Note that this application requires Speos 2025R2 or higher
Overview
This document provides guidelines on how to access and connect 3M plug-in for reflective polarizer films used for various optical systems such as displays, AR/VR systems or HUD.
It also includes a Speos 2025 R2 project showcasing the use of the 3M reflective polarizer film plug-in.
Introduction
Speos can integrate external analytical models for optical material characterization, allowing companies to develop and connect their own proprietary material models. Using this capability, 3M developed a reflective polarizer model that accurately represents the performance of its film products.
By making this model available to end users, 3M enables engineers to evaluate and optimize optical system performance during the early design phase. This helps reduce the need for physical prototypes, accelerates design iterations, and supports more informed design decisions.
Plugin in Speos
The Surface State Plugin extends the standard material capabilities of Speos by allowing users to define advanced surface behaviors through custom models. It can be used to represent specific optical effects that are not covered by the native material library, enabling more accurate simulation of proprietary coatings, scattering properties, or surface interactions.
For end users, this provides greater flexibility and fidelity when modeling real-world materials, leading to more reliable simulation results and better-informed design decisions early in the development process.
Plugin development requires programming skills in C++ or Python for CPU based model and C++ Cuda skills for GPU based model.
For more information on how to develop a plugin, please visit this section of Speos User Guide Surface State Plugin Overview or this application gallery article Propagating Rays in Speos Surface State Plugin based on Possibility Distribution Function – Ansys Optics.
To use a plugin model as Material Surface property in Speos, you should follow these simple steps:
- Create material
- In surface properties tab, select type “Plug-in”
- In the File section, browse to and select the plugin file (*.sop).
- In the Parameters section, browse to and select the plugin input file (*.txt).
Please note *.txt isn’t mandatory extension for input and it may change depending on the plugin origin.
UV & Texture Mapping in Speos
Among the information carried by each ray and processed by the plug-in are:
- Theta angle: defines the incidence angle of the incoming or outgoing ray relative to the normal surface.
- Phi angle: defines the azimuth angle of the incoming or outgoing ray.
The azimuth angle depends on the orientation of the plug-in surface in the 3D model. To allow users to control this orientation interactively, a UV map must be created, and a texture must be associated with the optical property.
- UV Mapping is used to map a texture onto a geometric entity (surface or body). Among the available parameters, the Rotation setting is particularly important, as it determines the orientation of the plug-in and the 3M reflective polarizer model within the 3D scene.
- The Texture option, available in the optical property definition, links the plug-in to a specific surface geometry and provides the orientation information required by the model.
A detailed step-by-step procedure is provided in the next section of this document. For a general introduction, refer to Texture Mapping Process Overview or to Lumerical Sub-Wavelength Model plugin: Usage in Speos – Ansys Optics
We recommend not to use MOF plug-in with Speos Pro license, as texture and UV map functionalities are available from Premium license.
3M MOF Plugin
MOF stands for Multilayer Optical Films. This is a technology film produced by 3M for various applications such as HUD or displays. 3M Multilayer Optical Films (MOFs) contain hundreds of layers of birefringent optical material with each layer having a thickness on the order of a hundred nanometers. Through constructive and destructive interference these layers are used to create mirrors (3M™ Enhanced Specular Reflector Film (ESR)), reflective polarizers (3M™ Advanced Polarizing Film, 3M™ Image Quality Polarizer (IQP), etc.), and other 3M products.
Models for display and consumer electronics are already freely available. For automotive models are currently not published publicly, but it doesn't mean there is nothing available.
If a product you need is not listed, please use the DMH support center to request it.
On DMH, material models and their input files are stored in separate locations. As a result, both must be downloaded independently: one download for the material model and another for its associated input file.
Material models use the .sop file extension, while input files use the .sdf extension, which stands for Structured Data File. This file format is widely used in the chemistry industry because it can store both molecular structure information and its associated metadata.
3M DMH provides several *.sdf file variants corresponding to different medium combinations. You can therefore select the file that best matches your model configuration. The *.sop files and their associated *.sdf files are fully compatible with the Reverse Normal functionality in Speos.
3M Digital Material Hub (DMH)
The 3M Digital Materials Hub is an online platform that provides access to verified 3M material data, simulation models, and product specifications. It enables users to quickly evaluate, compare, and download digital material models for use in design and simulation workflows.
How to access data on 3M DMH:
- Connect to the platform by clicking on “Login/Register”
- If not done before, DMH allows you to create an account.
- Once connected, you access the DMH main page, where 3M summarizes all their materials and modeling packages:
- Access to model inputs:
- Click on “Products with Optical Models”
- For this example, select “3M™ Standard Reflective Polarizer (SRPi)”
- On the top right corner of the webpage, click on “Download model”
- Select the medium combination.
- For this example, please select Optical OCA*/Air.
* OCA: Optical Clear Adhesive
Note: The zip file is about 2.2Gb. Once unzipped, the folder is about 4Gb.
The folder contains the following items:
| File name | Usage |
| 3M OCA.material | Speos base VOP material |
| OCA_SRP-NIR_Air.SDF | SOP Plug-in input |
| OCA_SRP-NIR_Air_CF.SDF | SOP Plug-in input (Fourier Interpolation Files) * |
| OCA_SRP-VISIBLE_Air.SDF | SOP Plug-in input |
| OCA_SRP-VISIBLE_Air_CF.SDF | SOP Plug-in input (Fourier Interpolation Files) * |
| 3M OCA.mat | Not used in Speos |
* For more information, go to DMH > Learning center > How are the Optical models delivered > Optical Model Data Package.
- Access to model:
- Click on “Learning Center”
- Click on “Optical Models”
- Scroll down and download “3M Virtual Sample Interface for Speos Setup”
- Once downloaded and extracted, you will find an executable (.exe) file. Running this file will decompress the model to a location of your choice.
- Once decompressed, you will get the following files:
| File name | Usage |
| emll_speos.sop | 3M Plug-in to import in Speos |
| EULA for 3M Virtual Sample Interface SPEOS.pdf | License agreement |
| unins000.dat | Used for uninstallation |
| unins000.exe | User for uninstallation |
The *.sop plug-in file can be then displaced by a copy past everywhere you want. The location used to decompress the model doesn’t have any impact with the usage of *.sop file in Speos.
Example - Sun Burn and Virtual Image Analyses
Data model presentation
This article introduces an example dataset to illustrate the use of the 3M™ Cold Mirror Film (CMF). The image above provides a 3D view of the system together with descriptions of the main components for reference.
In this configuration, the CMF model is applied to the reflective surface of the Fold Mirror.
The dataset supports two analyses:
- Sun Burn Analysis: Assess the amount of energy reaching the extracted housing surface and the PGU.
- Virtual Image Rendering: Generate and evaluate a virtual image with the 3M polarizer applied.
To quantify the impact of the 3M model, both analyses can be performed and compared against a reference HUD configuration using a standard mirror surface. The Speos model has been preconfigured and is ready for simulation.
The following sections describe the procedure for configuring the 3M polarized film model plug-in.
Model preparation
The Speos model attached to this article is provided in a ready-to-run state. Only the 3M CMF model needs to be requested through DMH. This request can be submitted via the Support Center by following these steps:
- In DMH, navigate to the Support Center tab.
- Click the Request Support button.
- Select Request Model under Support Type.
- Select 3M™ Cold Mirror Film (CMF) under 3M Product Name.
- Choose the appropriate Preferred Model Type according to your study requirements. For this example, the film is attached to the rest of the system so Air/OCA is preferred.
You may also provide a short description of your project and an estimated project value.
After submission, 3M will review your request and provide a response. Please note that some processing time may be required before you receive an answer.
Once you have obtained the model from 3M, you will have everything needed to proceed with the remainder of this article.
- Download Speos model “START.zip” attached to this article and unzip it.
- Open the project in Speos and configure the material:
- Go to the Simulation tab.
- Expand Materials > 3M_CMF.
- Open the Surface Layer settings.
- Import the 3M_MOF_Plugin.sop file from the File tab.
- Import the corresponding OCA817X_CMF.SDF file from the Parameters tab.
The model is then ready for analysis and rendering.
- Open and edit “M1_OCA”
- In file, import “3M OCA817X.material”
Note: We also recommend to explore other Speos items defined in the model. Especially the UV map definition, which is mandatory for 3M plug-in usage (see the Speos User Guide: Texture Mapping Process Overview)
3M also provides a guide to help you quickly set up the plug-in from scratch
Plus, you can find all the necessary knowledge in this user guide section: Texture Mapping Process Overview
Sun burn analysis
In Speos simulation node, there is a Sun Burn folder with two simulations:
These two simulations are same except that the optical property used on the fold mirror: the first one is using a 100% reflective mirror, and the second one is using the 3M CMF plug-in.
Both simulations are ready to be launched. We recommend you launch both simulations with CPU as for now, 3M plug-in is only compatible with CPU computation.
Once simulations are done, you should get *.xm3 file per simulation.
The sensor used in the simulations is a 3D irradiance sensor covering the surface in front of the PGU source (surface 2 on picture below), and a surface, behind the fold mirror, mimicking HUD cavity enclosure (surface 1 on picture below).
After running the two Sun Burn simulations, you should obtain results similar to those shown above. Two surfaces should be displayed:
- Surface 1 corresponds to the extracted HUD cavity enclosure. This surface receives the solar flux originating from sunlight outside the visible wavelength range.
- Surface 2 corresponds to the polarizer surface, defined as the last surface of the PGU. For the purpose of this analysis, this surface is also considered the PGU entrance surface.
Virtual 3D irradiance Viewer (XM3 Viewer) allows you to make measurement thanks to a grid projection on surfaces. To position a measurement area, you should manipulate the axis system displayed in the viewer 3D view. We recommend you rely on point click plus shift key to position your measurement area in the 3D space of the XM3 Viewer. You can find more info about this topic here.
The results obtained on these two surfaces can be exported and used as inputs for subsequent thermal and structural mechanical analyses. These studies help assess the impact of solar loading and identify potential degradation risks affecting either the cavity enclosure itself or components located within the PGU.
Note: Results of this simulation are not here to demonstrate the performance of 3M CMF model but simply illustrate type of results you could get in context of sun burn analysis. More specifically, it also shows you that your model would become more accurate as 3M CMF model considers more information and details compared to a simple material model such as pure reflective surface.
Virtual Image simulation
In Speos simulation node, there is a VI (for Virtual Image) folder with two simulations:
Same as previous section, these two simulations are same except one is using a fold mirror with a 100% reflective and opaque mirror, and the other one uses fold mirror with 3M CMF plug-in. They also share the same radiance sensor. Goal here is to showcase how 3M plug-in can affect the performance of your virtual HUD system, on several meaningful simulation types.
Going further
Since the primary purpose of the 3M CMF is to protect the PGU from solar damage, it can be highly beneficial to complement the optical analysis with a thermal assessment.
To support this type of multiphysics workflow, Speos can be coupled with Ansys Mechanical and Ansys Thermal through System Coupling. This platform enables seamless data transfer between Speos and other Ansys solvers, including Mechanical, Thermal, Fluent, and additional simulation tools. As a result, different physical phenomena can be linked together in the sequence that best suits the analysis.
For example, the results of an optical simulation can be used as input for a thermal analysis, whose output can then serve as input for a structural deformation study. This approach allows engineers to evaluate how solar loading affects component temperature and mechanical behavior.
Depending on the component under investigation, such as a mirror or another optical element exposed to solar radiation, the workflow can be extended by feeding the thermally and structurally deformed geometry back into an optical simulation. This closed-loop approach makes it possible to assess the impact of thermal and mechanical deformation on the overall optical performance of the system.
An example can be shared on demand if you are interested in investigating this aspect.
Additional resources
Additional documentation, examples and training material