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

Note

This node does not filter the results. If you change the resolution you may get aliasing artifacts.

## Parameters

Group

The name(s) of the VDB volume primitives in the input to be re-sampled. See specifying volumes.

Reference VDB

If the second input is connected, you can enter the name of a VDB primitive in the second input to copy the orientation and voxel size from it.

See specifying volumes.

Interpolation Order

How to interpolate positions.

Nearest neighbor

Choose the value from the nearest voxel. This is fast but can cause aliasing artifacts.

Tri-linear

Matches what Volume Mix and volumesample do.

Tri-quadratic

Smoother than tri-linear, but slower.

Define Transform

How to generate the new VDB’s transform.

Explicitly

Use the values in the transform parameters below.

To Match Reference VDB

Use the transform and voxel size from a VDB in this node’s second input. The result is a copy of the first input, aligned to the second input.

Using Voxel Size Only

Keep the transform of the input VDB, only changing the voxel size. This is useful for increasing or decreasing the resolution.

This will result in an aliased grid since no filtering is done.

Using Voxel Scale Only

Same as "Using Voxel Size Only" except that the new voxel size is specified as a scale factor.

Transform Order

When **Define transform** is "Explicitly", the order of operations for the new transform.

Rotate Order

When **Define transform** is "Explicitly", the order of rotations for the new transform.

Translate

When **Define transform** is "Explicitly", the position for the new transform.

Rotate

When **Define transform** is "Explicitly", the rotation for the new transform.

Scale

When **Define transform** is "Explicitly", the scale for the new transform.

Pivot

When **Define transform** is "Explicitly", the pivot point for the new transform.

Voxel Size

The size of voxels in the new VDB. Larger voxels correspond to lower resolution.

Note

This parameter is only visible when **Define transform** is **Using voxel size only**.

Voxel Scale

The amount by which to scale the voxel size in the new VDB. Larger voxels correspond to lower resolution.

Note

This parameter is only visible when **Define transform** is **Using voxel scale only**.

Transform Vectors

When **Define transform** is "Explicitly", apply the transform to the voxel
values of vector-valued VDBs according to its Vector Type.

Rebuild SDF

Transforming (especially scaling) a SDF might invalidate signed distances, necessitating its reconstruction. This option affects only SDF volumes, and it should almost always be enabled for those cases.

Prune Tolerance

Remove voxels within this distance of the VDB primitive’s "background" (empty) value. This is necessary since the resampling can create active but "empty" voxels.

In general, you should leave this option on. Expert users may want to turn this off based on very specific situations. For example, if you know that pruning empty voxels is a waste of time since a later operation will reactivate many of them.

See also |