The Volume Rasterize particles operation takes a cloud of points and fills a volume accordingly. If the input volume has more than one named primitive, the named volumes will be filled with data from point attributes that match the name of the volume. Currently only VDB vector volumes support filling from vector point attributes.
The point attributes
density are used to control the
This is a highly specialized node designed for filling the volume as fast as possible, so a lot of the controls present in Volume Rasterize Points are not available.
Filtering is automatically performed to ensure small particles will always contribute to the resulting volume. This means that when you rasterize to a particularly low resolution volume, things will seem to fatten.
volumefilterstochastic integer primitive attribute can be used to
override how points are filtered to voxels. For fields that can’t be
meaningfully averaged together, setting this attribute to a value of 1 on
that volume primitive will cause only one of the overlapping particles to
contribute to each voxel, avoiding any averaging. This parameter only
applies to fields other than density.
This does not support rasterizing into tapered volumes.
Which volumes or VDBs in the first input to stamp into. Each volume or VDB and is treated as a "density" target.
A group of points in the second input to rasterize.
The filter shape that to use when splatting particles. The default gaussian filter will produce smooth blobs and is useful for larger particles. When the particle size is smaller than the voxel size, a box filter will produce a similar result in less time.
density attribute will be scaled by this. If there is no
density, 1 will be used as the reference.
pscale attribute will be scaled by this. If there is no
pscale, 1 will be used as the reference.
Minimum Filter Size
If the particle’s radius is much smaller than a voxel, it can appear to pop from grid-location to grid-location as it moves. This adds an additional blur to particles to ensure they are this fraction of a voxel. A value of 1 ensures the main-support for each particle is at least a voxel, ensuring that any movement of the particle will correspond to a smooth change in voxel values, at the cost of less sharp boundaries.
Enables rasterization of velocity blur. Velocity blurred particles are rasterized by creating multiple point samples along the velocity path and distributing the density of the original point among these samples.
The shutter time to use for velocity blur rasterization.
The shutter offset to use for velocity blur rasterization.
The number of motion blur samples to use for velocity blur rasterization. Larger numbers of samples will produce smoother and more accurate results but will take more time to compute.