Houdini 20.0 Nodes Geometry nodes

VDB Smooth geometry node

Smooths out the values in a VDB volume primitive.

Since 12.5

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

For each voxel, this node computes an average (see the Operation parameter) from the surrounding values and sets the voxel to that average. (The “surrounding area” is a cube, despite the name Filter Voxel Radius).


To smooth an SDF, use VDB Smooth SDF.



The name of VDB primitive(s) in the input to be smoothed. See specifying volumes.

Alpha Mask

If enabled, it will use the second input’s VDB for alpha masking. Assumes voxel values are between 0 to 1 inclusive. See specifying volumes for more information.


How to smooth the voxel values.

Mean Value

Find the mean (total/count) of the surrounding values. This is equivalent to a box blur of the same radius.

Median Value

Find the median (middle value) of the surrounding values. This is useful for de-spiking noisy data as extreme values will not contribute to the final result.

Filter Voxel Radius

The number of voxels to run the smooth operation over. This is measured in voxels, not distance. This distance defines a cube, so increasing the “radius” will exponentially increase the work.


Number of times to repeat the smoothing operation.

For a cone blur, multiply the radius by 0.454545 and use two passes. For a gaussian, multiply the radius by 0.33 and use four passes.

Renorm Accuracy

The method for smoothing the SDF after each iteration. Later options in the list are slower but more accurate.

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