Shaders

Physical Scatter

This shader performs three kinds of simulations which can be used together or independently:

Multiple-scattering estimation
the most accurate, uses a strictly deterministic simulation of photon tracing to record sites in an internal photon map. These sites are looked up at render time and an optimized ray marching technique estimates multiple scatter irradiance.
Single-scattering approximation
is based on light intensities, independent of photon mapping.
Diffusion theory
is applied to evaluate the contribution of photons in the deep layer.

The following scattering features are supported:

misss_physical
color "misss_physical" (
    color           "material",
    color           "transmission",
    scalar          "ior",
    vector          "absorption_coeff",
    vector          "scattering_coeff",     
    scalar          "scale_conversion",
    scalar          "scattering_anisotropy",
    scalar          "depth",
    integer         "max_samples",
    integer         "max_photons",
    scalar          "max_radius",
    boolean         "approx_diffusion",
    boolean         "approx_single_scatter",
    boolean         "approx_multiple_scatter",
    array light     "lights",
    integer         "mode")

The shader provides parameters for Optical Properties and Tuning. The shader has to be applied both as a material and a photon shader.

misss_physical_phen
material "misss_physical_phen" (
    color           "material",
    color           "transmission",
    scalar          "ior",
    vector          "absorption_coeff",
    vector          "scattering_coeff",
    scalar          "scale_conversion",
    scalar          "scattering_anisotropy",
    scalar          "depth",
    integer         "max_samples",
    integer         "max_photons",
    scalar          "max_radius",
    boolean         "approx_diffusion",
    boolean         "approx_single_scatter",
    boolean         "approx_multiple_scatter",
    array light     "lights",
    integer         "mode"
    )
version 4
This is a material Phenomenon with appropriate shader connections both to the material and photon slots. Its parameters and behavior are identical to misss_physical.

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