The VDB Diagonistics node has a suite of tests to validate and correct common errors in VDB nodes. For most errors, it provides an option of marking the troublesome voxels and/or repairing them.
Which input VDBs to examine.
Mark in Mask Grid
For tests set to Mark, output a mask VDB that highlights problematic regions in input VDBs.
Mark as Points With Values
For tests set to Mark, output a point cloud that highlights problematic regions in input VDBs.
Respect Grid Class
If disabled, apply fog volume and level set tests to all VDBs, not just VDBs classified as fog volumes or level sets.
Validate Fog Volumes
Verify that VDBs classified as fog volumes are valid fog volumes.
Validate for SDF CSG and Fracture
Verify that SDF VDBs meet the requirements for CSG and fracture operations.
Validate for SDF Filtering and Renormalization
Verify that SDF VDBs meet the requirements for filtering and renormalization.
Validate for SDF Advection and Morphing
Verify that SDF VDBs meet the requirements for advection and morphing.
Verify that all values are finite and non-NaN.
Verify that all inactive voxels are set to the background value.
Values in Range
Verify that all scalar voxel values and vector magnitudes are in the given range.
Minimum and maximum allowed values (inclusive)
Symmetric Narrow Band
Verify that SDF inside and outside values are of equal magnitude.
Minimum Band Width
Verify that interior and exterior narrow band widths are sufficiently large.
Verify that SDFs represent watertight surfaces.
Verify that the SDF gradient has magnitude one everywhere (within a given tolerance).
Verify that SDFs have no active tiles. These would represent constant regions that should not occur in an SDF.
Uniform Voxel Size
Verify that SDFs have uniform voxel sizes.
Verify that all inactive voxels in fog volumes have value zero.