read_OpenVDB

Reads Bifrost point clouds and volumes from an OpenVDB file. Note that some VDB files may contain multiple volumes with different resolutions and properties, for example, one volume with temperature and another with density. In these cases, the output is an array of volumes – you can use merge_volumes to combine them into a single volume.

Inputs

filename

The file name. Use # to include the input frame number. The number of occurences of # determines the amount of padding. For example, file####.vdb resolves to file0001.vdb, file0002.vdb, and so on.

directory

The directory.

frame

The frame number. You can connect the frame output of a time node to a to_long node, and then connect the result here.

properties

A space-delimited list of properties to read. Use * (asterisk) to specify all properties.

volume_subdivision_structure

The volume subdivision structure of the output Bifrost volume.

adaptivity

When Optimized is selected, will coarsen the read OpenVDB grids to reduce the number of voxels. Note, currently this only does something for level sets. When Off is selected, will read the OpenVDB grids with at least as fine resolution as what is in the file. Currently, VariedFromProperty does the same thing as Off.

max_relative_error

The maximum difference relative to the voxel size and bounding box (for signed distance volumes) that is allowed in the output, compared to the input VDB volume, when adaptivity is set to Optimized. Start by trying the default value, and then adjusting up or down from there based on the result. If the error threshold is too low, artifacts may appear when zooming in, and if the error threshold is set too high there will be less memory and computational savings.

rename_properties

Rename properties to conform to Bifrost naming standards. Note, this only applies to non-Bifrost OpenVDB volumes.

Outputs

points

The output Bifrost point clouds.

volumes

The output Bifrost volumes.

success

Boolean indicating whether the operation was successful.