The VDB Convert operator can be used to convert SDF voxels to scalar voxels and vice versa.
SDF to scalar: converts an SDF grid to a scalar grid. Scalar grid values will correspond to SDF distance values (scalar values will be higher for cells closer to SDF surface).
Scalar to SDF: converts a scalar grid to an SDF grid by constructing an implicit mesh from the scalar grid and deriving an SDF from the mesh.
Rebuild SDF: rebuilds an SDF grid by constructing an implicit surface from the SDF and then re-calculating the SDF values for each cell in the grid based on their distance to the surface.
SDF/Scalar grid name: the names of the source VDB grids.
Iso value: controls the iso value for scalar grid conversion. Higher values bias the surface level towards higher scalar values.
Keep grid sparse: when enabled, simplified voxel groups in the VDB tree will not be broken up into individual voxels.
“Keep grid sparse” can reduce memory usage, but if voxels values are significantly changed in some way (ex: displaced), large square artifacts can appear in the grid.