Can't get ram usage under control

[jonavark]

I am having a very strange problem trying to render something. Even a small patch is using all available ram. Can I get you guys to take a peek at my file and tell me what I am doing wrong? If I email you a link to my ftp site, rather than post it..?

One of the MR errors I am getting is "Attempt to access null DB tag" This is new.

thanks!

[iToo]

Sure. Please, send us the ftp link. We will take a look to it.

The "null db tag" is a typical mental ray exception. It may happen by multiple causes.

[jonavark]

OK.. I sent you the file link

I had been working along, everything was fine. I had set the density I liked and then, after setting up my render it started to fail. With the Null DB tag error. I have isolated the error down to a forest object. Which I have replaced a few times. It's a rather involved project so it takes some time to do.

I have been trying to rebuild my scene but not having much luck. Using the same sizes I was using before yields smaller plants for some reason. And I can no longer set the density to where I need it to be. But for the past couple of days it was all working well.

This time I rendered, then set THRESHOLD down from 50 to 20 and the null tag error started showing up. Consequently, raising the density X value and setting threshold to 50 again didn't resolve it. It fails every time now. But I don't get a warning about exceeding the number if objects.

 What is threshold actually doing ? The manual only has one line of text for it.

I am using xrefs, importing from the library.

[iToo]

Definitively there is something wrong in this scene, but i cannot find what is exactly.

I tried to merge all the objects in a new scene; it renders fine, stable and using not more than 2 Gb.RAM. Even i can render much more items without problems.

Please, try that: create a new scene and import the objects from this. If it is stable, try modifying the render settings and effects progressively.

[jonavark]

At a certain point it becomes a very lengthy process to rebuild scenes. I wish Mental Ray error messages were a little more clear! I can't tell if it is a FP thing or not .. I have only had 3.81 installed for a week or so.

This might be a hint... When applying new forest items to the ground plane often they will show up completely flattened out and I won't be able to get them to any height at all. I hadn't seen that in older versions..

I have to thank you for taking the time to look at that scene.

I guess I will revert to an older file and try to catch up.

Thank you very much for your time. Really appreciate it.

[iToo]

This might be a hint... When applying new forest items to the ground plane often they will show up completely flattened out and I won't be able to get them to any height at all. I hadn't seen that in older versions..

This seems a different issue, we will check it. Anyway, it should have not effect on render.

I'm testing a bit more the scene, with the same result: Mental Ray takes all the memory available and crashes. Instead, importing all the objects in a new scene solves the problem. I think it's a MR issue, because Forest should have not different behaviours if the object doesn't change. In any case, it is a strange problem.

[jonavark]

Thanks

I will be working it today. If I find anything that may be relevant I will post it here, just in case there is something related..