Houdini 20.0 Nodes Geometry nodes

Guide Advect geometry node

Advects guide points through a velocity volume.

Since 16.5

Parameters

General

Group Type

The type of input group.

Group

A group to use for masking. Any operations will only be applied to the primitives or points within this group.

Blend

Blends the overall effect of the operation.

This parameter can be overridden using an attribute or texture. To do this, select an option from the drop-down menu next to the parameter.

Operation

Constrained Advection

Advect input curves through the velocity field, keeping the points and length of the original curve.

Fill Collision Field

Regrow guide from their roots, constraining motion to collision field. Guides with roots outside of the collision volume are not affected. Advection is stopped when the magnitude of the velocity field is zero.

Fill Velocity Field

Advect guides through the velocity field. Advection is stopped when the magnitude of the velocity field is zero.

Output Group of Affected Primitives

Create a group of guides affects by advection. This includes guides within the input group with blend values above zero and non-zero velocity at the root point.

Output Group

The name of the group of affected guides.

Follow Skin

Makes the velocity field values tangential to the skin VDB in the 3rd input.

Sampling Quality

Controls the advection step size. At 1 the step size equals the voxel diameter of the velocity field.

Segment Mode

Keep Input Segment Count

Output curves with the same point count as the input curves.

Adaptive

Resample curves to a given segment length.

Segment Length

The segment length to use when Segment Mode is set to Adaptive.

Collisions

Stop on Collision

Stop advection when the collision field’s isosurface is hit.

Length

Limit Length

Stop advection when a certain curve length is reached.

Length

The length to stop at.

This parameter can be overridden using an attribute or texture. To do this, select an option from the drop-down menu next to the parameter.

See also

Geometry nodes