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Mental Ray Lighting info. - Getting maxwell quality

Posted: Thu Aug 03, 2006 7:02 pm
by JCAddy
Taken directly from Jeff Patton over at www.vizdepot.com

***EDIT*** the links came over weird, so here is the link to the original thread. Everything should work fine there.

http://www.vizdepot.com/forums/showthre ... #post33611



"Some users over at CGtalk have a really great thread on creating Vray & Maxwell "looking" renders with mental ray. The thread has grown to 96 pages and counting, but they have recently compiled it into two .pdf documents.

A LOT of the information is specific to Maya, but there are some parts specific to 3dsmax. Either way, the mental ray settings/concepts should be similar regardless of application.

CGtalk seems to be running a bit slow lately, so to save some headaches, here are direct links to the .pdf files:
M~R to mental ray: Getting the Maxwell look in mental ray
http://www.jozvex.com/CGTalk/Gettin..._Mental_Ray.pdf
http://www.absentdrone.com/CGTalk/G..._Mental_Ray.pdf
http://rapidshare.de/files/25808535...al_Ray.pdf.html

VRay-like interior renders with mental ray:
http://www.jozvex.com/CGTalk/Summar..._mental_ray.pdf
http://www.absentdrone.com/CGTalk/S..._mental_ray.pdf
http://rapidshare.de/files/26838812..._mental_ray.pdf

Original thread to the .pdf's:
http://forums.cgsociety.org/showthr...071#post3732071

Original discussion at CGtalk:
http://forums.cgsociety.org/showthread.php?t=190232 "

Posted: Thu Aug 03, 2006 7:06 pm
by misterasset
I think you did your links wrong. Could you please update them, I'd be very interested in reading this.

Posted: Thu Aug 03, 2006 7:08 pm
by Thomas An.
MentalRay is cool, but without reflective cautics ... it will be a stretch (or it will be restricted to materials that do not reflect light) in order to achieve realism.

I still like to see this scene done properly in Mental Ray
http://mywebpages.comcast.net/doehtal-r ... ntries.htm

Posted: Thu Aug 03, 2006 7:08 pm
by JCAddy
I just copied the original thread. Check the updated link at the top to ge tto the PDFs.

Posted: Thu Aug 03, 2006 7:08 pm
by DELETED
DELETED

Posted: Thu Aug 03, 2006 7:43 pm
by aitraaz
:shock: great stuff, cheers! :)

Posted: Thu Aug 03, 2006 7:50 pm
by andrebaros
That pretty much says it all. 96 pages, plus 3 PDF disertations to set things up in Mental Ray. When all you do in Maxwell is point and shoot. And the maxwell image will still look better. By the time I finish reading that "help" I can have several images rendering in Maxwell.

Posted: Thu Aug 03, 2006 7:59 pm
by jeffpatton
Thomas An. wrote:MentalRay is cool, but without reflective cautics ... it will be a stretch (or it will be restricted to materials that do not reflect light) in order to achieve realism.

I still like to see this scene done properly in Mental Ray
http://mywebpages.comcast.net/doehtal-r ... ntries.htm
Reflective & refractive caustics work just fine in mental ray. Certainly not as simple to setup as with Maxwell though:
Image

Jeff

Posted: Thu Aug 03, 2006 8:30 pm
by Thomas An.
Hi Jeff,

Thanks for this try. Yes there are caustics present in your image, but they are not correct.

Posted: Thu Aug 03, 2006 8:37 pm
by DELETED
DELETED

Posted: Thu Aug 03, 2006 8:38 pm
by jeffpatton
Well, I'm afraid this was just my own internal test so the light isn't setup as per those maxwell tests. But none the less, I'm curious, how are the caustics inaccurate? They "look" ok to my eyes (but I am getting old..lol) :lol:

If mental ray is indeed generating the wrong calculations then I can send those findings to the developers of mental ray.

I felt silly posting that here, but since I felt it was a decent example render of that scene with mental ray I posted it anyway. However, since this is the Maxwell forum please feel free to contact me via email instead of here with your findings on the erroneous caustics in mental ray. Jeff [at] jeffpatton.net

Cheers!

Posted: Thu Aug 03, 2006 8:44 pm
by wiz
Looks good to me. By the way, what was the render time on that?

Posted: Thu Aug 03, 2006 8:52 pm
by DELETED
DELETED

Posted: Thu Aug 03, 2006 8:58 pm
by aitraaz
lol...well jeff, I don't know if the caustics are correct or not (not an expert), but certainly a great image. Nice work on that :)

Posted: Thu Aug 03, 2006 9:01 pm
by Thomas An.
Jeff,

As a start. The inner ring caustic is incorrect. The shape is off and there is no secondary caustic. (ref: http://mywebpages.comcast.net/doehtal-r ... Images.htm)

The outer ring caustic is too narrow.

The coin caustics are not well defined.

(It seems MRay is using only a point light; which contributes to the problems)