Hi Troops
Just playing around with H15+, really nice work SideFX.
I wanted to make some smoke and render it in Modo 10 with Octane 3 but I'm hitting a blank wall.
I see the files being written in my VDB folder but nothing shows up in Modo's viewport.

Is it an Apprentice thing, do I need to purchase Indie?

Please point me in the direction of victory!!!

Thanks in advance
Josh

Moin, Josh,

I didn't see this thread, so maybe you won't even read my response - but anyway:

My guess is that it's modo that isn't behaving for you. VDB in modo seems to be always flaky or outright broken and I didn't get the impression (when I was using modo) that showstopping bugs were considered important to fix.
A colleague who uses modo 9 told me that VDB import in the last release of modo 9 is basically unusable. So I tried modo 901 sp1, which he said would sometimes work. Unfortunately it constantly crashed on me trying to do *anything* with VDB. By that I mean: It did not work *AT* *ALL*.
Obviously I won't even try modo 10 (I did once and it crashed on too many occasions, so I uninstalled it after about 30 minutes), because leaving a product in a fundamentally broken state and then forcing users to pay for an upgrade is a business practise I do not support.

What you *can* try is: Force Houdini to not pack VDBs by putting a line
into your Houdini.env file. My colleague said that this would sometimes let modo 9 read VDB data (if it doesn't crash, which is far more likely). Like I said, modo 902spwhatever didn't do anything with VDB for her or me, so it's possible that modo 10 has the same VDB issues.

However, Octane works with Houdini (Indie and up), so maybe this is an alternative for you - just bypassing the probable cause of frustration in the pipeline alltogether?

Marc

Hi Marc
Thanks for taking the time to write about your experiences with Modo and VDB's.
I've totally cut Modo out of the picture to render vdb's from Houdini, it's simply broken.
I have a demo of C4D R18 and a proper licence of Octane for it. I got them rendering in no time at all, ever so simple.

Thanks again to SideFX for offering a version of Houdini that people can cut their teeth on, that's really generous.


Cheers
Josh

Hi, Josh,

out of fairness towards modo: I managed to get VDB data from Houdini over to modo 902 (901 crashes while trying anything there). The ENV-variable (H13-compability) mentioned above did the trick, interestingly I had to rebuild the Houdini file. It seems that simply setting the variable and loading the previously created file did not work, but rebuilding the export (convert Houdini volume to VDB, then write out to a file) worked.

In modo I was able to get “something”, but any visually usable volume renders would take incredible long amounts of time. So this is really just trying to be fair to a platform I used to really love.

Marc

A bit more background about why you have to write out files again after setting HOUDINI13_VOLUME_COMPATIBILITY, for anyone curious. That flag switches the version of OpenvDB being used write files back to OpenvDB 2.0/2.2, which is what H13 was using. There are several software vendors still using older 2.x versions of OpenVDB libraries, for whatever reason, whereas most are using OpenVDB 3.x (4.0 was released a few months ago).

The reason this matters, is the OpenVDB devs keep the underlying grid format compatible within a major release; so 2.0, 2.1, 2.2, etc… are intended to be able to read/write the VDB files interchangeably, even if 2.2 might have tools/filters not available in 2.0. It's only major versions that aren't ABI compatible (i.e. files saved in 3.x can't be read by 2.x). When you turn on HOUDINI13_VOLUME_COMPATIBILITY, that saves the vdb files in OpenVDB 2.x format, whereas by default the version being using is OpenVDB 3.x.

If you're curious about which version of OpenVDB Houdini is using, or any other third party library, check out the licenses page for that verison:

• Houdini 13.0 [sidefx.com]
  
• Houdini 14.0 [sidefx.com]
  
• Houdini 15.5 [sidefx.com] (uses OpenVDB 3.1 same as 15.0)
  

Thanks for replying.
I have posted what you said on the Modo forums. It's a topic of great discussion at the moment and I have even got the developers in on the action.
Basically they said Blosc decoding is working within Modo but has a few issues that will be corrected before the next release.

Cheers troops
Thank you.
Josh

Thanks Mal and Josh. I just dived into Houdini coming from Modo so it's nice to see familiar names. I am running into issues with modo slowing to a crawl with lots of geo or dynamics going on. Kudos to SideFX as well for having a version we can learn on a license later.

Look forward to some volumetric clouds that will render in under 5 months

I'm still waiting for them to do the bug fixes I reported on the whole VDB importer thing. It works, but not very well. They have moved the goal to Modo 11.1 now.