| Since | 18.0 |
bsdf ggx(vector ng, vector nn, vector xg, vector yg, vector F0, vector F90, float alphax, float alphay, int masking, int fresblend, float eta, float reflect, float refract, int reflectmask, int refractmask, float dispersion, ...)
Creates a BSDF for computation of the GGX microfacet model, used for rough specular reflection and refraction.
See writing a PBR shader for information on BSDFs.
ng
Normalized geometry normal
nn
Normalized bumped/shading normal
xg
Normalized x tangent vector
yg
Normalized y tangent vector
F0
Color tint at oblique angles
F90
Color tint at grazing angles
alphax
Roughness along the x tangent vector
alphay
Roughness along the y tangent vector (use the same value as alphax for isotropic)
masking
Enable/Disable microfacet masking
fresblend
0 = disable fresnel, 1 = enable fresnel, 2 = use critical angle to select between reflection and refraction.
eta
Index of refraction
reflect
Explicit scalar on reflection (0->1). Or -1 to let the function decide itself on the appriate value based on geometric information.
refract
Explicit scalar on refraction (0->1). Or -1 to let the function decide itself on the appriate value based on geometric information.
reflectmask
Bitmask representing the desired reflection behaviour. Simply passing in bouncemask(reflectlabel) will suffice
refractmask
Bitmask representing the desired refraction behaviour. Simply passing in bouncemask(refractlabel) will suffice
dispersion
Amount of dispersion
Light inclusion/exclusion options ¶
"categories",
string
="*"
Specifies lights to include/exclude by their “category” tags.
This is the preferred include/exclude lights rather than pattern matching
light names with the "lightmask" keyword argument.
For example:
diff = diffuse(nml, "lightmask", "hero | fill");
See light categories for more information.
"lightmask",
string
="*"
When evaluating light and shadow shaders, objects have pre-defined light masks. This mask is usually specified in the geometry object and specifies a list of lights which are used to illuminate a surface or fog shader. It is possible to override the default light mask by specifying a “lightmask” argument.
For example:
diff = diffuse(nml, "lightmask", "light*,^light2");
…will cause all lights whose names begin with “light” except for a light named “light2” to be considered for diffuse illumination.
All Houdini scoping patterns, excepting group expansion, are supported:
-
*- wild-card match -
?- single character match -
^- exclusion operator -
[list]- character list match
| See also | |
| bsdf |
|
| pbr |
|
| shading |
|