Houdini 20.0 Nodes Geometry nodes

VDB Morph SDF geometry node

Blends between source and target SDF VDBs.

Since 14.0

The VDB Morph SDF operation will advect a source narrow band signed distance field towards a target narrow band signed distance field.

See volumes for an explanation of standard volumes and OpenVDB volumes.

Parameters

Source

The source VDB primitive to blend. It must be an narrow band signed distance field from the first input.

Target

The target VDB primitive to blend. It must be an narrow band signed distance field from the second input.

Alpha Mask

If enabled, it will use the third input’s VDB for alpha masking. Assumes voxel values are between 0 to 1 inclusive.

Advection

These control how the SDF is moved from the source to the target.

Timestep

Number of seconds of movement to apply to the input points. The default is 1/$FPS (one frame’s worth of time). TIP

This parameter can be animated through time using the $T expression. To control how fast the morphing is done, multiply $T by a scale factor. For example, to animate it twice as fast, use the expression, $T*2.

Spatial Scheme

How accurately the gradients of the signed distance field are computed. The later choices are more accurate but take more time.

Temporal Scheme

How accurately time is evolved within the timestep. Later choices are more accurate but take more time.

Renormalization

After morphing the signed distance field, it will often no longer be a proper signed distance field. A number of renormalizaton passes can be performed to convert it back into a proper field.

Steps

The number of times to renormalize between every substep.

Spatial Scheme

How accurately the gradients of the signed distance field are computed. The later choices are more accurate but take more time.

Temporal Scheme

How accurately time is evolved within the renormalizaton stage. Later choices are more accurate but take more time.

Alpha Mask

Invert Alpha Mask

Inverts the alpha mask so that values from 0-1 maps to 1-0.

Min Mask Cutoff

Alpha mask values below this are mapped to 0.

Max Mask Cutoff

Alpha mask values above this are mapped to 1.

See also

Geometry nodes