Maya Batch Render Problem

[dougie0047]

Hello,

I've got a problem with the batch rendering I of animation I've done. Basically it freezes after roughly 10 frames, everytime. This is of course annoying when the total animation is 1270 frames long.

The scene is quite heavy with dynamics that were cashed and thus turned into keyframes, and I also have cashed particles (all particles are sofware rendered), so I don't expect the rendering to super fast, but the freezing strikes me as puzzling at best.

So, what I've discovered is that with every new rendered frame the used system memory increases a little bit, and when the batch renderer get's to eat up around 1.3 GB of memory it just stops. It keeps standing on 1.3 GB RAM, and the CPU falls down towards 0 %. The increase in memory usage progressively increases also when the scene gets lighter (when particles start dying), and when I start up again from the frame that failed to render the scenario repeats itself, with mem usage going from low to high.

Firstly is this really normal? And if not, what can I do to fix the problem?

I have tried to read up a bit on scanline rendering, but I'm a total noob with that and don't even know where one is supposed do this scanline rendering from, so that was a failure.

Any ideas guys?

Thanks

Dougie

[gmask]

It's a memory leak

basically to work aroudn this you need to render in small packets ..

there are a number of free batch render managing softwares listed in the software section on this site.

Using one of these programs it will automatically issue renders in small "packets' of frames

Another way you could go since you are using the standard renderer is to add the -rep 1 flag to your render command and repeat the render command many times.

The rep flag tells the standard renderer to not write over existing frames. So if you have the same render command listed over and over then it will skip any frames render when it crashes.

So you batch file would look like this..

render.exe -r sw -rep 1 myscenefile.mb
render.exe -r sw -rep 1 myscenefile.mb
render.exe -r sw -rep 1 myscenefile.mb
render.exe -r sw -rep 1 myscenefile.mb
render.exe -r sw -rep 1 myscenefile.mb
render.exe -r sw -rep 1 myscenefile.mb
render.exe -r sw -rep 1 myscenefile.mb
render.exe -r sw -rep 1 myscenefile.mb

and so and so on

[dougie0047]

Thanks for your reply gmask!

Good to hear that someone can puts words on my problem. But, what exactly does a "memory leak" mean? Just curious.

I will look for one of the programs you referred to.

Also, were exactly would I type in this - rep 1 flag that you talked about?

Thanks again

Dougie

[gmask]

Memory leak is an issue where a function in a program does not properly flush memory it is done using so it will continue to use more and more memory.

In order to take advantage of the strategy I outlined above to deal with this you would need to make a btach file.

On windows a batch file is simply a text file that ends with .bat inside the file are lines of commands such as..

"C:\Program Files\Alias\Maya8.0\bin\render.exe" -rep 1 myscenefile.mb

Any file path that has blanks spaces in the name will need to be put in quotations. As long as the batch file is int he same directory as your scene file you will not need to give the full path to the scene file.

[joojaa]

Or you can loop trough the sequence instead by forced breaks, this way theres less chance of something catastrophic happening (and it works for stuff that dont have -rep. Although theres only slim chances of catastrophes happening, but more then that you'd be less likely to have many empty frames).

basic idea is

FOR /L %i IN (1,10,1270) DO FOR /F %j IN ('set /a %i+9') do render -s %i -e % file.mb

if you put this in a batch file instead of commandline (where is tested this) use %% instead of %

After this line do a few lines like gmask suggested.

Anyway theres no way to avoid completely memory leak as a 3d authoring application is ultimately a visual programming language so the users actions matter.

for a better idea of what you can do heres a batch example that is a bit old (i never used it beyond one project since i wrote one in python that works a s a daemon/service, but thispone works works), serves as a example to teach you what you can do. It renders animation sequences as tiles to be stitched later.

http://users.tkk.fi/~joojala2/highend/renderTiles.bat

anyway theese things really make for quick and dirty solutions for a number of things

[dougie0047]

Once again, thanks guys, for your replies!

Cheers for letting me know what a memory leak is, and I'll look into your suggestions and see if I can make things work on my own.

Thanks

Dougie