Hi there deviantdreamworks,

Nice pic, just wondered how long was the render time and on what speed machine?

I also have been playing around lately with mental ray. This image rendered on my p3 450 in about 8 minutes using a mix of GI and final gathering.

re jim

about 3 mins on a Xp 2100+ 1.8 Ghz wit 642 Mb pc-2100 (somewhere around there just above 512 :D)

Hi there Deviant Dreamworks,

The 3 minute render, was that at the size that you posted?

If so, did you only use final gathering, or did you use a mix of GI and final gathering. A mix of GI and FG gives a much greater approximation of bounce light/colour bleeding than just final gathering or GI by itself. Also, just as importantly you can get much quicker render times using the mix as the final gathering is used primarily to 'smooth' out the rough but quick GI solution.

Here is some images that I rendered with mental ray tonight.
My machine is a P3 450, not the sort of machine that you would hope to batch render GI stuff in.

The first two are using just a single spot light.

Time to render 1 minute

Spots are good for Photon use because unlike point lights that throw light and photons in all direction spot lights concentrate the light and photons in a single direction which means faster renders.

the middle image (same as top left) but with GI turned on.

Time to render 3 minutes
Settings are:

Spotlight:
Energy 180,000 (all channels)
Exponent 2
Physical Yes

Area lights turn "Off" (Unless you want excessive render times).

Mental Ray render globals:

Global Illumination tab:
GI accuracy 800
Gl radius 1.35

photon volume accuracy 35
photon volume radius 1.0

Max reflection photons 20, 20, 40


The lower images are the same but with 'final gathering' turned on to "smooth" the rough global illumination.

Time to render 4 minutes

final Gathering tab:

final gather rays 100
Min radius 800
Max radius 1600

Sampling tab:
Min 0
Max 2

Jitter Yes
Gauss filter

Hope this is helpful to someone. With renders this quick one could easily render animations not just pretty single images.


Jim has attached this image:


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http://www.xsibase.com/cgi-bin/yabb...;num=1039191370

One is from xsi base but the principles apply to Maya to mental ray as xsi uses mental ray as it's base renderer. As far as speed goes I have rendered the same scene in both maya and xsi.

Maya gave quicker and better results!!!!!

re Jim

nice results
 

This is some awesome information gathering for mental ray. I thought I'd add a link that helped me with some of my settings. I'm getting some very nice renders with the settings suggested here (fast renders too)
http://www.steven-tubbrit.pwp.blueyo...utorial_02.htm

No light inside sphere
 

Did you have "Use shadow maps" turn on on your dir light?
I think this is why no light was lighting the scene when inside a sphere.

wow, i ahve mental ray and i was thinking that what the heck was it useful for

I LOVE Mental Ray, ever since it came out I don't think I've used Maya's renderer once!

I'm making a hotel hallway at the moment (just for fun), it's still in the very early stages but there's a render attached.

It's totally lit by the rectangle lights (they're just planes) using FG and GI, there's depth of field too just for fun.

It got a bit artifacty from the jpeg compression, but nevermind.

How long did that take to render?

Gulp, 2 hours!

I may have gone a bit overboard on the FG settings though. It was rendered on my Athlon XP 1800+ with 768meg of DDR ram.