Problem rendering fluid effect with mental ray

[bravid2001]

Hello,
I am having a strange problem rendering fluid effects (steam/smoke). I have attached a jpg. I built it as a 3d container with emitter. It is taxing on my computer but I have been able to render this before. I have actually rendered the exact scene many months ago. It took some time but it finished. I am rendering with mental ray at production quality. The resolution of the container is 100, 100, 100. (I know thats high but I've done this before) I set my render settings and then go to batch render. I get the message "rendering with mental ray". It stays like this for hours. I have let it sit like this for up to 12 hours. If I hit cancel batch render, I get the message "sorry, previous batch render has not started". On 2 or 3 occasions, I have left the project to go into a different Maya project. When I try to render that one, I get "sorry, previous batch render has not started", which tells me that the previous render is still trying. I have also been able to start another batch render and the render that would not start previously kicks in and renders simultaneously.

I am onan Imac OS 10.7.5
4GB Memory
Maya 2008

[nico-sugleris]

Upload you scene and let me take a look

[nico-sugleris]

Well if at any point you'd like to have someone look at it, upload it and let me know 

[bravid2001]

Sorry I did not see your reply. 
https://dl.dropbox.com/u/15299215/WSramp26.ma

Above is a link to my dropbox where you can download the file. I am not sure how to upload the file via Creative Crash.

Thanks. 

[isysx]

I have had this problem before on a mac, but it was unrelated to the scene, sometimes the batch render  inside  maya breaks on a mac. I would highly recommend you do a render  through the mac osx terminal and see how it performs. If you set the verbosity mode to 5 it will give you  will see what is causing the render to bomb out if it does.

[bravid2001]

Hello isysx,
How would I do a render through the osx terminal? Also, I am not familiar with verbosity mode. Is that a setting in Maya?

Thanks.

[nico-sugleris]

starting with the basics

Have you fully cached the fluid before sending to render??

Also, you should seperate your fluid from everything and have a seperate scene with just the fluid and or any holdout objects.  No point in keeping all the particle / nparticle nodes if you just need a fluid render.  If maya has to load your scene and it ends up loading nparticle systems that may not be cached etc that can cause trouble.

It sounds to me like the fluid isn't cached, and or I was wondering why in the heck you are simulating with Hermite instead of linear?  

Hope the terminal command works for you, just be sure to run the Maya Terminal, and not just regular terminal (makes things alittle easier )  

[bravid2001]

Nico,
I tried to cache it out but it took a very long time and then it still wouldn't play.

So I should get rid of the particles. Should I get rid of any unncessary geometry too? Just leavingwhat the particles collide with? I used hermite because I watched a tutorial and it suggested hermite. Will that cause a problem? I will switch to linear.

I will do all this then try to cache again. Thank you!

Also, how do I run through Maya terminal?

[bravid2001]

 Changed hermite to linear. Deleted the particles. Also deleted any geometry that wasn't colliding with particles. Saved all this into a new project. Tried to cache but got "more than one item in scene is named fluidShape10" and " ^1s had no point to be cached". So I can't cache. BUT, batch render is working and it is rendering very fast. Ran some frames through fCheck and it looks good! So something in there worked! My guess is either changing the hermite or deleting the particles.

I'm not sure why it wouldn't cache though. And I'd like to know how to use the terminal.

Thanks for your help!!!! If you know anything about MayaLive, that's my next hang up.

[nico-sugleris]

No Problem, glad to see it worked.

I do A TON of production fluids and I think not once have I needed Hermite.   I'm sure someone out there will say I'm a fool, they sould refer to the actual fluids coding to see it will never catch up no matter what to Houdini  etc with a newer fluid solver.

Linear should work for almost all shots, also your fluid looks like it should have substeps at 2, and you never wanna work without caching.  That just leads to trouble on any network render solution.