4 ms·
If you want to quibble, then in reality, there is only specular light reflection. It’s just that rough surfaces bounce light in many directions because the surf
by Negitivefrags 7y ago
If you want to quibble, then in reality, there is only specular light reflection. It’s just that rough surfaces bounce light in many directions because the surface is rough.
In theory, if you had a high enough resolution texture and used enough samples you could actually represent all materials with only specular reflection.
Diffuse light is simply an approximation we use. We effectively have a value for “roughness” of a surface and assume that some percentage of the lights scatters in all directions using various approximations of how rough surfaces typically reflect light.
So yeah, it’s always “light bouncing off things”
- Jasper_ 7y ago> It’s just that rough surfaces bounce light in many directions because the surface is rough. Sort of, but not entirely, or you would get micro-flares on the surface, which we don't observe in reality. The other half of the equation is light that bounces around inside the object, and then comes out effectively in a random location. The majority of diffuse light is light that has been subsurface scattered. A huge simplification we make is assuming that that light can be modelled with a uniform constant factor, e.g. Lambertian diffuse. For surfaces with with microgeometry larger than the scattering distance, you need a more robust diffuse model, like Oren-Nayar.