driving me mental ray

# 1 30-11-2007 , 01:34 AM

Registered User
Join Date: Nov 2007

Posts: 75

Hi, everyone. Cool site. Haven't had a proper look around, but will soon.
I recently finished modelling a fairly large scene and rendered it. Fine. No problems. Turned out exactly as expected. Then I thought I'd re-render it using Mental Ray with raytracing and global illumination and all that. A few shaders needed to be altered to get a good look as I expected, and my ocean looks awesome. But a few things struck me as odd:
Firstly: No paint effects; just dissapeared. (in render only) Does Mental Ray not render paint effects?
Secondly: The original had a narrow depth-of-field with a keyframed focus-distance, but when I render a frame in Mental-Ray it appears to have infinite depth-of-field.
And finally: Where has the fog gone from my spotlights? It's not a huge problem 'cause I can always knock out another pass using Maya software and just render the fog (can't I?), but does seem a bit weird.
Any help will be much appreciated. I've gotta go before anyone I know sees me in a library.

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# 2 30-11-2007 , 01:46 AM

Registered User
Join Date: Jan 2005

Location: vienna

Posts: 1,095

I think mr doesnt render paint effects - but that isn´t proofed user added image

mr also does not render your spotlights light fog - this is proofed user added image

you´ll have to add something like a partiVolume - do y google search for that. there is some good tutorial out there. i think this was it

https://www.jhavna.net/main.php?page=scatter

about the dof, maybe you have to ad a lense shader for mr to do that.

I´d try to testify but maya is baking maps right now..

everything starts and ends in the right place at the right time.

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# 3 30-11-2007 , 09:29 PM

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Join Date: Jul 2006

Location: London

Posts: 567

As far as I know Paint Effects do not render in MR, you could either render a software pass for the PE and comp on afterwards, or alternatively convert your PE to geometry.

I guess the good thing with rendering the software pass is that you could render out the PE and the fog in the same pass to save a little time.

Personally I wouldn't render them together but I guess it depends on how long stuff is taking to render out etc.

Chris

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