This is a specialized material that adds a coating layer to the geometry. It duplicates the features of Dali Physical.
R (Reflection)
A non-physical parameter that determines the color and intensity of the reflection. To comply with physics, the product of all reflection components must be strictly 1.0 for the entire spectrum. An additional factor, the Fresnel coefficient, will be used in any case.
T (transmission)
This is a physical parameter that determines the shade when the beam passes through the coat. If the Depth parameter is specified, then the Transmission value is the color that the white light will have after traveling the Depth distance.
IOR
Refractive index. Can vary across the spectrum, in which case interesting spectral effects of color dispersion are possible.
Simplified model
Includes the calculation of the simplified model - the model that is implemented in the standard material 3DS MAX Physical Material.
The simplified model is faster.
An exact model is a physically correct simulation of beam re-reflections between dielectric layers. The only assumption is that the coordinates of the entry point and the exit point are the same, i.e. the beam in the dielectric does not actually shift and all texture coordinates remain the same. Only the intensity of the beam is simulated.
Underlying (Simplified model)
In the simplified model, the light passes through the coat, goes into the child material, and returns with some tint. This parameter changes the hue of the child material by interpolating between the returned value and its square. This trick allows you to slightly approximate the results of the simplified model to the results of the exact model.
Depth (for Precision model)
Determines the distance at which white light will acquire the color specified in the Transmission parameter.
Light in a material decays exponentially, and different wavelengths decay at different rates. This parameter sets the "speed" of the decay.
Thickness (for Precise model)
Sets the thickness of the layer. Thickness must be set in the same units as Depth, but not necessarily in units of distance in the scene.
Child material
Child material.
Roughness type
Selects the model that will be used to calculate the Roughness of the material, if any.
GGX and Beckmann models are available.
Roughness
The value of the roughness of the material. 0 - smooth surface, 1 - completely rough. At high roughness values, there is some energy loss and darkening of the result.
Roughness can be varied across the spectrum by setting different values for different wavelengths. This opens up wide possibilities for shading.
Anisotropy
Roughness difference along the U and V axes. Can be changed along the spectrum by setting different values for different wavelengths.
Rotation
Rotation of the U and V axes. Can be changed across the spectrum by setting different values for different wavelengths.
Spectral range
Specifies the interval of the spectrum on which the spectral splines are defined.
