Problem with maya fluids and vray physical camera?

[MartinB]

When we add the physical camera attributes to a scene with maya fluids in, on clicking render it starts a very long pre-render export process, stepping through every frame in the animation (over 500 frames)

Deleting the physical camera means that it starts rendering after it exports one frame (or 3 frames if motion blur is on)

We're locked to vray 2.00.04, so I can't test if its been fixed in later releases.

cheers

[bigbossfr]

When we add the physical camera attributes to a scene with maya fluids in, on clicking render it starts a very long pre-render export process, stepping through every frame in the animation (over 500 frames)

Deleting the physical camera means that it starts rendering after it exports one frame (or 3 frames if motion blur is on)

We're locked to vray 2.00.04, so I can't test if its been fixed in later releases.

cheers

But why are you locked to vray 2.00.04 (this version is old, more than 1 year) ?

[MartinB]

But why are you locked to vray 2.00.04 (this version is old, more than 1 year) ?

Trust me its not by my choice.

[bigbossfr]

Trust me its not by my choice.

Yes, but :
- if it is a bug, ChaosGroup will fix it, and you can not have the fix because you locked.
- if it is already fixed, you can not upgrade because you locked.

?

[MartinB]

Ok, I was asking for a clarification of if its a bug, if its already been fixed, or there's plans to fix it. This would add weight to my case to get a system in place for installing different versions/nightlies

[vlado]

I think that was a bug that we fixed in a later build, however the pre-export will still happen in certain situations where we need the entire camera path at the start of rendering. In any case, we also added an environment variable that allows to skip the pre-render export altogether.

This is still also somewhat of a Maya issue though; it updates the dynamics simulations even though we don't need any data from them during the pre-export.

Best regards,
Vldao

[Morbid Angel]

MartinB, you can clip the time range inside maya UI, to start at whatever frame you want to render and this will avoid the runup. Its not ideal but it may be helpful in your case.

[vlado]

For batch rendering, you can also use a pre-render MEL to do that using the "playbackOptions" command.

Best regards,
Vlado

[MartinB]

Thanks guys!

Also any news on when 2.3 official will be out? I'm pushing to upgrade to 2.2 at the moment, but if 2.3 is just round the corner we might hold off for that.

[bigbossfr]

Hi,
I have the same problem with a hair cache (a sequence).
Vray take 4h (of Pre-render export) to start the render at the frame 60 for example.
The problem in preRender mel is : how can i get the "render frame time" ?

Looks like "currentTime -query" doesn't work.

And preFrame run after the Pre-render export.

Thanks.

[vlado]

In recent nightly builds, you can set the MAYA_DISABLE_BATCH_RUNUP environment variable to "1" (without the quotes) to make V-Ray skip the pre-render phase, if this is where the slowdown occurs. Also, make sure your fluids are cached.

Best regards,
Vlado

[bigbossfr]

In recent nightly builds, you can set the MAYA_DISABLE_BATCH_RUNUP environment variable to "1" (without the quotes) to make V-Ray skip the pre-render phase, if this is where the slowdown occurs. Also, make sure your fluids are cached.

Best regards,
Vlado

Can i set the env in preRender mel like : -preRender "putenv "MAYA_DISABLE_BATCH_RUNUP" 1;", or i must to set the env before the batch ?

Thanks.

Edit : ok, it works with preRender.
Question : "certain situations where we need the entire camera path at the start of rendering", when can i disable the pre-export ? I have physical cam, my physical cam will work ?

[vlado]

I have physical cam, my physical cam will work ?

Yes, it will work. Situations where V-Ray needs the camera path at the start of the rendering are when you calculate the light cache in "fly-through" mode, or when you use the "Use camera path" option for either the light cache or the irradiance map. We also use the pre-render phase to detect any animated objects that we might miss otherwise.

Best regards,
Vlado

[bigbossfr]

Ok, thank you Vlado.