So… I may be missing something obvious here, but…

I'm having trouble getting multiple VDBs to merge together and form a new, single VDB. The VDB Combine, Volume Merge etc. nodes always merge the VDBs on top of each other. However, in my case, the VDBs are arranged in a grid (they come from multiple point clouds that are in the same grid and together make for a rather large dataset, which I try to avoid handling in a single go).

So, basically I have two VDBs, one at position 0,0,0 and the other at bbox(thefirst's X),0,0. Meaning next to each other. And now I'd love to get a new VDB that fuses them together.

Any ideas? Maybe a Volume Wrangle and copy everything into a large blank VDB?

Michael

Hi Michael
Download the example from openvdb.org
There is a good example in there

http://www.openvdb.org/download/houdini_examples.hip.zip [openvdb.org]

The idea is to merge all vdb:s first then combine it with an empty vdb
Good Luck

Excellent, thanks, I'll give that a go tomorrow!

Some examples are here too:

http://forums.odforce.net/topic/21357-combine-vdb-in-forloop/ [forums.odforce.net]

Thanks!

Though in the end I went and just used combined all the points and made a VDB from that. 125mio particles and Houdini barely broke a sweat

Finally it seems vdb combine actually does what it says on the tin, as of 17.5, with the ‘Flatten all A’ option.

This is how this node should have worked from the start and was one of those things where I couldn't understand why for years it was so convoluted to flatten x number of vdbs!