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View Full Version : Rendering Issue with maya 2011 and mental ray


JohnPetrucci
01-20-2011, 01:52 PM
Hey guys, I'm trying to render a scene with maya 2011 and mental ray using final father; I have a vehicle with different kinds of reflective shaders. When I have the camera close to the object, it renders as I have expected, but when I have the object very far away, it takes a LONG time to render, it's insane..
Is this a bug from maya 2011 or I have my settings messed up???
Help!!

I'd have loved to be able to upload the scene file for any of you to test it, but it's work related.

thanks in advance!

AutodeskLab
01-20-2011, 05:17 PM
i would try to figure out how environment is...
final gathering is not a good idea for quick rendering.

InfernalDarkness
01-21-2011, 12:28 AM
What's happening is simply that the FG rays are taking longer to converge on their solution (read: work through their math) when the camera's further away. So while the FG "rays" are working very well up close, from a distance they're not "hitting" as much geometry as quickly (to coincide with your render resolution), and thus taking much longer to calculate. This same problem arises when you make a raw interior scene (for example) without the sun/sky, and all of a sudden FG is trying to bounce out of the scene off to infinity forever and taking forever, while the interior of your scene is all splotchy and ugly. The solution for interiors is portal lights - they tell the scene to converge all your FG data INSIDE the scene instead of sending it past the portal light's shape. More info on this in the Maya help.

So is your car scene inside a building or warehouse, or "outside"? Can you replicate the scene without the car, using say a sphere or something and test my theory that way? And if so, perhaps try using portal lights instead to concentrate the FG?

Just some ideas. If you get some time, try a simpler test-scene that you can share with us and perhaps we can help better.

final gathering is not a good idea for quick rendering.

Very helpful AD employees of course. Too bad your information is ten years old, my friend. FG renders blazing fast for me - I learned how to tune it so that it will do so, no thanks to your implementation of mental ray inside Maya though, by the way.

JohnPetrucci
01-24-2011, 05:01 AM
thanks for your reply InfernalDarkness, I found the solution to my problem: IBL
For some reason in maya 2011, if I create the IBL, it would take longer times to render, so I deleted it to see if it would affect the speed and my render times went from 5 mins-10 mins to 1-2 mins.

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