mental ray question

# 1 25-05-2007 , 01:13 PM

Subscriber
Join Date: Dec 2006

Location: Plattsburgh New York

Posts: 1,222

Why does it render with these round specs of light on the front like this?

user added image

I'm don't know much about mental ray so I'm including everything I have changed or may have changed. Hopefully this is helpful for you to help me out.

Render Global Settings

Ray Tracing: On
Reflections: 2
Refractions: 2
Max Trace Depth: 4
Shadow Trace Depth: 2
Scanline: On
Faces: Both

Global Illumination: On
Global Illum Accuracy: 200
Global Illum Radius: 2.00
Global Illum Scale: White
Photon Volume Accuracy: 64
Photon Volume Radius: 0
Max Photon Depth: 5
Rebuild Photon Map: Check
Max Reflection Photons: 5
Max Refraction Photons: 5

Two Spotlights, no decay
Main Spotlight
Emit Photons: Check
Photon Intensity: 24000
Exponent: 1
Global Illum Photons: 1000

Second Spotlight
Emit Photons: Check
Photon Intensity: 16000
Exponent: 1
Global Illum Photons: 1000

- Mike

https://rhetoriccamel.blogspot.com

Quote

# 2 25-05-2007 , 01:31 PM

Subscriber
Join Date: Jun 2003

Location: stuck in the 90's boston, USA

Posts: 1,871

Global Illum Photons: 1000

i would increase to like a million

Quote

# 3 25-05-2007 , 02:46 PM

Subscriber
Join Date: Dec 2006

Location: Plattsburgh New York

Posts: 1,222

I turned it up to 1000000 and it got rid of the problem, but other than that I don't see much of a difference and it turned my 40 second render time into a 45 minute render time. Is there really a need for it to be up that high on both lights?

user added image

I even forgot to do a poly smooth on it before the render. Thats alright I'm lacking in colors for the lights, interior, and tires

thanks for the help vlad... any other tips to make this car render look better I'm all ears.

- Mike

https://rhetoriccamel.blogspot.com

Quote

# 4 25-05-2007 , 11:19 PM

Senior Software Developer
Join Date: Jan 2005

Location: Livingston, Scotland

Posts: 1,701

Turn off Caustics, and just leave GI in place.

Chris (formerly R@nSiD)
Twitter
When the power of love overcomes the love of power the world will truely know peace - Jimmy Hendrix

Winner SM VFX Challenge 1

3rd Place SM SteamPunk Challenge (May 2007)

Quote

# 5 29-05-2007 , 08:15 PM

Subscriber
Join Date: Dec 2006

Location: Plattsburgh New York

Posts: 1,222

I never turned caustics on, thanks though.

- Mike

https://rhetoriccamel.blogspot.com

Quote

# 6 30-05-2007 , 03:04 AM

Moderator
Join Date: Jan 2004

Location: Michigan, USA

Posts: 2,998

You could try final render stage-2.

Or you could try to actually figure out how to set the 8 bazillion properties of mental ray. I would recommend first getting a 15 year phd in pan-hyper-dimensional-quantum-photonic-light-physics that could help to understand the settings (a little). lol

Sorry to be making jokes but I have recently been struggling with mental ray and man that package really drives me insane. There are no useful guides to workflow and help files in maya are useless. They read like a poorly translated japanese to english stereo manual.

I have paid for a couple of tutorials and they were not much help. The instructor seems to randomly pull values out of his butt and does nothing to explain what they do and why. As an example at one of my favorite lessons he says and I quote ...to use this option you will have to make quite large changes in the antialieas settings... and then he proceeds to change the value from 0 to 1. Hmmm his definition of "very large" and mine are quite different. It would seem to me that moving from 0 to 1 is the smallest possible unit of change you can make! To make things worse the change made the render go from 7 seconds to 45 seconds.

To me mental ray is too complicated and with no users guide that explains workflow it's almost mystical as to how it works. I have seen stuff done in vray and have fiddled with a trial version of final render and they both seem more intuitive to use.

Last edited by ctbram; 30-05-2007 at 03:07 AM.

Quote

# 7 30-05-2007 , 07:53 PM

Subscriber
Join Date: Dec 2006

Location: Plattsburgh New York

Posts: 1,222

yeah mental ray is a pain right in the ass. I've been using maxwell 1.1 and it seems pretty good, I just hate the render times, but then again mr wasn't rendering any faster when I boosted up the photons.

- Mike

https://rhetoriccamel.blogspot.com

Quote

# 8 31-05-2007 , 02:21 AM

Subscriber
Join Date: Mar 2005

Location: Illinois, USA

Posts: 250

MR's many settings can be nice actually. You can increase the photon size and then the filter so that the samples are blurred together. Really it's all about the tweaking.

www.funkybunnies3d.com

Quote

# 9 31-05-2007 , 03:31 AM

Senior Software Developer
Join Date: Jan 2005

Location: Livingston, Scotland

Posts: 1,701

Mental Ray is fantastic, its just very dificult to set up and use. It just takes time and practice. I refuse to use Maxwell due to a couple of things.

Does not work directly in Maya (MR does)
The render times are rediculus

Try Renderman better renders and 1000x faster.

Chris (formerly R@nSiD)
Twitter
When the power of love overcomes the love of power the world will truely know peace - Jimmy Hendrix

Winner SM VFX Challenge 1

3rd Place SM SteamPunk Challenge (May 2007)

Last edited by R@nSiD; 31-05-2007 at 03:34 AM.

Quote

# 10 31-05-2007 , 04:32 AM

Moderator
Join Date: May 2005

Location: Manchester Uk

Posts: 6,300

If you spend a little time with MR you can get some great results with it for quite a small render time, for example the guitar that I did was rendering a frame in 20 mins, Once you get the hang of what the settings do you can get going pretty fast.

The more photons that you add to the scene the longer the render time, I doubt that it would get to the render times of Maxwell though.

End of the day it does take a bit of fiddeling to get the render looking nice, but its worth it.

"No pressure, no diamonds" Thomas Carlyle

Quote

# 11 01-06-2007 , 10:08 AM

Subscriber
Join Date: Dec 2006

Location: Plattsburgh New York

Posts: 1,222

alright thanks for all the help, I'll be giving mental ray more of a chance. I have some tutorials that I'll be checking out to kind of get the feel of it and from there just tweek. I feel like I'm always tweeking things, if it's not geometry, it's rendering, and if it's not either one of those then I'm tweeking colors in photoshop. Thanks again for all the help!

- Mike

https://rhetoriccamel.blogspot.com

Quote

mental ray question

Posting Rules Forum Rules

Similar Threads

Topics

Free Courses

Full Courses

VFX News