BaseVolume
Overview
BaseVolume is a volume shader meant to be applied to a water tight mesh. The volume is homogenous by default but can be made heterogenous by binding maps to any of the attributes. Map bindings are evaluated and baked into the grid based on the bake_resolution_mode.
Attribute Reference
Volume attributes
anisotropy
Float bindable
default: 0.0
Value in the interval [-1,1] that defines how foward (1) or backward (-1) scattering the volume is. A value of 0.0 indicates an isotropic volume.
attenuation_color
Rgb bindable
default: [ 1, 1, 1 ]
A color multiplier for the attenuation. The resulting color will be the inverse of the color set with this parameter.
attenuation_factor
Float bindable
default: 1.0
An additional factor to scale the attenuation. This attribute behaves identically to attenuation_intensity - it is provided simply as an extra way to control attenuation, typically during lighting. Surfacing should generally avoid setting this.
attenuation_intensity
Float bindable
default: 1.0
The rate at which the intensity of a ray traversing a volume is lost. The attenuation (extinction) coefficient is the product of attenuation_color, attenuation_intensity, and attenuation_factor
diffuse_color
Rgb bindable
default: [ 1, 1, 1 ]
Reflectance color (scattering albedo) of the volume.
emission_color
Rgb bindable
default: [ 0, 0, 0 ]
A color multiplier for the emission. The product of emission color and intensity is the emission coefficient
emission_intensity
Float bindable
default: 1.0
The rate at which a volume emits light at a given point. The product of emission color and intensity is the emission coefficient.
surface_opacity_threshold
Float
default: 0.5
Accumulated opacity that's considered the 'surface' for computing surface position and Z
Volume Baking attributes
bake_divisions
Int
default: 100
Divide widest axis by this many divisions
bake_resolution_mode
Int enum
0 = “default” (default)
1 = “divisions”
2 = “voxel size”
Method to specify grid resolution of baked density grid. Choices are:
"default": For shaders that are bound to vdb volumes, use vdb resolution.
For shaders that are bounds to mesh geometries use 100 divisions
"divisions": Specify number of divisions.
"voxel size": Specify voxel size.
bake_voxel_size
Float
default: 10.0
Size of voxel in world space
General attributes
label
String
default:
label used in light aovs