ParticleFieldOpacityAttributeAPI

Defines an applied schema for ParticleField opacity data.

The opacity should be in the range [0, 1], and treated as traditional (linear) computer graphics opacity, not as transformed data sometimes seen in PLY files associated with Gaussian splats, where the values need to be processed with a sigmoid activation function.

Attributes are provided in both float and half types for easy data footprint affordance. Data consumers should prefer the float version if available.

The length of this attribute is expected to match the length of any provided position data (via any ParticleFieldPositionBaseAPI derived schema). If it is too long it will be truncated to the number of particles defined by the position data. If it is too short it will be ignored. If it is ignored or not populated, then the default value of fully opaque (1.0) is used.

Properties

opacities

USD type: float[]

Defines the linear [0,1] opacity for each particle, in float precision. The length of this attribute is expected to match the length of any provided position data for the ParticleField. If it is too long it will be truncated to the number of particles defined by the position data. If it is too short it will be ignored.

opacitiesh

USD type: half[]

Defines the linear [0,1] opacity for each particle, in half precision. If the float version (opacities) is defined, that version should be preferred. The length of this attribute is expected to match the length of any provided position data for the ParticleField. If it is too long it will be truncated to the number of particles defined by the position data. If it is too short it will be ignored.