Optimizing Atmospherics a hundred times

[vfx_film_televsion]

Hello Chaos-Group members,

I have a question regarding VDB and the steps before rendering starts in maya. I exported some clouds from houdini as vdb, each of them is around 2-5 mb.
I did some instancing via the particle instancer. Then I needed to switch the render Mode to Volumetric Geoemetry otherwise my Instances wouldn't render. I also activated the Probabilistic Volumes in the Render Settings.Vray now optimizes the atmospherics for each instace before rendering, which takes about 2-5 minutes for 400 instances. Is there any way to bake this optimization or speed it up ?

Kind Regards
Pirmin

[Svetlin.Nikolov]

Hey,

This can be handled by the instancer indeed. Note that there currently is no support for Volume Grids + particle instancer, so you might encounter other unexpected results as well. I hope we can get to this in a couple of months from now.

Cheers!

[vfx_film_televsion]

Ok thanks for your answer. Seems like I encountered a problem with Volume Grids + Instance on our deadline renderfarm which throws the error:

Error: Renderer returned non-zero error code, -1073740791. Check the log for more information.

Is there a recommended way of scattering volume grids in maya ?

[Svetlin.Nikolov]

Would it be possible to send a scene over to Support that can help reproduce the issue?

Thanks!

[Svetlin.Nikolov]

We should also add an option to disable the optimization which would be useful for you in Progressive, and while the instancing is not supported.

Also, "Optimized atmospheric evaluation" is not related to this pre-pass. What the pre-pass you are seeing does is to remove all the empty space from the grid before rendering starts, so in Bucket mode it would render much faster later.

Cheers!

[vfx_film_televsion]

Hello Chaos-Group-Team once again!

I found another way to instance my VRay-Volume-Grid in Maya. I wrote a little mel script which uses the "instance"-command and the transforms them to particles. When I take a look into the Node-Editor, all of my instanced Volume-Grids are based of my original "not-instanced" Volume-Grid. They just have a new Transform-Node with different Scale,Position and Rotation. However when I press Render it optimizes every Grid one by one. I just wanted to know if this could be changed in future releases or is there another efficent way to scatter hundreds or even thousands of Volume-Grids without the need to optimize every single one of them.

[Svetlin.Nikolov]

Hey,

The change is already in the nightlies and will be in the next official release for Maya as well - there is now the option to turn off this pre-process.

Cheers!

[vfx_film_televsion]

Thanks for the quick response!

May I ask when the official release of 3.5 will be? I'm facing a deadline around middle of april and I don't know if I should just try the nightlies build...

[Svetlin.Nikolov]

Not long from now, but unfortunately I can't say exactly.