Disappearing objects at 3rd frame of every render

[pizzaia]

Hi,

I'm trying to render a scene, all my objects are particles with an instancer connected to my source objects.

In the pre render scripts I changed the time slider to go to frame 1 before going back to the first frame of the render, to refresh the maya particles.

The problem is that on every render I have one or more pareticles that disappear, normally at the 3rd frame of the sequence. This always happens, but is not linked to a particular particle system. Sometimes, when I rebuild the scene, some other particle system gets this problem. (all particles have max count -1 and start frame at frame 1)
I don't want to convert the particles back to istances, due to some attributes that the particles are getting right now.

I'm using the last build of vray. and maya 2012, the latest build too.
Any idea why this is happening?

Thank you!

Gianluca

[vlado]

Can you post a scene here or send it to vraymaya@chaosgroup.com?

Best regards,
Vlado

[Julien BOLBACH]

Hi,

I'm working with Gianluca on this, let me me add few notes :
What we are doing is using particle systems and instancers to populate trees on a terrains. The trees are animated vrayMeshes.
The particle systems are just fed with positions/rotations/scales, and set to live forever, so they dont have any moving particles (in theory).
We have a lot of particle systems in our scene, and most of them are fine. But, some of them are disappearing after few frames (two frames in general), and popping in different places sometimes in few other places.
We've been investigating if it's a maya thing or a vray thing, but so far, not success. We tried to create for you a example of the scenes by stripping out most of our stuff, but the bug disappeared ... It is quite frustrating because each time we rebuild a new scene for the same thing, it doesn't work for other particle systems than the previous scene (even though they are the same).

Another thing I wanted to add, is that when we launch a render, we create a vrscene for the entire sequence, and the vrscene is refreshing the istancers for every frame, which we don't need for this particular setup. Because of this, our vrscenes are quite massive (few GB), when its shouldn't be needed. Would there be a way to add a vrayAttribute on the objects we dont want to update in the scene, so it would potentially solve our issue, and save us some disk space. The problem is, would it make our animated vrmeshes still animated ?

If we manage to replicate the bug in a scene we can send you, we will do it as soon as possible.

Thanks a lot,

Julien

[tashko.zashev]

Thank you Julien, we received the file and now doing some tests.
As soon as we have any information will get back to you.