trouble rendering maya fluid effects

[foureyes]

We sent a Maya fluid render job to the render farm. The first few frames are ok, took less than 1 min. to render. However, the later frames gradually take more and more time to render, such as up to a few hours. And then finally failed. However, if I split to job to 1-100 frames, 101-200 frames, etc., it seems fine. It seems maya rendering need preprocessing for each job. The more the no. of frames, the more time it need to preprocess. Is there any way in qube that can tackle this problem, rather than having to set different jobs manually?

Thanks.

 

[eric]

You are probably experiencing the effect of "runup." Since fluid modeling is a simulation, it relies on previous frame information in order generate the state of the current frame. Unless your simulation data is properly cached, rendering a given frame would require the simulation of the previous frame, which would also require the simulation of the previous frame to that, and so on.

The net effect, since each subjob renders 1 or more frames based upon what they get from the Supervisor, is a full "runup" for each frame. As you progress through the set of frames, the runup gets longer, and consequently so do your renders.

You'll want to investigate "baking" or otherwise pre-generating and caching fluid simulation data so that any frame can access the cache for its simulation data. Make sure the simulation is set in the scene to use the cache.

If this is not possible, it may ultimately be more efficient to run all the frames on a single host.

[jbrandibas]

You definately have to cache your fluids before submitting.  This would go for any simulation whether it be fluids, particles, cloth, etc...

In Maya, if you have never cached fluids before, you can cache them via the Fluids menu in Dynamics, but the thing you have to remember is the cache is not written fully to disk until you save your scene. So if you are generating the cache then immediately submitting to qube, you will have the same problem.  So, cache the fluids, save the scene, then submit and you should be good to go.