In this example, we will demonstrate how to use Speos for an early study of RGB (Red, Green, Blue) ambient lighting. The goal is to evaluate the lighting effect at a given position before going to the development of a lightguide.
[[NOTES:]] Software Prerequisites
To be able to use this example, the following tools and assets need to be installed on your computer:
- Ansys Speos 2022 R2 or later
- Access to an Ansys Speos Premium license
Understand the simulation workflow and key results
In the automotive industry, during the early study and styling phase, the design can change frequently and thus the ambient lighting intent (what is lighted, which effect, …à. For this pre-development phase, it is important to check if the chosen design leads to what was expected or not and mitigate potential disturbing effects such as reflection. In this example, we will use a simple white surface source to have a fast result. We will use spectral filtering on this source to obtain a result in RGB, on which different analyses can be done, for example, disturbing reflection check.
The model to be considered is a car door panel including a nominal lightguide represented by the white surface in the geometry. This surface will be used as support for the Speos surface source, materialized by the rays visible in the pictures below.
Evaluation of the ambient lighting of the door model for red, green and blue lights would typically require three simulations as only one source is allowed on a surface.
A more efficient approach, adopted here, is to use a source with a flat spectrum (100% at all wavelengths) and obtain the response of each colour source through post-processing by filtering the result with red, green and blue spectra.
Source with flat spectrum
The model uses a source with a flat spectrum (100% weighting at all wavelengths) and a spectral sensor with separation by layer set to source.
Run and Results
Instructions for running the model and discussion of key results
Step 1: Speos Simulation using a source with flat spectrum
- Open [[SUV_GENERIC_CAR_DOOR_2022r2.scdocx]] and run the simulation ‘Door’
- Visualize the result [[Door.Normal.xmp]] by double clicking on it in the simulation tree
As expected, we obtain a white source on the surface used in the simulation.
Step 2: Spectral filtering of the source
The objective is to filter the spectral map white source in different colours and save each result.
- Open the Virtual Lighting Controller and then click on the spectrum of the source as shown below.
- In the new window with the current source spectrum, enable ‘Define a new light source spectrum’ and select the new spectrum file. We can first begin with the red spectrum, supplied with the project.
The following shows the result for red:
In the Virtual Lighting Controller, we can rename the source.
- Export this result with File, Export. We then choose a name that includes the color, for example, [[Door.Normal_Red.xmp]]. Note that the “Export filtered data” option should be selected in the Export parameters window.
A new file is created and opened. The source is red. If we go to the Virtual Lighting Controller, we can see that the spectrum cannot be changed.
- Repeat the above steps to create the results for green and blue as well.
- Select ‘Map union (combine maps)’ operation in the “Virtual Photometric Calc” tool. This will combine all the source layers from steps 3 and 4 into a single source file.
The following shows the result from the combined source. The response to different color mixing can be easily obtained by simply changing the weighting for each color.
Important model settings
Description of important objects and settings used in this model
Light source spectrum
The spectrum must be flat (100%) and cover the complete spectrum to filter
- The type of the sensor must be spectral
- The layer must be set to source
Taking the model further
Information and tips for users that want to further customize the model
- We could add an environment source like a uniform or HDRI source to visualize the unlit aspect of the door panel and add this result in the union to have unlit and RGB result in one file. We would obtain this type of result:
- The filtering process can also be scripted
- Assessment of the result with Human Vision tools (Enterprise license required):
Additional documentation, examples and training material
Relevant Speos Ansys Learning Hub (ALH) courses
- Ansys Speos Getting Started
- Ansys Speos Human Vision (Advanced)
- Luminance Matching and Human Vision | Ansys Webinar (Advanced)
Speos user guide
- Speos Labs User's guide - Automation (Help to script Labs operations)
Knowledge Base and App. Gallery articles