I need to simulate the light distribution on a curved surface. I have the surface as an IGES-file and importing it and setting it as a detector works fine. However, I need to sample the irradiance on my surface with ~ 200k pixels. According to the documentation, the only way to change the number of pixels for a CAD detector is by changing the “Chord Tolerance” under the CAD properties. And I can easily go up to 100k pixels with my surface by going down to chord tolerances of about 1E-4. However, if I further decrease the chord tolerances, the number of pixels peaks at 120k at a chord tolerance of 3E-5 and then starts to decrease again. At 1E-5, I am down to only 110 k pixels and at 1E-6 I get only 50k pixels.

I also tried different values for the “Surface Tolerance” under the chord tolerances but this does not seem to have any effect here. What can I do to better sample my light distribution? And why would the number if pixels start to decrease for smaller tolerances in the first place?