Houdini 20.0 Nodes Geometry nodes

Volume Rasterize Points geometry node

Converts a point cloud into a volume.

Since 12.5

The Volume Rasterize Points operation takes a cloud of points fills a volume accordingly.

The point attributes, such as pscale, orient, etc, are incorporated to transform the generated noise and displacement fields.

The point attributes padding_absolute and padding_relative will override the per-point computation region.

NOTE: If all you want is a density based stamping, the Volume Rasterize Particles will provide a much faster operation.

Parameters

Destination

Which volumes or VDBs in the first input to stamp into. If no name attribute is present, there should be a single volume or VDB and is treated as the “density” target.

If more than one is present, a name attribute should be present. The name is used to compare with the point attributes.

density will be filled with the alpha mask of the points.

vel will be filled with the local velocity of the points measured both by the v attribute and the angular velocity in the w attribute.

All of the destination must be aligned and of the same type (vdb or volume).

Rasterization Group

A group of points in the second input to rasterize.

Density Scale

A global scale for the evaluated density of the points.

Scale Texture Space

Whether the local texture coordinates for displacement and noise will be scaled by the pscale attribute. Scaling causes the noise pattern to stretch as the particle grows, unscaled means the particle will expand into a fixed noise pattern.

Compositing

Merge Method

How to blend each incoming point in with the base grid. Because it is not defined what order the points will actually be stamped in, this must be symmetric.

Samples per Voxel

If stamping small points a low resolution volume, aliasing artifacts can occur. To avoid this, you can make more than one sample per destination voxel.

If this is 1, no random sampling is done, instead a single sample is done in the middle of the voxel.

Sampling Seed

The seed used for generating the random samples.

Scalar Attrib

An extra float point attribute that will be composited into a same-named volume, provided both exist.

Vector Attrib

An extra vector point attribute that will be composited into a same-named volume, provided both exist.

Integer Attrib

An extra integer point attribute that will be composited into a same-named volume, provided both exist.

Fall Off

Smooth Falloff

The density between the solid core and the outside will fall off linearly if smooth falloff is off. If on, an Elendt model will be used to provide a smoother derivatives at either extreme.

Solid Ratio

The amount of the particle that gets full density. 0 means only the very center of the particle will have full density. 1 means the entire particle out to the pscale will have full density. Note that such a harsh cut off tends to produce aliasing problems.

Exterior Pad

The particles will be expanded uniformly outwards by this distance. This is measured in world space and is thus the same regardless of the particle’s pscale.

Displacement

Enable Displacement

Turns on displacing of each particle’s displacement.

Amplitude

How much to move the surface of the particle. Note this is in world space, not relative space! Making this very large can thus result in unexpectedly long cook times.

Element Size

The size in worldspace of the largest noise pattern.

Element Scale

The noise pattern can be stretched anistropically. The values are in the local texture coordinates of the particle, so will rotate when the particle does.

Animate Displacement

Change the displacement over time.

Pulse Length

Time in seconds for the displacement pattern to fully change.

Noise

Enable Noise

Turns on applying noise to the density. This is used to cut out a pattern of holes through the particle’s splat pattern.

Gain

A contrast adjustment for how extreme the noise affects the density.

Bias

Controls how much of the density will remain after the noise is applied.

Element Size

The size in worldspace of the largest noise pattern.

Element Scale

The noise pattern can be stretched anistropically. The values are in the local texture coordinates of the particle, so will rotate when the particle does.

Animate Noise

Change the noise over time.

Pulse Length

Time in seconds for the noise pattern to fully change.

See also

Geometry nodes