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Lecture 14: Material Modeling (18)
chethus

This reminds me of the idea of fractals where each bump has its own roughness and own entire microstructure. I wonder if ideas from studying fractals (e.g. fractal dimension of a material) could be useful for understanding how light interacts with such materials.

AlbertScribblenaut

Could there be cases where there are multiple reflections within the microfacet if it is very steep?

NicholasDrian

I wonder if these micro facets are just a convenient analog for what is actually a wavy electromagnetic field. I wonder if these contours are actually material or if they are on the particle scale.

JefferyYC

I enjoy how this theory elegantly explains the underlying reason for BRDF functions being different for different materials -- their microfacets are distributed differently.

shreyaskompalli

It's interesting to think about how far down we can take the microfacet theory; no surface behaves truly like a macrofacet since there are always imperfections on a surface. Thus, how do we determine the cutoff of when to treat surfaces like micro or macro facets? There must be some cutoff past which the human eye cannot observe reflective differences due to these imperfections, and I wonder how we determine this point.

nobugnohair

I enjoyed reading your comment on how could microfacet theory could be related to waves and fractals. BRDF is an attribute reflecting the texture of the surface in microscale.

ashvindhawan

@shreyaskompalli, I believe the idea is that we continue past the cutoff of the human eye, so that the lighting effect on a macro scale is accurate even if we can't see the perturbations. Would love a second opinion on this though

melodysifry

This theory was super interesting to me, because I never thought about the fact that if you go down to a small enough scale, every microfacet is specular and behaves like a mirror- it's only the combination of these microfacets that make a material rough or bumpy

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