Matte材质及其对应的反射模型：

设置材质和反射模型是在材质对象的ComputeScatteringFunctions()成员方法中。
下方是Matte材质的ComputeScatteringFunctions()成员方法的截图：

调用该方法的callstack截图如下：

其他材质及其对应的反射模型：

MatteMaterial
Kd, a spectral diffuse reflection value
sigma, a scalar roughness value. 0 — LambertianReflection; otherwise — OrenNayar
bumpMap, compute a shading normal at each point

PlasticMaterial
Kd, LambertianReflection
Ks, MicrofacetReflection
roughness
bumpMap

MixMaterial
combine two Materials, ScaledBxDF

FourierMaterial
bsdfTable, FourierBSDF

GlassMaterial
SpecularReflection, MicrofacetReflection
SpecularTransimission, MicrofacetTransmission

MetalMaterial
MicrofacetReflection

MirrorMaterial
SpecularReflection

SubsurfaceMaterial
SpecularReflection, MicrofacetReflection
SpecularTransimission, MicrofacetTransmission

TranslucentMaterial
LambertianReflection, MicrofacetReflection
LambertianTransimission, MicrofacetTransmission

UberMaterial
SpecularTransmission, LambertianReflection,
MicrofacetReflection, SpecularReflection, SpecularTransmission