Screen Space Shadow Map

[errissa]

I would like to generate an image recording the visibility of the objects in a scene to the emitters in a scene, essentially a screen space shadow map, but I haven't been able to determine if that's even possible with Mitsuba or if perhaps some custom BSDF is necessary. Any ideas?

[njroussel]

Hi @errissa

I have practically no knowledge about screen space shadow maps. If I understood it correctly from your description and a quick google search, you want a direct integrator with the difference that you only want to measure the visibility rather than the radiance.

I assume you still care about how the BSDFs scatter light? If not you would need to replace every material in your scene.

I think the way to do this is a custom Integrator, essentially a copy of direct with a few changes to replace any radiance measures by visibility measures.

I would encourage you to take a look at this tutorial. It might actually be easier to script what you're trying to achieve in a tiny renderer/integrator rather than dealing with some of the Integrator interface complexities.