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• Set your bounding box:  the numbers in [] after "blobbydso:impl_openvdb" is the bounding box for the vdb.  
• Set the path and filename of the vdb after "constant string[2] blobbydso:stringargs". 
• Set the channel name(s). The default channel of your vdb file is not required to be "density".  You just need to rename "density" to the channel in your vdb file.
• If you have more than one channel name, you can append it to the list, e.g. "constant string[2] blobbydso:stringargs" ["$HIP/vdb/smoke.vdb" "density" "velocity"].

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