Vray doesn't evaluate expressions during batch rendering

[ojk]

Hi guys!

I've wrote some particle expressions that create random lightning streaks in my maya scene. My particles define the position and knots of my bolt and the expressions draw curves between the particles. The expressions also extrude nurbs tubes along these curve. These curves and nurbs tubes are constantly created or deleted when a new lightning streak spawns or dies. Thats why it's impossible to create geometry caches from these lightning streaks and so I have to rely on my expressions.
But the problem is that vray won't render these automatically created nurbs tubes during batch rendering. When I render single frames in Maya it works. The Maya Software Renderer is rendering my bolts even in batch mode that's why I thought it could be a problem with the renderer. Do you have any suggestions?

I'm using Maya 2013 and Vray 2.30.01.

[bigbossfr]

Hi,
Did you try a nightly build or stable build ?

[ojk]

It's a stable build.

[bigbossfr]

Expressions are complicated, it is better to send an example scene to the support to see what is wrong ^^.

[ivaylo.ivanov]

Yes, can you supply a scene? We had a similar problem with cached fluids. It turned out we must use a different fuction to change the time or Maya will skip some steps. You can test this with a nigtly build and a fake fluid container.

[ojk]

What different function do you mean to change time? A mel function?

Here's an example scene:

[tashko.zashev]

Hi,

Thank you for posting the scene file.
I managed to reproduce the same issue here and the scene is sent to our developers.
As soon as i have any update will get back to you.

[ojk]

Great, thank you!

[ivaylo.ivanov]

I don't think this setup will work. You are dynamically creating new geometry. VRay will not detect it. Probably will not work with maya software or mental ray either. You can try to create the nurbs and only show them when needed.

[ojk]

It works with Maya Software but not with Mental Ray. I also thought about hiding and unhiding existing geometry and that could be a solution in the end. But I'm asking myself why Maya Software is able to render it but Vray and Mental Ray not.