWORKS geometry can have appearances assigned at multiple levels. For example, an appearance can be assigned to a part while a different appearance is assigned to a face on that part. In this case, the SOLIDWORKS appearance hierarchy will determine which appearance is used during the ray-trace. The same hierarchy is used for renderings in SOLIDWORKS. The order of the hierarchy is listed below. Levels higher in list supersede lower levels.

Controlling appearance order:

  1. Component Level Assignment (part@assembly level)
  2. Face Assignment
  3. Feature Assignment
  4. Body Assignment
  5. Part Assignment
Rhino
Recorder Display Settings in Solidworks

The Photopia materials are listed in the Materials panel. You can search on any part of the manufacturer, designation, or description, choose a recently used material or scroll the general list. The “Value” shown indicates the reflectance (ρ), transmittance (τ) or index (n) for reflective, transmissive, or refractive materials, respectively. This is also your indication of the material type. The reflectance and transmittance values shown are for the 0° incidence angle only.

To assign a material to model geometry:

  1. Select the geometry in the CAD view.
  2. Find the material you want in the list.
  3. Click the “Assign selected material” button or double click the material in the list.

Confirmation of the assignment will be shown at the bottom of this panel as well as on the command line.

Changing & Confirming Material Assignments

SOLIDWORKS

The Display Manager shows all appearance assignments in the model. Photopia appearance names are structured as “photopia + material filename.” The example below shows that the Photopia “Spec88” appearance is assigned to the “COB Reflector” part. To remove an appearance assignment, select the geometry in this tree view, then press the delete key. You can also reassign a new appearance to the same geometry to override the assignment.

Recorder Display Settings in Solidworks
Rhino

You can confirm the material assignment to geometry in Rhino by viewing the Photopia object settings in the Settings panel or by seeing what’s indicated in the Materials panel when the geometry is selected. Both panels provide a way to unassign the material or choose a new one.

Recorder Display Settings in Solidworks Recorder Display Settings in Solidworks

Solid Model Transmissive Materials

Transmissive materials use measured BSDF data to drive the ray reactions. The measured BSDF data accounts for the effects of the full material thickness. The full reaction of the material is applied to a single ray/surface interface.

When a CAD model is constructed with solids, a lens will have a thickness and the ray will pass through multiple surfaces. Special Solid Model versions of transmissive materials have been created to avoid the full effect of the material being accounted for multiple times as the ray passes through the multiple surfaces. The Solid Model version of the material is indicated with (s) at the end of the material designation in the material list.

Transmissive materials that have unique properties for each side, such as smooth on one side and textured on the other, will have the “front side” surface indicated in the material description. The front side faces to the outside of solid model geometry. If your model requires the “back side” surface finish to face toward the incident light, then you’ll need to use the non-solid model version of the material, also referred to as the “double-sided” version. The double-sided version should only be assigned to single surfaces, not the entire solid model geometry. In SOLIDWORKS, this means assigning the double-sided material to the appropriate face of the solid part. In Rhino, it means first exploding any solid geometry to surfaces, then assigning the double-sided material to the appropriate surface.

Anisotropic Materials

Anisotropic materials are materials where there is a grain or feature that create a scattering distribution that is a function of the horizontal incidence angle. Ribbed aluminum, linear prisms and elliptical diffusers are a few examples of anisotropic materials.

In the library anisotropic materials are identified by a (A) in the name and the word "anisotropic" in their description.

Just like other materials, the first step is to assign the appearance/material to the geometry using the same steps outlined above.

The next step is to orient the material which depends on your version of Photopia.

SOLIDWORKS
  1. Select the face, feature, body or part you want to orient the material on.
  2. Choose "Edit Photopia Appearance" from the Photopia tab of the Command Manager.
  3. You should then see arrows across each polygon. These show the 0deg azimuthal plane of the material orientation, which is indicated in the material description.
  4. You can adjust the orientation of the 0deg plane by setting the values in the property page.

If the arrows don't display, try orbiting since sometimes they are rendered behind the surface.

Rhino

In Rhino, the U direction corresponds to the grain direction in our library. In the material descriptions you will see the grain direction defined as the "arrow direction" (for Solidworks) and that arrow direction will correspond to the U direction. For forward throw anisotropic lenses, like wall wash diffusing films, the +U direction should point towards the wall.

You can view the u/v directions by typing dir at the command line, or going to Surface Tools > Show Object Direction.

To change the orientation of your material you should rotate the part and not use the U V Swap. The U V Swap can create invalid raytrace surfaces. It can be useful to run a short test with a laser source, your anisotropic part, and an illuminance plane, to confirm that your orientation of the part is correct.

If you do not have a rectangular part we would recommend first orienting the part and then trimming the part into the shape you want.

Volumetric Scattering

Beginning with Photopia 2017, Photopia supports volumetric scattering refractive materials. This is for materials which scatter light within their volume, usually via pigment or diffusion particles. These are a special class of Refractive materials, and as such require the General Refractor Module or Photopia Premium. Volumetric scattering can also be used along with spectral material properties to model phosphor particles suspended in a clear material. With a volumetric scattering material, your geometry will impact the scattering (thicker parts will scatter more).

Photopia uses a specific XML formatted file for defining the material properties. For Volumetric Scattering, the scattering is described by the Beer-Lambert Law. Photopia accounts for the extinction coefficient within the clear base material, the scattering coefficient (likelihood to scatter), the absorption of the scatter reaction, as well as the distribution and energy conversion of the scatter reaction.

Current Library materials with Volumetric Scattering are:

  • Evonik Acrylite LED EndLighten 0E011 L - for 12-24" wide sheets
  • Evonik Acrylite LED EndLighten 0E012 XL - for 24-48" wide sheets
  • Evonik Acrylite LED EndLighten 0E013 XXL - for 48-72" wide sheets
  • Generic 3000K phosphor particle in liquid silicone
  • Generic 3000K phosphor particle in acrylic

Full details are provided in this Volumetric Scattering Documentation.

Adding a Material to the Library

If you're looking for a material that you don't find in the Library, please let us know and we'll work on adding it. Often, you may use a custom material that isn't generally available. We can add this material to a custom library for your company. For information on getting a material in the Library, please see this order form.

Modifying a Material in the Library

You can modify the integrated reflectance of reflective materials, the integrated reflectance and transmittance of transmissive materials, and the index of refraction and extinction coefficient of refractive materials. The integrated reflectance and transmittance values can be changed as a function of incidence angle. You can also change the ratio of the specular component to the scattered light for both reflective and transmissive materials. You cannot edit the material BSDF data. The material file descriptions are as follows:

Reflective Material Files:

Filename.rfl - ASCII file of integrated reflectance values at each incidence angle. Files can contain an arbitrary angle set, so long as 0, 90 and 180 degrees are included. 0° is the front side of the material. Valid reflectance values range from 0.0 to 1.0.

Filename.brd - Binary file of the BRDF data for a material. This file cannot be modified. A .brd file only 2 bytes in size indicates the material is specular.

Filename.rsc - ASCII file specifying the ratio of the reflected light that is reflected in a specular manner. Note that these are not the specular reflectance values, but the fraction of the reflected light that is specular at each angle. To derive specular reflectance from these values, multiply these values by the reflectance at each incidence angle. Valid values range from 0.0 to 1.0. This file may or may not be associated with a material. A data byte indicating whether or not the material has a specular reflectance component is contained in the .brd file.

Transmissive Material Files (includes reflective files above, plus the following):

Filename.trn - ASCII file of integrated transmittance values at each incidence angle. Files can contain an arbitrary angle set, so long as 0, 90 and 180 degrees are included. Valid transmittance values range from 0.0 to 1.0.

Filename.btd - Binary file of the BTDF data for a material. This file cannot be modified. A .btd file only 2 bytes in size indicates the material is clear or image-preserving.

Filename.tsc - ASCII file specifying the ratio of the transmitted light that is transmitted in a straight-through manner. Note that these are not the straight-through transmittance values, but the fraction of the transmitted light that passes through un-scattered at each angle. To derive straight-through transmittance from these values, multiply these values by the transmittance at each incidence angle. Valid values range from 0.0 to 1.0. This file may or may not be associated with a material. A data byte indicating whether or not the material has a straight-through transmittance component is contained in the .btd file.

Refractive Materials Files:

Filename.rfc - ASCII file containing 3 values: the index of refraction of the outside medium (usually assumed to be air at 1.0), the index of refraction of the material averaged over the visible spectrum, and the extinction coefficient in units of inches. Note that the extinction coefficient is applied in the equation: Trans = e^(k*L), where e is the exponential (2.71), k is the extinction coefficient, and L is the distance the ray travels in the material in inches. Thus, k is a value per inch.

Spectral Material Files:

The spectral data for reflective & transmissive materials are defined in several different files. The .spdrfl & .spdtrn files include an incidence angle, multiplier and reference to a spectral matrix file (*.spdmatrix) on each line. The multiplier scales all values in the .spdmatrix file. The spectral reflectance & transmittance is defined in a matrix, where each row is an input wavelength, and each column is an output wavelength. For materials that don't shift wavelengths, all reflectance/transmittance values are shown for each wavelength along the diagonal of the matrix. All other values are 0. The first 3 values in the matrix file define the wavelength range as start, end, increment in nm. Wavelength increments can't be less than 1nm at this time.

The first 3 values in the .spdrfc refractor material files define the start, end and wavelength increment in nm. The remaining lines include the outside index, inside index and extinction coefficient for each wavelength.

Spectral materials also require a .material file.

To Modify Material Files:

You can modify any of the ASCII files described above with a text editor such as Notepad. Follow the instructions below to create a new version of a file without changing the original copy:

  1. Go to the C:\ProgramData\LTI Optics\Library\Materials folder in Windows Explorer. Be sure you are viewing the file extensions. If you don't see the ProgramData folder listed, then be sure that all hidden files and folders are being shown in Explorer.
  2. Find a material that has all of the same general characteristics as the new material you wish to create. For example, pick PAINT001 if you want a reflective material that has a specular component.
  3. Copy all of the files for the original material to files with a new filename of your choice. The filename prefix should not include spaces.
  4. Modify the data in the files as you require.
  5. The material lists shown in Photopia are read from .lib files. The default .lib files for the various material types are named Reflect.lib, Transmit.lib & Refract.lib file. Since these files are updated whenever Photopia is installed, any custom materials should be listed in unique .lib file names. So make a copy of the .lib file you need depending on your material type. Rename the filename prefix while preserving the original name that describes the type. For example, rename Reflect.lib to be Reflect_YourCompany.lib. These files are ASCII files, so open the new .lib file in Notepad. There are 5 entries on each line, with each data item separated by a tab character. The data is: manufacturer, designation, description, value (either 0° percent reflectance, 0° percent transmittance, or index of refraction), and material filename prefix. Modify the data on the first line of the file to represent your new material. Delete the remaining lines in the file. You can now add any number of new materials to this file later.
  6. Save and close the .lib file. The next time you open Photopia in SOLIDWORKS or Rhino, your new material will be listed.

Photopia has 2 types of recorders that collect flux density onto surfaces, recording planes & recording objects.

Recording planes are flat, rectangular surfaces that only collect light incident onto one side. Since their geometry is limited to flat rectangles, their grid resolution can be defined, and all grid values are available to view in the results. Geometry used to define recording planes can't also be optically active as a reflector or lens surface.

  • only planar rectangular surfaces
  • are not optically active (must not have a Photopia material assigned)
  • records incident energy on front only - 1 channel

Recording objects can be made for any reflector or lens optical surfaces in the model. Unlike recording planes, these surfaces can have any shape or curvature and must be optically active. The flux density is recorded on all mesh polygons of recording objects for incident and exitant light, for both the front and back sides of the object surfaces. So there are 4 sets of data (channels) for recording objects.

  • any surface shape (not necessarily flat or planar)
  • are optically active (must have a Photopia material assigned)
  • records incident and exitant on front and back - 4 channels

Create Recording Planes

SOLIDWORKS
  1. Select a planar rectangular face in your model. It is important that the face be planar, rectangular, and not already assigned a Photopia Appearance.
  2. Click "Add Recording Plane" from the Photopia CommandManager tab.
  3. Define the grid name and description.
  4. Confirm the Lower Left Corner of the plane, or shift as necessary. The lower left corner defines how the grid data will be displayed in reports.
  5. Confirm the plane direction. The front side of the plane is indicated by a blue arrow. Recording planes only collect light onto their front side, so the arrow should face toward your light source. Flip the orientation if necessary.
  6. Define the grid resolution by entering either column/row spacing or the number of columns/rows.

You can also check a box for “Enable fluence mode,” which converts the grid so that it collects “fluence rate” values rather than illuminance/irradiance values. Fluence rate is the total flux incident onto a sphere divided by the sphere cross-sectional area. The spheres are centered in each grid patch and have a diameter equal to the grid spacing. Fluence rate is a more useful metric of flux density for applications such as air and water disinfection where particles are equally affected/dosed by flux arriving from any direction. Fluence rate values multiplied by time of exposure in seconds equals “fluence,” which is the dose onto particles. Fluence rate has units of watts/area while fluence is joules/area.

Rhino
  1. First, confirm your planar face is oriented properly. The surface orientation can be checked and flipped with Rhino's “Show object direction” tool on their Surface Tools panel, or by typing "DIR" at the Command Line. The lower left corner is indicated with the red and blue U and V direction vectors as shown below. Recorder Display Settings in Solidworks
  2. Select a planar rectangular face in your model. It is important that the face be planar, rectangular, and not already assigned a Photopia Material.
  3. Click "Add Recording Plane" from the Photopia toolbar.
  4. Enter a plane name at the Command Line.
  5. Confirm the grid resoution at the Command Line.

In order to record Fluence select the plane and then go to the Photopia Object Settings and check the box for "Fluence Mode" which converts the grid so that it collects “fluence rate” values rather than illuminance/irradiance values. Fluence rate is the total flux incident onto a sphere divided by the sphere cross-sectional area. The spheres are centered in each grid patch and have a diameter equal to the grid spacing. Fluence rate is a more useful metric of flux density for applications such as air and water disinfection where particles are equally affected/dosed by flux arriving from any direction. Fluence rate values multiplied by time of exposure in seconds equals “fluence,” which is the dose onto particles. Fluence rate has units of watts/area while fluence is joules/area.

Modifying Recording Planes

SOLIDWORKS
  1. Select the surface/face in the CAD view.
  2. Right click and select the Recording Plane icon from the flyout menu.
  3. Change any of the desired parameters

Recording planes in SOLIDWORKS get their size and location from the surface at the time they are defined. If the surface is later moved, resized, or deleted, the change won’t be recognized by the recording plane. So if you need to modify a recording plane, then click the “Delete all recorders” button. Modify your surface and then redefine your recording plane and any other recorders in the model.

Rhino
  1. Select the surface/face in the CAD view.
  2. Go to the Photopia Object Settings panel. Pre-selecting the recording plane isolates the properties for the plane.
  3. Here you can also enable "Fluence mode".

The recording plane is associated with the surface used to define it, so if that surface is transformed or deleted, the recording plane will recognize the change.

Viewing Recorders

You can view recording planes & recording objects by choosing Results and then the Illuminance Planes / Recording Planes tab, or turning on their display in the Model view using the Recorder Display On/Off button.

Creating recording objects

recording objects allow you to view the light interacting with any object in your model. The object surfaces must be optically active, so they need to have a reflective, transmissive or refractive material assigned to them. If you don't want the object to impact the light in your model, you can assign the CLEAR001 transmissive material.

SOLIDWORKS
  1. Select one or more faces or objects in your model. It is important that you select the same level of geometry to which the Photopia appearance was assigned. So if the appearance was assigned to a face, then select the face, not the full part that includes the face. If you created a “Convert to mesh body” feature, then select that in the FeatureManager.
  2. Click "Add Recording Object" from the Photopia CommandManager tab. There is an option to enable or disable the recording object in this screen in case you need to make this change later.
  3. After a raytrace is complete, click on the "Show/Hide recorders" button in the Photopia CommandManager to display all recorders in the CAD view.
  4. The "REcording surface settings" button on the Photopia CommandManager tab allows you to specify the way the recorders are displayed. See information below for more details.

The recorder mesh resolution is set by default by the Image Quality settings in SW, under Settings / Document Properties. Slide the top bar labeled "Shaded and draft quality HLR/HLV resolution" into the red zone for a finer mesh. More detailed options are available in SW2018 and later by adding "mesh body" features to your part geometry. This is done in your part by choosing "Insert / Surface / Convert to Mesh Body…" You are then prompted to select a body from the part. If a body represents a solid, then a single mesh will be made that represents all faces of the solid. If you want to create separate meshes for each face, which is helpful when viewing surface statistics (max, min, average, ...) in the recorder report, then you should build the model geometry from surfaces rather than solids. You can then select the surfaces from the list of bodies to convert to a mesh. Be sure that you also assign the Photopia appearance to the mesh feature and select the mesh feature before clicking the "Recording object" button.

Rhino
  1. Select one or more objects or surfaces in your model.
  2. Assign a Photopia material if you have not done so already.
  3. In the Photopia Settings panel , click the "Photopia object settings button."
  4. Find your object/surface and check the "Record" box. If you first select your object in the CAD view, then it will be isolated in the list.
  5. After a raytrace is complete, click on the "Show/Hide recording surfaces" button on the Photopia toolbar to toggle the display of the recording surfaces.
  6. The "Recorder display settings" button in the Photopia Settings panel allows you to specify the way the recorders are displayed. See information below for more details.
  7. The Recording object mesh resolution is set with the "Mesh parameters" button on the Photopia toolbar.

Recorder Display Settings

SOLIDWORKS
Recorder Display Settings in Solidworks
Rhino
Recorder Display Settings in Rhino

Predefined Render Scripts: Render Script Presets allow you to select from a default set of display settings, including: false color, true color, grayscale, spectral shifts for non-visible wavelengths and Delta u'v' for color uniformity.

Render Script: Once a preset render script is selected, then the render script will be displayed in a separate box. All values of that render script can then be edited to manipulate the recorder display even further.

Global Max: By default, all recorders will be scaled to the global max value found on all recorders. The global max is automatically found when the "Global scale max" parameter is set to 0 in Rhino. You can enter any other value there if you prefer.

Legend: A legend is displayed when using global scaling and viewing gray scale or false color plots. If you uncheck the "Global scale enabled" box in Rhino or switch to local scaling in SW, then each recorder will be scaled according to its own max value. A legend can't be displayed in this case since the same colors will represent different magnitudes. When global scaling is used, the value of red on the legend is based on both the max value found on all recorders as well as the area over which that max is achieved. If the max is only on a very small area, indicating “noisy” results, then red will be assigned to a lower value to allow then colors of the legend to represent more of the data on the recorders. The true max value will be shown to the upper left of the legend display.

Global Recorder Smoothing: The "Global recorder smoothing" option determines whether or not the data on each patch is blended with neighboring patches. Smoothing the data makes a more realistic looking image of the light pattern. If you turn off the smoothing, then you see the raw data in each patch of the recorder.

Channel: This allows you to view any of 4 data sets on the surfaces. The channels are the incident light onto the front and back sides of the surfaces as well as the exitant (emitted) light from both the front and back sides. All 4 channels are available for recording objects, but only on the front incident light channel is available for recording planes.

Delta u'v' from average: The "Delta u'v' from average" plot allows you to view quantitative color differences in the uniform u'v' color space. In this color space, a value of 0.001 is 1 MacAdam ellipse, which is a just perceptible color difference. Beam color uniformity requirements sometimes specify an allowable range in this color space, such as 0.004 or 4 MacAdam ellipses. In this plot, black is 0 and bright green is the highest delta u'v' value on the plane. This plot type supplements the true color plot when color differences in the light pattern are subtle, especially for tunable white lighting applications.

You'll need to tell Photopia how to orient your Photometric Coordinate System before raytracing. You'll basically be defining what is 'up/down & forward/back, which should be the same orientation as the test. You can find more explanation of photometric conventions here.

SOLIDWORKS

First, it is easiest to insert a reference coordinate system based on the following convention: -Z is Vertical Angle = 0, +Y is Horizontal Zero. The origin of this coordinate system should be located at the center of the luminous opening of your fixture.

Then go into the Photometric Settings menu, set the horizontal and vertical angles based on your fixture type and symmetry. You'll see a wireframe sphere or hemisphere which shows the test region. The wireframe density indicates the location of the test data points. The shaded portion of the wireframe indicates the final output angles in the photometry based on your symmetry. After setting the angles, exit out of the dialog with the green check.

Insert a mate between the "Reference" coordinate system and the coordinate system you created. This will move and reorient the photometric coordinate system.

Rhino

Click the toolbar button for the Photometric Output Settings

Rhino Analysis Tutorial - Photometric Settings

Here you'll set the vectors for Photometric Nadir and Azimuth.

You can visually confirm your coordinate system because Photopia draws a sphere in the CAD window to show you the test angles. Each zone is represented, and the fully shaded zones are the final averaged zones in your output file.

This screen allows you to modify the parameters that control all aspects of the raytrace process. The following sections provide a description of each of the parameters.

SOLIDWORKS
Solidworks Aerospace Tutorial - Angle Conventions
Rhino
Solidworks Aerospace Tutorial - Angle Conventions Solidworks Aerospace Tutorial - Angle Conventions

Ray Count

Specifies the number of rays for the raytrace, emitted from all sources combined. The more rays that are traced, the more refined the results. The default of 2.5 million is generally sufficient for initial results.

Each component of the results will resolve at a different number of rays.

Below is the order in which items typically resolve.

  1. Optical Efficiency (~50,000 rays)
  2. Intensity Distribution (~2,500,000 rays with 5deg vertical angular resolution)
  3. Recording Planes (~10 to 25 million rays at 100x100 grid size)
  4. Color Difference (~100+ million rays)

Reaction Count

Specifies the number of ray reactions to trace. Each ray intersection with an optically active surface is a ray reaction. The default of 25 is generally sufficient for most light to emit from or diminish within an optical system. The “Reached interreflection limit” value in the “Anomalous interactions” section of the “Raytrace Report” indicates how much light was still interacting within the optical system due to this limit. It's generally best to set the reaction count high enough so that only a small percentage of the light reaches this limit. Light pipe/light guide designs or refractors with volumetric scattering particles generally require much higher values, such as 100+ ray reactions.

Lamp Flux Energy Units

The simulation can be run with the lamp output defined in lumens, radiant watts, photon flux or PAR photon flux. Lumens are appropriate for all lighting applications for which photometric output is required. Radiant watts provides radiometric output for applications such as optical sensors, UV curing and disinfection. Photon flux or PAR photon flux are most commonly used for horticulture applications. Both "Photon flux" and "PAR flux" are based on the lamp output in micro-mol photons per second. Photosynthetically Active Radiation (PAR) flux limits the results to only wavelengths between 400-700nm. Most horticulture applications require the use of PAR flux.

When you are using lamp models that include their full spectral details, then the lamp output can be defined in lumens, radiant watts, photon or PAR flux. They are all linked by the lamp SPD, so entering output in any of these units automatically updates all of the others. If you only know the lamp output in lumens based on the LED datasheet and power parameters for example, then you can enter the output in lumens even if you want results in PAR flux. Just be sure to set the lamp flux energy units in the raytrace settings as you require before the raytrace is run. Photopia does the proper conversion from radiant watts to photon flux at every wavelength of the SPD in the intensity distribution and on irradiance planes. So you can mix any combination of white and colored LEDs and get the right PAR flux values, for example. It is important that the SPD for the lamps you choose from Photopia's library match your actual LEDs if you will be relying on the right conversion from lumens or radiant watts to PAR flux. Entering your LED output in PAR flux directly avoids the need for an exact SPD match, but the LED output in PAR flux is not always provided on datasheets.

Ray Shadowing

Used for ray generation, this ensures that lamp parts which shadow the emission are taken into account. Leave checked for the most accurate results.

Minimum Ray Energy

If a ray's energy falls below this setting, it will no longer be traced through the system. This helps speed up a raytrace by reducing time spent on insignificant rays. The amount of light lost in the raytrace due to this limit is reported in the “Anomalous interactions” section of the “Raytrace Report.”

Exclude Reactions

Enabling this option allows you to remove any number of initial ray reactions from the output, starting with ray reaction 0. This allows you to isolate any part of the output by the ray reaction number to more clearly see “higher order” effects and help isolate their cause. For example, if you have a reflector design that emits both direct and reflected light, you can isolate the beam created from the reflector by removing the 0th ray reaction from the output. You enter the Exclude reactions through value, which would be 0 in this example. Note that some LED models include optically active components such as a primary lens, so in this case your “exclude through” number would need to be increased to account for the ray reactions within the LED package.

Update Frequency (seconds)

Specifies how often the output will be updated as the raytrace progresses. The analysis status view will show the # of rays and percent complete with each update.

Power Distribution Raytrace

This option enables the full spectral data to be tracked with each ray. This is the most general way of tracking ray properties, but results in a slower ray trace since more data is processed with every ray reaction. When running a lumen based simulation that does not use any materials with spectral properties, you can leave this option disabled and all spectral properties will be converted to tristimulus values. Thus only 3 extra parameters are tracked & processed on each ray, resulting in a faster ray raytrace with less memory and storage. Tristimulus values are all that's needed to compute all color metrics including the true color recorder images. If the lumen based simulation includes spectral materials, which are indicated with their spectral range shown in their description, then you need to enable the power distribution raytrace for those material properties to be used. For example, if you want an acrylic lens to use an index of refraction that changes by wavelength, then choose the ACRYLIC1 material with a description of “standard clear acrylic (250-2800nm)” and enable the power distribution option.

All radiant watt or photon flux simulations automatically enable the power distribution raytrace since their output requires the full spectral ray data.

When a power distribution raytrace is enabled, you can also specify the resolution in nm. A finer resolution might be needed for models that include narrow band features in their lamps and/or materials. The finer the resolution, the more data tracked on each ray, and thus the slower the raytrace and the larger the memory requirements.

Preserve Power Distribution Data

This option refers to the spectral power distribution data stored with recorders. When a power distribution raytrace is run, all spectral data can be stored for each patch of every recorder in the model. This data is needed if you will be using any of the render display scripts that remap the spectrum for visualization purposes. For example, if you plan to remap UV wavelengths into the visible range so that you can view the recorders in a way similar to true color displays, which show both color mixing and irradiance magnitude in the same display. Having the full spectral data available for such display options is helpful, but it also requires more memory. This is OK for a few recording planes at their default resolution, but can become a burden on system resources when you have large recording objects with hundreds of thousands of polygons, especially since recording objects store 4 channels of data for every polygon. So it's best to leave this option off unless you specifically need the spectral remapping feature for recorder display visualization.

Sample Ray Count

The number of rays that you want displayed in the CAD view. The default of 0 results in no displayed rays. When you do want to display rays, we recommend a fairly low number such as 500 so that you can more clearly see the general ray trends. Using too high a number fills the screen with so many lines that it can be difficult to see their interactions with the model geometry. You may need to use a higher number however, when filtering the rays to see how they react with specific optical components in the model.

Sample Ray Length

The length of the ray after its last interaction with any optical components in the model, including recording planes. This value can be changed after the raytrace in Rhino and the ray display will update.

Sample Ray Filtering

For each sample ray, Photopia keeps track of several properties of that ray, including the objects that it interacted with. This allows you to filter the sample rays to display only the rays that fit a specific criteria.

SOLIDWORKS
Solidworks Aerospace Tutorial - Angle Conventions

Click the Filter sample rays button on the Photopia CommandManager to open the following PropertyManagement page.

Show rays by object - Display rays that interact with all objects in the model or only those you select. Note, “farfield” is the far field photometric sphere. It’s listed as both a material and an object.

Show rays by material - Display rays that interact with all materials in the model or only those you select.

Range of reactions to filter - Defines the start and end ray reaction numbers to display.

Expert advanced ray filtering – - You can type a list of ray reaction numbers to show. The numbers do not need to be consecutive. Use a space between each value.

Invert filter - Inverts the current filter setting so all rays that were not being displayed are now displayed while the filtered rays are not.

Filtered Ray Color - Specify the filtered ray color in the box just after Invert filter. The red, greed & blue values are specified from 0 to 1, separated by spaces.

Rhino
Solidworks Aerospace Tutorial - Angle Conventions

Click the Sample Ray Settings button in the Photopia Settings panel to view the screen.

Sample ray color - Set the color of the unfiltered sample rays. To change the color, click on the color designation, then click the drop-down arrow in the cell and choose a color on the pop-up dialog.

Exceptional ray color - Set the color of exceptional rays. These are rays that were stopped in the raytrace due to the problems listed in the “Anomalous interactions” section of the “Raytrace Report.”

Filter enabled - Check this option to view the filtered rays as defined by the following settings. When unchecked, all sample rays are displayed.

Display exceptional rays - Check this option to display the exceptional rays.

Invert filter - Inverts the current filter setting so all rays that were not being displayed are now displayed while the filtered rays are not.

Filter from reaction - The start reaction number of the rays displayed.

Filter to reaction - The end reaction number of the rays displayed.

Filter color - Set the color of the filtered rays.

Object filters - Display rays that interact with all objects in the model or only those you select. Note, “farfield” is the far field photometric sphere. It’s listed as both a material and an object.

Material filters - Display rays that interact with all materials in the model or only those you select.

Saving Sample Rays as CAD Entities

SOLIDWORKS

The filtered rays can be saved to a 3D sketch in the assembly. If you want to save all rays to the sketch, then keep the default filter settings that show ray reactions with all objects & materials. When finished defining the filter settings, click the Save filtered rays to sketch and close button at the bottom of this PropertyManagement page. A new 3D sketch will be created to store the filtered rays. If you want to separate different sets of rays into different 3D sketches, then define a new filter and click the same button when closing this PropertyManagement page.

Rhino
Solidworks Aerospace Tutorial - Angle Conventions

Choose Photopia > Save 3D Rays from the main menu. This will save the 3D rays displayed with the current filter settings to the current layer. If you want to save different sets of rays to different layers, then change the filter settings and current layer as desired.

Mesh Resolution

The Photopia raytrace engine uses a meshed model for the raytrace. Rhino and Solidworks bodies are natively surfaces, not meshes, so they must be converted before raytracing. This conversion is handled automatically when you begin a raytrace, but you may need to override the default meshing for parts with fine details.

For smooth lenses or detailed geometry, we recommend using the Maximum Angle and set it to 1 or 0.5deg.

For recording objects, we recommend using the Maximum Element Size and Max/Min Edge Length to set a reasonable cell size.

SOLIDWORKS

In Solidworks, the default resolution will generally work well.

For any sensitive or small parts, the best approach is to create a Mesh Body from your Body (in Solidworks 2018 or newer).

Mesh Body

  1. Open the Part file, or edit the Part within the assembly.
  2. Choose Insert > Surface > Convert to Mesh Body ...
  3. Select the Body to convert
  4. Update the resoultion settings, we suggest setting the Maximum Angle Deviation and Maximum Element size.
  5. Solidworks Aerospace Tutorial - Angle Conventions
  6. Click check and you'll see the new mesh
  7. Assign the Photopia Appearance to this Mesh Body.

For Solidworks 2017 or older, you can control the resoution to some degree using the Image Quality settings. This method cannot generate a mesh as high resoution as the Mesh Body approach.

Image Quality

  1. This setting should be applied within a Part file.
  2. Choose Tools > Options > Document Properties > Image Quality
  3. Find the Shaded and draft quality HLR/HLV Resoultion section
  4. Pull the slider into the red zone.
Rhino

In Rhino, click on the Photoia Mesh Settings.

You can adjust any of the parameters and then click Preview to see the mesh for your model.

Any setting kept at 0 will be non-controlling.

Maximum edge length and Maximum Angle are the two most useful settings.

Solidworks Aerospace Tutorial - Angle Conventions

Results can be viewed either in the SOLIDWORKS window, Rhino panel or in Photopia Reports. This allows you to view several outputs at the same time.

Results are saved in the configuration they are run in with Solidworks, so you can maintain multiple saved results if you have multiple configurations in your Solidworks model.

Currently we show the following results:

  • Photometric report, including efficiency, candela distribution, zonal lumens, beam angles, CUs and roadway typings
  • Candela Plot
  • Illuminance planes, including shaded, text and summary data which can be saved to a file
  • IES file which can be saved
  • Analysis Status

The Parametric Optical Design Tools (PODT) create reflector and lens geometry based on how you want to control the light. The parameters for the various types of optics define both the physical size and aiming properties of the design. These tools are useful when you are designing a reflector or lens that needs to produce a particular beam pattern. The optical design tools allow you to define the range of angles over which the light is directed as well as how much light is directed toward each angle in the beam. Thus, they allow you to tailor the beam intensity distribution.

Reflector Design Tool Overview

The reflector design tools create reflector profiles based on aiming light toward a range of angles or toward a range of points. Using “aim by angle” creates a reflector built from a set of parabolic sections. Using “aim by point” creates a reflector built from a set of elliptical sections. As an example, consider a reflector that aims all light toward a single angle at the beam center, creating a very narrow beam pattern. This reflector is a single parabola that collimates light as shown below when revolved into a parabolic surface:

Photopia Parametric Optical Design Tools - PODT Profile

The aiming angle in the reflector above is toward the 0° vertical angle in the reflector's intensity distribution. Now consider changing the aiming angle to be 20° away from the beam center, as shown below. This is still a single parabolic profile, but the profile has been rotated by 20° about its focus. Revolving this profile about the beam central axis (a vertical line), results in the reflector shown below. Whereas the reflector aimed toward 0° would create a narrow beam intensity distribution, the reflector aimed at 20° would produce beam pattern with a spike 20° off center.

Photopia Parametric Optical Design Tools - Cross Aimed Parabola

The parametric reflector design tools allow you to aim light toward any number of angles in your beam pattern, which results in a set of parabolic profiles all joined together. Combining 0 and 20 into a single reflector looks like this.

Photopia Parametric Optical Design Tools - Mix Aimed Parabola

Simulating these 3 reflectors with an LED at the focus results in the following intensity distributions.

          Photopia Parametric Optical Design Tools - Mix Aimed ParabolaPhotopia Parametric Optical Design Tools - Mix Aimed ParabolaPhotopia Parametric Optical Design Tools - Mix Aimed Parabola

The relative intensity values at 0° and 20° in the 3rd beam are determined by how much of the reflector is allocated to each of the 2 parabolas. More specifically, each parabola gets some fraction of the total reflector angular extent. The total angular extent is the angular sweep about the focus from the bottom to the top of the reflector. In this case, it’s about 53°.

Photopia Parametric Optical Design Tools -

The reflector above with sections aimed at both 0° and 20° allocated 40% of the total extent to 0° and 60% toward 20°. Changing that allocation to 20% / 80% results in the following intensity distribution.

          Photopia Parametric Optical Design Tools - Photopia Parametric Optical Design Tools -

Since less of the reflector is collecting and redirecting light from the LED toward 0°, the intensity in that direction is reduced relative to the intensity at 20°. So in addition to the parametric reflectors allowing you to define the range of angles over which the reflector is aimed, they also allow you to manipulate the fraction of the reflector aimed toward each angle in the distribution. This is done by assigning a set of “weighting factors” to each reflector “aiming section.”

The reflector below shows a more realistic design, with aiming sections ranging from 0° to 20°, every 1° in between. This reflector is therefore comprised of 21 parabolic profiles all joined together. The weighting factors (WF’s) were defined so that they created a beam with a peak in the beam center that tapered off toward the wider angles in the distribution.

          Photopia Parametric Optical Design Tools - Photopia Parametric Optical Design Tools - Photopia Parametric Optical Design Tools -

The image below illustrates the geometric input parameters for a reflector, including +/- angular conventions. The Lamp Center is the focus of the optic, the Nadir Direction defines the beam center, and the Start Point defines the fixed end of the reflector. The start point can be set at the top or bottom of the reflector. The Angular Extent defines the total angular size of the reflector. The “end point” of the reflector floats along the angular extent cutoff line with a location based on the profile shape, which is driven by the aiming parameters.

Photopia Parametric Optical Design Tools -

The aiming method is selected as “by angle” or “by point.” When using “by angle,” the angular conventions are as defined in the above image. When using “by point,” you enter the absolute points in the sketch or construction plane. Aiming angles are defined for each end of the reflector, with an Aiming Angle Increment that determines the total # of reflector sections between the 2 extremes. Aiming points are defined for each end of the reflector, with the Number of Points used to define the total # of reflector sections

Creating a Reflector

SOLIDWORKS

The parametric reflector will be created in a part document. A parametric reflector profile can be created in any sketch plane. If you want to create a profile so the light is aimed along the world Z axis, in line with the default lamp model orientation, then create a new sketch in the Top Plane. Once the sketch is created, then some initial geometry needs to be added to define the geometric constraints of the reflector. These include the Lamp center, Start point and a construction line that defines the 0° aiming angle. You may want to use the sketch origin as the lamp center. Add a Point to define the location of the start point. Add a construction line to define the 0° aiming angle. This is often a vertical line anchored to the sketch origin.

Once the input sketch geometry is created, select Photopia > Design Reflector and reference the geometry from the sketch in the various input parameters. The Angular extent is a parameter that could not be easily referenced, so this value is manually entered. You can determine it in your sketch via a smart dimension before starting the design tool.

Reload - This keeps a reference to reflector parameters that have been defined. Most often you only create 1 profile for a given sketch, but if you create multiple then they will be referenced in this list. This drop-down list is most often used to select the parameters to associate with a feature created from the sketch after the profile is completed.

Lamp Center - Select a point that defines the lamp center, the focus of the aiming parameters.

Start Point - This defines the start point of the reflector. This is the fixed end of the reflector and can be at the top or bottom of the profile.

Angular Extent - The full angular extent of the reflector, measured about the optical center and beginning at the start point. CCW is a positive angular sweep, CW is negative.

Edge for 0° aiming angle - Select the construction line that defines the 0° aiming angle, generally the beam center.

Aim by direction / Aim by point - Select the aiming method and define the aiming angles or aiming points.

Target Feature - A feature based on this profile does not exist at the start, so leave this reference blank. It will be referenced after the profile is added to the sketch and a feature is created.

Open the PODT Window - This button will open the PODT window where you can adjust all reflector properties.

Advanced - - Includes the “Create TIR Profile” option, which encloses the reflector profile sketch to create a solid mass of material when revolved or extruded. Otherwise, the profile created by this tool is a single curve that is generally revolved into a thin shell, as shown in the left image below. The right image shows the revolved feature created from the “TIR Profile” option that includes lines connecting the reflector curve to the central revolve axis. This is useful when using the reflector design tool to design TIR lens optics.

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Rhino

A reflector profile can be created in any construction plane. The Front View is often used when creating a reflector aligned with the default photometric coordinate system. Once you've selected your construction plane, then click the “Design reflector” icon on the Photopia toolbar and follow the command prompts for the input parameters.

Lamp Center - The focus of the reflector aiming sections. Often the origin of the construction plane.

Aiming nadir - The direction of the beam center and 0° aiming angle. This is often in line with the -Y direction. Hold down shift and drag your mouse down to indicate a direction straight down.

Start Point - The start point of the reflector. This is the fixed end of the reflector and can be at the top or bottom of the profile.

Angular Extent - The angular sweep of the reflector can be selected with the cursor or a value can be entered. CCW is a positive angular sweep, CW is negative.

Type of aiming - Enter “D” for Direction or “P” for Point.

Aim by direction / Aim by point - Select the aiming method and define the aiming angles or aiming points.

Aiming start, end & increment - For aim by direction. Enter the desired aiming parameters.

Aiming start, end & aiming section count - For aim by point. Enter the desired aiming parameters.

Choose to open the PODT dialog or skip it. If skipped, the reflector profile will be added to the current construction plane. To edit the profile parameters, select the profile and click the “Design reflector” icon again. This will open the PODT dialog.

Reflector PODT Window / Dialog

All the parameters of an optical profile can be viewed and modified in the PODT window.

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Aim by angle - The aiming angles for the start & end of the reflector as well as the angular increment between the 2 extremes. The angles are measured from the nadir direction. Click "Update Aiming" to apply changes.

Aim by point - The start & end aiming point locations within the sketch/construction plane coordinate system, as well as the number of points in between. Click "Update Aiming" to apply changes.

Optical center X/Y - The focus of all reflector aiming sections in the sketch/construction plane coordinate system.

Start X/Y - The start point of the reflector in the sketch/construction plane coordinate system.

Curve resolution - The angular resolution of the polyline profile used to approximate the parabolic or elliptical reflector sections. The curve resolution defines the angular sweep about the optical center, starting from the beginning of each aiming section, at which vertices of the polyline profile are obtained. To get a reflector profile that closely approximates the parabolic/elliptical profiles, use a small value such as 0.5° or 1°. To create a “faceted” reflector profile, use a larger value. To create a single facet for each aiming section, use an angle that is larger than the size of all aiming sections, such as 90°.

Angular extent - The full angular extent of the reflector, measured about the optical center and beginning at the start point. CCW is a positive angular sweep, CW is negative.

Number of sections - The number of aiming sections determined by the aim by angle or aim by point parameters. This value can be overridden if you need to add or subtract sections from what the aiming parameters defined.

Calculate weights - A value of “On” enables the use of the weighting factor (WF) equation.

Weight exponent - Exponent in the WF equation. A higher positive value directs more light toward wider angles. A lower negative value directs more light toward the beam center. A value of 0 sets all WF’s to the minimum value.

Weight minimum - Sets a minimum WF value in the nadir (0°) direction.

Weight shift - Shifts the angle in the cosine function of the WF equation. Useful when your beam is directed toward a surface that is not centered about the nadir direction. For example, when illuminating a vertical wall with a ceiling mounted luminaire, using a weight shift of 90° produces a more useful trend in the WF’s.

Weight adjustment - An adjustment factor that can be applied to the calculated weights for each aiming section.

Lens Design Tool Overview

The lens design tool shares the same aiming and weighting factor parameters as reflectors, but uses refraction instead of reflection to redirect the light. Because lenses/refractors control light differently, they require different geometric constraints.

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Whereas reflector shapes are determined by their aiming parameters, lens shapes are more flexible and generally defined by the style of the optic. For example, the prisms shown in the image above could be “mapped” to the flat “base profile” shown or a curved “base profile” like shown below depending on the style of the optic. The same type of aiming can be defined for either “base profile,” but the prism geometry will vary depending on shape of the base profile. To accommodate different styles of optics for any given application, the “base profile” is one of the input parameters.

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Lens designs also require a material index of refraction and the material thickness since the light will refract through 2 surfaces. All lenses start as prismatic profiles as shown in these images. Once the initial lens definition is created, a larger range of parameters are available to modify in the PODT window, as described in the following sections.

Creating a Lens

SOLIDWORKS

The parametric lens will be created in a part document. A parametric lens profile can be created in any sketch plane. If you want to create a profile so the light is aimed along the world Z axis, in line with the default lamp model orientation, then create a new sketch in the Top Plane. Once the sketch is created, then some initial geometry needs to be added to define the geometric constraints of the lens. These include the Base profile, Lamp center, and a construction line that defines the 0° aiming angle. You may want to use the sketch origin as the lamp center. The base profile can be any type of open curve. Add a construction line to define the 0° aiming angle. This is often a vertical line anchored to the sketch origin.

Once the input sketch geometry is created, select Photopia > Design Lens and reference the geometry from the sketch in the various input parameters.

Reload - This keeps a reference to lens parameters that have been defined. Most often you only create 1 profile for a given sketch, but if you create multiple then they will be referenced in this list. This drop-down list is most often used to select the parameters to associate with a feature created from the sketch after the profile is completed.

Lamp Center - Select a point that defines the lamp center, the focus of the aiming parameters.

Base profile - Select the curve that defines the base profile.

Prism steps - The minimum number of prism steps along the profile. This value is overridden by the # of aiming sections defined since each aiming section requires at least 1 prism along the profile, so keeping the default value is generally recommended.

Index of refraction - The index of refraction used to determine all prism/curvature computations based on the aiming parameters.

Minimum thickness - Minimum distance between the inner and outer lens profiles.

Edge for 0° aiming angle - Select the construction line that defines the 0° aiming angle, generally the beam center.

Aim by direction / Aim by point - Select the aiming method and define the aiming angles or aiming points.

Target feature - A feature based on this profile does not exist at the start, so leave this reference blank. It will be referenced after the profile is added to the sketch and a feature is created.

Open the PODT window - This button will open the PODT window where you can adjust all lens properties.

Advanced - Non-editable coordinate feedback.

Rhino

A lens profile can be created in any construction plane. The Front View is often used when creating a reflector aligned with the default photometric coordinate system. Once you've selected your construction plane, then draw your Base profile. The base profile can be any type of 2D open curve in this plane. Once the curve is drawn, the select it and click the “Design lens” icon on the Photopia toolbar and follow the command prompts for the input parameters.

Lamp Center - The focus of the lens aiming sections. Often the origin of the construction plane.

Aiming nadir - The direction of the beam center and 0° aiming angle. This is often in line with the -Y direction. Hold down shift and drag your mouse down to indicate a direction straight down.

Prism count - The minimum number of prism steps along the profile. This value is overridden by the # of aiming sections defined since each aiming section requires at least 1 prism along the profile, so keeping the default value is generally recommended.

Index of refraction - The index of refraction used to determine all prism/curvature computations based on the aiming parameters.

Lens minimum thickness target - The minimum distance between the inner and outer lens profiles.

Type of aiming - Enter “D” for Direction or “P” for Point.

Aim by direction / Aim by point - Select the aiming method and define the aiming angles or aiming points.

Aiming start, end & increment - For aim by direction. Enter the desired aiming parameters.

Aiming start, end & aiming section count - For aim by point. Enter the desired aiming parameters.

Choose to open the PODT dialog or skip it. If skipped, the lens profile will be added to the current construction plane. To edit the profile parameters, select the profile and click the “Design lens icon again. This will open the PODT dialog.

Lens PODT Window / Dialog

All the parameters of an optical profile can be viewed and modified in the PODT window.

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Aim by angle - The aiming angles for the start & end of the base profile as well as the angular increment between the 2 extremes. The start and end points refer to the way the profile was drawn. The angles are measured from the nadir direction. Click "Update Aiming" to apply changes.

Aim by point - The start & end aiming point locations within the sketch/construction plane coordinate system, as well as the number of points in between. The start and end points refer to the way the profile was drawn. Click "Update Aiming" to apply changes.

Optical center X/Y - The focus of all refractor aiming sections in the sketch/construction plane coordinate system.

Profile type - Stepped creates a prismatic lens, Smooth creates a smooth lens. The smooth lens profile is anchored at the “start” of the profile. The smooth lens profile is created by connecting the sloped prism faces together, thus removing the riser steps. Since this adds thickness to the lens, be sure to draw the base profile with the appropriate start point based on which end of the lens profile needs to remain anchored in place.

Index of refraction - The index of refraction used to determine all prism/curvature computations based on the aiming parameters.

Number of aiming sections - The number of aiming sections determined by the aim by angle or aim by point parameters. This value can be overridden if you need to add or subtract sections from what the aiming parameters defined.

% control inside - The final refracted light direction results from light refracting into the inner lens surface and out of the outer lens surface. The initial inner and outer profiles are offset versions of the base profile. Prismatic elements are added to the base profile shape on the inner, outer or both surfaces as defined by this parameter. The images below show the effect of this parameter on a smooth lens profile that connects the prismatic elements together. Note that the start of the base profile was on the right side, which is why that point is fixed in all lens variations.

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Number of prisms - The minimum number of prisms or steps along a smooth profile. This value is overridden by the # of aiming sections defined since each aiming section requires at least 1 prism or segment along a smooth profile. Use a value higher than the default to create more prismatic features or a smoother smooth lens profile. As seen in some of the prismatic lens images, the size of the prisms may change along the profile. This is a result of keeping all prisms below an internally determined max height. When a prism is determined to go beyond the max height, it is subdivided into 2 prisms. Setting a higher # of prisms can result in a smoother transition in prism sizes along the profile.

Use pull direction - Enables the adjustment of the prism risers based on the tool pull direction vector & draft angle. This parameter is only used for “stepped” (prismatic) profiles. The angle of the risers is oriented along radial lines back to the lamp center by default. This can result in prisms with undercuts on the inner lens surface as shown in the first image below. This is OK for extruded lenses, but not an injection molded lens. The image on the right shows how the prism riser angles change when a vertical pull direction is used.

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Pull direction X/Y - Defines a direction vector for the pull direction in the sketch/construction plane coordinate system. The image above uses a pull direction X = 0 and Y = 1.

Draft angle - The angle away from the pull direction used to define the prism riser angle.

Peak/Valley fillet radii - The radius of curvature for the fillets used on the peaks & valleys of the prism steps. A value of 0 indicates no fillets will be used, thus all prisms will have sharp peaks & valleys.

Fillet resolution - Fillets are approximated by polyline segments. This parameter defines the angular resolution of the fillet curvature approximation.

Outer/Inner bulge angular extent - Prisms & segments of smooth refractor profiles are flat by default. A “bulge” is an arc shaped curvature added to the flat segment. Bulges create beam spread through each prism/segment. The curvature of a bulge is defined by the angular extent of the arc about the arc center. Thus, the steepest angle away from the flat prism/segment profile is at either end of the arc, with an angle of half the angular extent. See example below that has an angular extent of 40°. For materials with an index near 1.5, light refracts at about half of the profile tilt angle. Therefore, if you want to add 10° of beam spread to either side of the refracted ray directions through your prisms/segments, then enter an angular extent of 40°, 4 times the desired beam spread. The bulge parameters can be defined for the entire optic or individual aiming sections.

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Bulge resolution - Bulge arcs are approximated by polyline segments. This parameter defines the angular resolution of the fillet curvature approximation.

Offset style - The method by which the offset profile is placed. “Simple offset” creates a copy of the base profile perpendicular to the base profile. “Radial from lamp center” creates a scaled version of the base profile along lines from the optical center to the start and end points of the base profile.

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Offset distance - Distance from the base profile start point to the offset profile start point. This is initially set to match the minimum thickness, but may be increased when using a smooth profile and other points along the profile get closer than the minimum thickness to the base profile. Note that this value will not automatically change to find smallest value that meets the minimum thickness requirement as design changes are made. To find the smallest allowable offset distance, enter a value of 0.

Offset direction - Specifies the offset profile direction, to the inside or outside of the base profile.

Minimum thickness - Minimum distance between the inner and outer lens profiles.

Calculate weights - A value of “On” enables the use of the weighting factor (WF) equation.

Weight exponent - Exponent in the WF equation. A higher positive value directs more light toward wider angles. A lower negative value directs more light toward the beam center. A value of 0 sets all WF’s to the minimum value.

Weight minimum - Sets a minimum WF value in the nadir (0°) direction.

Weight shift - Shifts the angle in the cosine function of the WF equation. Useful when your beam is directed toward a surface that is not centered about the nadir direction. For example, when illuminating a vertical wall with a ceiling mounted luminaire, using a weight shift of 90° produces a more trend in the WF’s.

Weight adjustment -Y An adjustment factor that can be applied to the calculated weights for each aiming section.

PODT 3D Surface Creation

SOLIDWORKS

The PODT profiles for reflectors and lenses are created in a 2D sketch. 3D features are then created from these sketches using the standard features available in the SW part file. While any type of 3D feature can be created from the sketch containing the PODT profile, only Extruded Boss/Base and Revolved Boss/Base maintain a connection to the PODT parameters and are interactively updated when changes to the PODT parameters are made. Making changes to these types of features is described in the next section on modifying a design.

Rhino

After creating a PODT reflector or lens in Rhino, a 2D profile is added to the current construction plane. Options to convert the profiles into 3D revolved or extruded surfaces are provided in Photopia’s object properties in the Photopia Settings panel. The properties for all Photopia objects in the model are shown in this panel by default. You can isolate the properties for the PODT object you are modifying by selecting it in the CAD view. You may see 2 sets of properties for a PODT object. The first set, identified with the name of the object, shows the PODT surface properties. The second set shown as "Photopia object settings" includes non-PODT properties.

You can also parameterize other surface types in Rhino beyond the revolved and extruded options provided in the PODT object by using Rhino’s Record History feature. Clicking the Record History button at the bottom of the screen before starting any surface creation tool will create links between the surface and the input geometry. The surface will then automatically be updated whenever you modify the input geometry. The surface maintains Photopia properties such as a material assignment. This allows you to use Photopia PODT profiles as the basis for a much broader range of parametric surfaces such as lofts, sweeps and edge curves. The Record History feature only maintains a single level of parameterization, however. So for example, if you create an extruded surface and later trim that surface, the history will be broken. We have a tutorial for this feature.

Revolved Reflector Surfaces

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Type - The options are Profile, Revolve & Extrude. This drop down is where you change from a 2D profile to one of the 3D surface types.

Name - Any name you prefer to assign to this object.

Lamp center - The world coordinates of the lamp center (not editable). Editing this location is done in the PODT dialog.

Flip orientation - Checking this box flips the default orientation of the surface. The default surface orientation is intended to be correct for the raytrace, but it’s possible the orientation will not always be correct. See advice below for verifying surface orientations.

Start of revolve axis - The revolve axis start point. The revolve axis defaults to a line through the lamp center in line with the aiming nadir, but can be modified to any location and orientation.

End of revolve axis - The revolve axis end point.

Revolve start angle - The start angle of the revolved surface. 0° is in line with the PODT profile. The default is a full rotation through 360°, but the revolved surface can start and stop at any angle to define partially revolved surfaces.

Revolve end angle - The end angle of the revolved surface.

Extruded Reflector Surfaces

Photopia Parametric Optical Design Tools -

Type - The options are Profile, Revolve & Extrude. This drop down is where you change from a 2D profile to one of the 3D surface types.

Name - Any name you prefer to assign to this object.

Lamp center - The world coordinates of the lamp center (not editable). Editing this location is done in the PODT dialog.

Flip orientation - Checking this box flips the default orientation of the extruded surfaces. The default surface orientation is intended to be correct for the raytrace, but it’s possible the orientation will not always be correct. See advice below for verifying surface orientations.

Extrusion Distance - The length of the extrusion away from the profile in a single direction. Values can be positive or negative to extrude in either direction in front or behind the profile location.

Both sides - When checked, this option causes the extrusion distance specified to extend both in front and behind the profile location.

Cap top - Adds and end cap to one end of the extrusion. This is most useful when the extrusion is mirrored as shown in the image above.

Cap bottom - Adds an end cap to the other end of the extrusion.

Flip end cap orientation - Checking this box flips the default orientation of the end cap surfaces. The default surface orientation is intended to be correct for the raytrace, but it’s possible the orientation will not always be correct. See advice below for verifying surface orientations.

Mirror - Mirrors the extruded surface about the mirror plane.

Origin of the mirror plane - The location of the mirror plane. The default is at the lamp center.

Normal of the mirror plane - The normal vector of the mirror plane. The default direction orients the mirror plane to be perpendicular to the reflector profile. The mirror plane can be set to any location and any orientation with these 2 parameters.

Revolved Lens Surfaces

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Type - The options are Profile, Revolve & Extrude. This drop down is where you change from a 2D profile to one of the 3D surface types.

Name - Any name you prefer to assign to this object.

Lamp center - The world coordinates of the lamp center (not editable). Editing this location is done in the PODT dialog.

Close start - When checked, a line segment is included that connects the start point of the base profile to the start point of the offset profile. This line segment is then revolved into a surface unless it is coincident with the revolve axis.

Close end - When checked, a line segment is included that connects the end point of the base profile to the end point of the offset profile. This line segment is then revolved into a surface unless it is coincident with the revolve axis.

Sides that are active - This option allows you to specify which surfaces are included in your model. The options are both, outside only & inside only. This is useful when other surfaces in your model will be used as part of the lens.

Flip orientation - Checking this box flips the default orientation of the surface. The default surface orientation is intended to be correct for the raytrace, but it’s possible the orientation will not always be correct. See advice below for verifying surface orientations.

Start of revolve axis - The revolve axis start point. The revolve axis defaults to a line through the lamp center in line with the aiming nadir, but can be modified to any location and orientation.

End of revolve axis - The revolve axis end point.

Revolve start angle - The start angle of the revolved surface. 0° is in line with the PODT profile. The default is a full rotation through 360°, but the revolved surface can start and stop at any angle to define partially revolved surfaces.

Revolve end angle - The end angle of the revolved surface.

Extruded Lens Surfaces

Photopia Parametric Optical Design Tools -

Type - The options are Profile, Revolve & Extrude. This drop down is where you change from a 2D profile to one of the 3D surface types.

Name - Any name you prefer to assign to this object.

Lamp center - The world coordinates of the lamp center (not editable). Editing this location is done in the PODT dialog.

Flip orientation - Checking this box flips the default orientation of the extruded surfaces. The default surface orientation is intended to be correct for the raytrace, but it’s possible the orientation will not always be correct. See advice below for verifying surface orientations.

Close start - When checked, a line segment is included that connects the start point of the base profile to the start point of the offset profile. This line segment is then extruded into a surface unless it is coincident with the mirror plane.

Close end - When checked, a line segment is included that connects the end point of the base profile to the end point of the offset profile. This line segment is then extruded into a surface unless it is coincident with the mirror plane.

Sides that are active - This option allows you to specify which surfaces are included in your model. The options are both, outside only & inside only. This is useful when other surfaces in your model will be used as part of the lens.

Extrusion distance - The length of the extrusion away from the profile in a single direction. Values can be positive or negative to extrude in either direction in front or behind the profile location.

Both sides - When checked, this option causes the extrusion distance specified to extend both in front and behind the profile location.

Cap top - Adds and end cap to one end of the extrusion. This is most useful when the extrusion is mirrored as shown in the image above.

Cap bottom - Adds an end cap to the other end of the extrusion.

Flip end cap orientation - Checking this box flips the default orientation of the end cap surfaces. The default surface orientation is intended to be correct for the raytrace, but it’s possible the orientation will not always be correct. See advice below for verifying surface orientations.

Mirror - Mirrors the extruded surface about the mirror plane.

Origin of the mirror plane - The location of the mirror plane. The default is at the lamp center.

Normal of mirror plane - The normal vector of the mirror plane. The default direction orients the mirror plane to be perpendicular to the reflector profile. The mirror plane can be set to any location and any orientation with these 2 parameters.

Surface Orientations

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The 3D surfaces created by Photopia are intended to be properly oriented for the raytracer, but are not guaranteed to always be correct. So it’s best to use Rhino’s "Show Object Direction" tool on the Surface Tools panel with the icon indicated above to confirm the surface orientations. If they are not properly oriented, then use the Flip orientation parameter to reverse their direction. It’s best to use Photopia’s flip orientation parameter so the surface orientation is properly maintained as you change other PODT surface parameters. Reflector surface normals should face toward the lamp. Lens surface normals should face to the outside of the lens geometry.

Modifying a Design

SOLIDWORKS

If you create an Extruded Boss/Base or a Revolved Boss/Base feature from your PODT profile, then you can then select that feature in the FeatureManager, then choose Photopia > Design Reflector/Lens. If this is the first time you are editing this feature, then click the drop-down list under Reload and select the reference to the properties you had previously defined. These properties will now be associated with this feature. You’ll see the feature name referenced under Target Feature. The next time you edit the optical properties of this feature, you can directly click the button to open the PODT window. When finished, close the PODT window, then click the check on the PropertyManager page. The profile will be regenerated in the sketch and the feature will be updated with the new sketch geometry

If you use the PODT profile to create another feature type (surfaces, lofted, swept, etc.) our add-in will not automatically replace the profile in the feature, but you can still generate a new PODT profile and manually replace the reference in your feature.

Rhino

Select the PODT profile or surface in the CAD view. If you want to edit the profile parameters, click on the “Design reflector” or “Design lens” icon. This will open the PODT dialog. Changes will be shown in the CAD view once the dialog is closed.

If you want to change surface parameters, then open the Photopia object properties in the Photopia Settings panel.

Spherical Lens Tool

Photopia supports smooth spherical lens parts when created with the Spherical lens feature. The raytracer will treat the lens geometry as mathematically smooth (not meshed) surfaces. The part definitions support convex, concave, and flat surfaces on each side of the lens, as well as annulus features. Using spherical lens parts allows Photopia to better support a range of applications including luminous images, lasers, LIDAR, machine vision, and basic imaging analyses.

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Create a Spherical Lens

SOLIDWORKS

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Open a new part file and start a new sketch in any plane you prefer. The profile of the lens will be constructed in this sketch plane. Click the “Spherical lens” icon. This part is used solely to define a Photopia spherical lens object and no other features should be added. The lens is defined with the following parameters:

Name -Any name you choose as a description for the lens.

Interface type for each lens surface -Specify convex, concave or plane.

Radius for each lens surface -The radius of curvature of the spherical surface is specified in the part model units.

Annulus for each lens surface -The width of a flat flange feature on the lens. This can be unique on each side of the lens.

Cylinder diameter -The overall lens diameter, including the annulus features.

Lens center thickness -The total thickness through the lens center. The value entered will be overridden if any part of the lens gets smaller than the specified minimum thickness. Enter 0 for the lens to be constructed as thin as possible.

Minimum thickness -The minimum thickness of any part of the lens construction. This will be at the outer circumference if the lens is convex on both sides but can be in the lens center if either side is concave.

Rhino

The spherical lens tool is coming soon to Rhino.

Modifying a Spherical Lens

SOLIDWORKS

After a lens is defined, you can modify the lens parameters by selecting the Revolve feature in the part file, then clicking on the “Spherical lens” icon.

Rhino

The spherical lens tool is coming soon to Rhino.

Placing a Spherical Lens

SOLIDWORKS

You can place the spherical lens part just like any other part file using standard mates to any of the solid part geometry or reference planes. The lens part can also be patterned like any other part in an assembly.

Rhino

The spherical lens tool is coming soon to Rhino.

Limitations for Spherical Lenses

SOLIDWORKS

The lens parts are limited to round/revolved shapes and do not support additional features in the same part file.

A single Photopia appearance should be assigned to the entire part as Photopia does not support appearance assignment by face on smooth spherical lens parts.

A single spherical lens part feature is required in a single lens part file.

Rhino

The spherical lens tool is coming soon to Rhino.

Weighting Factors

When the goal of the optical design is to achieve a specific intensity distribution, you need to define both the directions over which the light is aimed as well as the amount of light aimed toward each direction. The aiming parameters defined for reflectors and lenses cover the former. Weighting factors cover the latter.

The weighting factors (WF's) indicate the relative importance/size of each aiming section of the optical profile. The way the WF's work is illustrated in the reflector profile image below. Each reflector section is aimed toward a unique angle in the beam and is assigned a relative WF value. The absolute magnitude of the WF's isn't important, only their relative values with respect to each other. The fraction of the reflector Angular Extent that is allocated toward each aiming section is determined by dividing the WF for that section by the total of all WF's.

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The value of this system is that it allows for quick relative changes to your design by changing a single value. For example, if you need more light at the widest aiming angle, then you simply increase that WF. That aiming section increases in size, while all the rest proportionally shrink. The example above shows higher WF values at the wider aiming angles. These result in a higher fraction of the angular extent allocated to the wider aiming angles.

The rules apply in the same way to lens optics. In their case, the angular extent is the full angle subtended by the Base Profile about the lamp center. The angular extent determined for each aiming section based on their WF's is then projected onto the base profile.

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Weighting Factor Equation

Smoothly changing beams are often required for many applications. These are generally achieved with smoothly changing WF’s, which result in smoothly changing optical profile geometry.

Although WF’s can be entered manually, Photopia provides a WF equation that creates useful trends of smoothly changing WF’s over the entire distribution. For example, if you need to produce even illuminance/irradiance values over a surface below your optic, then you will need an increasing intensity at wider beam angles. This requires WF’s that increase at a user defined rate as a function of the angle away from the beam center. Conversely, if you require a narrower beam optic with the peak in the beam center, fading to a desired beam angle, then you need WF’s that peak at the beam center and decrease at a user defined rate at the wider beam angles. The WF equation has parameters that allow for these types of distributions and more. Understanding the WF equation is important since it allows you to make desired changes to your entire set of WF’s by changing a single parameter of the equation.

The core of the WF equation is:

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Where ϴ is the angle in your intensity distribution. We chose this starting point for the equation since it has the trend of increasing WF’s at wider beam angles, a commonly desired beam trend. The following images show a quick review of the cosine function. It’s the x-component of the radius of a circle as it rotates counter-clockwise from the X-axis. It starts at 1.0 at ϴ=0°, the beam center, and drops to 0 at ϴ=90°.

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So the inverse of the cosine function increases non-linearly as ϴ goes from 0° to 90°. Since the equation divides by 0 at ϴ=90°, the WF value is capped to a maximum of 100.

To add more flexibility to this equation, such as defining the rate at which the WF’s increase at wider angles, an exponent n was added to the cosine function:

Photopia Parametric Optical Design Tools -

As n increases, the WF increases at a faster rate at the wider beam angles, thus more light is directed toward the wider beam angles and less toward the beam center. This results in intensity distributions with trends such as this.

Photopia Parametric Optical Design Tools -

If a negative exponent is entered, then the equation inverts so that the highest WF is at ϴ=0°. Decreasing n to lower negative values causes a greater emphasis of the WF in the beam center. Negative n values create beams with trends like this.

Photopia Parametric Optical Design Tools -

Two more parameters were added to the WF equation that allow you to explicitly define the value at ϴ=0° and rotate the frame of reference when illuminating surfaces that aren’t horizontal below your optic. Some absolute values were also included to avoid negative WF values. The final equation is shown here:

Photopia Parametric Optical Design Tools -

Where:
WF = weighting factor
ϴ = angle in the distribution
n = Weight exponent
Min = Weight minimum (defines the WF at ϴ=0°)
α = Weight shift (angular shift in cosine function)

While it’s best to define your entire set of WF’s with the equation whenever possible, there are times when you need to manually adjust WF’s in specific parts of the beam. Multipliers are therefore provided for each aiming section of your optic.

SOLIDWORKS

Choose Tools > Photopia > General Settings to display the Photopia Settings PropertyManagement page.

Photopia Parametric Optical Design Tools -

Display attributes - All Photopia data associated with the model is stored as attributes. References to these attributes is generally hidden in the FeatureManager but can be viewed by checking this option. Photopia attributes are indicated with a symbol and text describing the type of data, like "PhotopiaSettings". Deleting specific attributes will remove that data from the model, but this should be done only with a clear knowledge of the data being removed.

Recording surface value scaling & gamma - These parameters are generally set in the Recording surface settings PropertyManagement page and may be removed from these options in the future.

Ray visibility - Allows you to indicate the types of rays displayed in the CAD view. Sample rays are standard rays from the ray trace while exception rays are those from any of anomalous interactions.

Ray trace priority - The options are normal, high & aggressive. Using normal will keep your computer most responsive when performing other tasks while a ray trace is running.

Worker count - This defines the # of processor cores that will be used by the ray tracer. Leaving the value at 0 is generally recommended since then Photopia will use the # of cores reported by the operating system. If you know your total # of physical & logical cores, then you can enter that value explicitly or use a value lower than the total to maintain more responsiveness on your computer while running a ray trace. If you have multiple physical processors, then it's best to manually enter the total # of physical & logical cores on both processors here, since Windows generally only reports the total # of cores on a single processor.

Curve resolution - The angular resolution of polyline approximations of arcs used in PODT lens base profiles & fillets.

Global recording smoothing - This parameter is generally set in the Recording surface settings PropertyManagement page and may be removed from these options in the future.

Raytrace engine - A blank value indicates the current ray trace engine is being used. A different version can be entered here if ever required.

Photopia operations version - This relates to a range of functionality for running ray traces and processing output. We recommend keeping this value set to “Current.” If there is ever a need to use an earlier version, then any previously installed version can be selected here.

Optional output - Checking these files will cause them to be automatically written when the raytrace is run. The filenames will share the same name and be written to the same folder as your assembly model.

IES file - The IESNA LM-63 standard format file containing the intensity distribution data. Double clicking on this file will open Photopia Reports, allowing you to view photometric reports and intensity distribution plots. No recorder report data will be available in Reports, however.

Farfield data dump - The far field data dump (*.ffdd) file is an ASCII file that contains the raw data from which the intensity distribution & color data is obtained. The first line in the space delimited file indicates the values in each column. Note that the flux values are always in radiant watts regardless of your lamp flux energy units setting. SPD data will be 0’s when running in tristimulus mode. This data file is useful when performing your own data processing on the far field photometric sphere data.

XML results file - The Raytrace Results Data (*.RRD) file is an XML based file that contains all intensity distribution data, recorder data & raytrace report related data. All formatted reports are created from the data in this file. Double clicking on this file will open Photopia Reports, allowing you to view any reports or plots. This file can also be read by any custom data processing tools built by us or yourself.

Rhino

Choose Tools > Options to display the Rhino Options window and then click on Photopia in the navigation pane.

Photopia Parametric Optical Design Tools -

Defaults - Set the default visibility of recorders, sample rays & the photometric sphere. Each of these items can be toggled on & off via their icons on the Photopia toolbar.

Optional output - Checking these files will cause them to be automatically written when the raytrace is run. The filenames will share the same prefix and be written to the same folder as the Rhino model.

XML results file - The Raytrace Results Data (*.RRD) file is an XML based file that contains all intensity distribution data, recorder data & raytrace report related data. All formatted reports are created from the data in this file. Double clicking on this file will open Photopia Reports, allowing you to view any reports or plots. This file can also be read by any custom data processing tools built by us or yourself.

IES file - The IESNA LM-63 standard format file containing the intensity distribution data. Double clicking on this file will open Photopia Reports, allowing you to view photometric reports and intensity distribution plots. No recorder report data will be available in Reports, however.

LDT file - The EULUMDAT “standard” format photometric file containing the intensity distribution data. Double clicking on this file will open Photopia Reports, allowing you to view photometric reports and intensity plots. No recorder report data will be available in Reports, however.

Farfield data dump - The far field data dump (*.ffdd) file is an ASCII file that contains the raw data from which the intensity distribution & color data is obtained. The first line in the space delimited file indicates the values in each column. Note that the flux values are always in radiant watts regardless of your lamp flux energy units setting. SPD data will be 0’s when running in tristimulus mode. This data file is useful when performing your own data processing on the far field photometric sphere data.

Evaluation results - The raw data available to Photopia’s evaluation system, which is used to test a large range of output values against any requirements you define. The *.evalresults file is XML based and can be read by any custom data processing tools built by us or yourself.

Ray trace priority - The options are normal, high & aggressive. Using normal will keep your computer most responsive when performing other tasks while a ray trace is running.

Worker count - This defines the # of processor cores that will be used by the ray tracer. Leaving the value at 0 is generally recommended since then Photopia will use the # of cores reported by the operating system. If you know your total # of physical & logical cores, then you can enter that value explicitly or use a value lower than the total to maintain more responsiveness on your computer while running a ray trace.If you have multiple physical processors, then it's best to manually enter the total # of physical & logical cores on both processors here, since Windows generally only reports the total # of cores on a single processor.

Engine version - We recommend keeping this value set to “Current.” If there is ever a need to use an earlier version of the ray trace engine, then any previously installed version can be selected here.

Manufacturer - Enter your company name here if you want it specified within the IES file.

Enable expert mode - This option enables extra features in the plug-in interface that generally require a deeper understanding of the software to properly use. Currently, the only extra feature it enables is some additional checks on importing lamp models.

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