> He did popularize, if not invent the idea of a metalness map.
I don’t know what the precise differences are, but FWIW we had an uber shader that we called “uber shader”, with a metalness map (a texture driven metallic BRDF lobe, not just full color specular) at PDI in the late 1990’s, written by Sing Choong Foo (who worked on the Lafortune model). I’d guess Pixar and other studios had one too by that time.
Thanks for the info, I knew even my statement might have been a stretch.
I'm not even sure Disney can be fully credited with popularizing it, I think it was becoming important in videogames with packed GBuffers almost concurrently.
Re:Raytracing in One Weekend (2016)
by mattkrause on Monday November 30, 2020 @07:54PM
(#25260998)
There is even some crazy work using micro-CT scans to develop highly realistic scattering models of materials. https://www.cs.cornell.edu/~kb/publications/SIG11CT.pdf
A friend worked on a similar project to predict bird (and dinosaur) coloration from the structure of their feathers, which is just wild!
> math formulas created by artists
Rarely do artists create the BSDF, generally a general model BSDF is provided by an engineer or scientest, and the parameterization is tweaked by an artist.
> that specify how light bounces off of objects
Technically a BSDF generalizes all light interaction with medium. a BRDF, is the function that describes how light bounces (reflects, the R in BRDF) off of objects, which is sufficent for raytracing solid, non transparent/translucent objects.
> And an "uber BSDF" that kind of provides sliders for many different objects. (Invented by Disney
The idea of an uber BSDF wasn't "Invented by Disney" Brent Burley did develop Disney's principled BRDF at Disney, but it builds on a long foundation of uber BRDFs at VFX studios. He did popularize, if not invent the idea of a metalness map. It was however already possible to represent metals in existing uber shaders by just using a standard full color specular lobe.
> Understanding the hardware (SIMD-cores, maybe even GPUs)
I'd add understanding memory cache hierarchies, and their affect on performance highest among those.