I'm having trouble saving a vdb into the older format. I always get this message in other software when using vdb saved out as .vdb from houdini14 ( I've tried 14.0.233 and 14.0.248):

unsupported VDB file format (expected version 222 or earlier, got version 223)

I've already successfully set the environment variable HOUDINI13_VOLUME_COMPATIBILITY to 1, in bashrc, exporting in the shell, and when in houdini's shell I can successfully echo HOUDINI13_VOLUME_COMPATIBILITY, which returns 1.

I saw a few threads suggesting this workflow, but I didn't see anyone respond that it worked. If it works, maybe something's wrong with my configuration or the way I'm saving it?

If this doesn't work, are there any other options you guys know of to convert the new vdb to an older format? Are there any command line converting tools out there?

Maybe try saving it to BGEO first, then to VDB? Also you could try using the gconvert utility, see if that works.

I have no idea if either of those would work, just throwing darts in the dark

Sounds like a bug to send to support. What OS are you using? Houdini build and/or gcc version (if linux)? Many tools/renderers don't work with OpenVDB 3.0 yet, so the H13 export option should be getting lots of use (at least under certain conditions).

http://forums.odforce.net/topic/22330-vdb-export-from-h14-to-v-ray-problems/ [forums.odforce.net]

same issue and same solution, but it should work when you set HOUDINI13_VOLUME_COMPATIBILITY=1.. :idea: