The code for the bump mapping implementation is in `src/surfaces/sphere.cpp`, particularly lines 122 to 149 in the `intersect` method.
(##) Microfacet BRDF
Sampling the microfacet normals according to the GGX distribution:
Green is expected / given GGX distribution
x-axis: θ_m, angle between the incident ray and the sampled normal (degrees)
Width parameter of 0.2
Smith shadowing-masking term according to the GGX distribution
Microfaceted material with free Fresnel term (width of 0.2):
Microfaceted gold (width of .1):
Microfaceted copper (width of .1):
Phong vs. microfaceted gold (width of .1):
The code for the microfacet BRDF implementation is located in `src/materials/microfacet.cpp`.
(##) Volumetric path tracing
Visualization of directions sampled from Henyey-Greenstein phase function
Properties of a medium
Pseudocode for heterogeneous vpt
Sampling according to a mixture of each channel's pdf
Cornell box with backlighting through spheres of heterogenuous media, forward and backward scattering
