- [❔ other question] normalmap and twosided implementation and aov integrators

[guoxx]

Summary

normalmap and twosided not working well with aov integrators. I want to export surface normal for debugging/denoising purpose, however normalmap and twosided is implemented as a bsdf in Mitsuba so that integrator is not aware of it.

IMHO what normalmap/twosided does is actually change the surface intersection properties and that make it different from other bsdfs.

PBRT handle those features in material level, however Mitsuba don't has material and bsdf structure for simplicity so that I think it's better to add BSDF::bump(SurfaceIntersection& its) function for handling those kind of things explicitly, once SurfaceIntersection changed, the integrator can handle it well. Please let me know if there are better way to make it work.