The Volume Patch operation takes a background volume, a foreground volume, and a mask. It outputs a volume that is exactly the background volume outside of the mask, but fills in the masked region with features from the foreground volume while ensuring a continuous boundary.
The output has the same name as the background group.
This node currently only works with standard Houdini volumes. It does not work with VDBs.
The volume primitive to be used outside of the masked region.
The volume primitives whose features will be used to fill holes in the background.
The volume primitive indicating which regions in the background should be filled in with features from the foreground.
Cutoff for Mask
The operation will apply to regions with a mask value which is at least this value.
Use Foreground as Laplacian
An advanced setting. Instead of filling in the masked region with a volume similar to the second input, fill in the region with a surface that has Laplacian equal to the second input. The Volume Analysis SOP can be used to obtain a Laplacian, which can then be modified and used in this node for more complex fill effects (for example, multiplying the Laplacian by an edge detector creates a terrace effect).