View Full Version : MentalRay renderer problem in animation.

07 July 2002, 07:54 PM
I currently use MentalRay2 for my rendering.
Not a very long time ago I used it for the first time(5 weeks ago or less)
I use 3dmax4.26
Here are my questions:
1-When I render detailed scenes from a distance it becomses
something like jpg pictures with high compression.
This makes bad sense specially in animation,because other
objects are in good quality and that special part is noisy.
I have changed sampling rates and checked jitter option too but
still it's noisy and needs much more time to be rendered.
no considerable improvment in quality in animation (not still images alone)

Is there any other way to reduce this things in other softwares
like AfterEffects?
I imported the animation in AE5.5 and used motion blur and
frame blending,but still that part is noisy(like I'm watching it through a noisy glass)

Perhaps I must change the filter in MentalRay?
I always use Box filter,(Is Mitchell better for this problem?)
What's your idea?

2-Is it possible to render scenes in 3dmax into .mi files and then
render it in MentalRay2?
Cuz once I tried to do this and nothing happened using this command:
D:\Mental Ray\Ray.exe D:\folder\test.mi

If it is possible Sb here has MentalRay3 for Maya.
Can it render .mi files written by 3Dmax to MentalRay connection?
I know it's faster than MentalRay2.

Thanks in advance.
Sepehr :hmm:

08 August 2002, 08:54 AM
Hey guys.
Nobody has replyed to me.
Maybe because of the long text.
So I make it shorter and please reply to it if you're interested.

What's the command in MentalRay to render a .mi file?
How may I reduce noise in AfterEffect?(I don't wanna blur all
the picture just that noisy part because of renderer low sampling rate?)
Thanks in advance

08 August 2002, 09:37 PM
I dont use Mental Ray personally, have you tried typing

D:\Mental Ray\Ray.exe /?

to see if it gives you a list of command line switches? Have a look in the manuals as well, there is probably something you need to specify, like whether id renders to a Frame buffer, or an output path & filename.

You may just have to play with some dust & scratches filters in your comping program if you dont want to render again. No magic cure to rid noise without loosing detail unfortunately, have you got some kind of grain removal tools in AFX?

08 August 2002, 10:47 PM
The mi files output by max don't include the output file specification (even if you had Max rendering to a file)

Try something like:
ray -file_name test.tga -file_type tga test.mi

The test.mi file was output by Max. I was in the directory when I issued the command, and it created test.tga in the same directory.

It's useful to add your mentalray bin directory to your path if you want to do this often (so you don't have to type the whole path to Ray.exe each time).

As to the noise in the distance, what file type are you rendering to? If it's compression noise, you could render to sequential targa or tiff files (they're lossless, so no copression noise), and build your animation in After Effects. It could also be texture parallax. Can you post an image demonstrating the problem?

08 August 2002, 05:50 PM
Thanks for replying to me.

Das,that command worked ,thanks ,but it doesn't render animation.
It only renders the first frame of the animation.
Does 3dmax convert each frame of scene into indivisual mi file?

About the manuals:
The manuals that I have only cover the structure of MentalRay
not it commands.
Maybe some can be found some at mentalray website.
I'll check that again.
But in my last search I couldn't find any.

About noise in animtion:
I've attached an image.
Somebody told me to use "Reduce interlace filcker" effect in
AfterEffects but I didn't like that,because although it was
blured,the noisy parts where seen.
Some thing like how we see stars from the earth.
(they change their brightness eachframe).

01 January 2005, 02:16 PM

I have come across similar problems before. Open up your render click on renderer tab. Go to Sampling Quality and turn off 'lock samples' and turn on 'jitter' ... this can help reduce these problems. You could also try increasing the samples per pixel to min :1 and max : 16.

Don't know if this is of any help, but worth a try.

01 January 2005, 01:36 PM
ok here we go:
First :


1 = do you use some GI? FG?
2 = do you use some render effect like intensity cliping? Dithering?
3 = you use box 1,1?

if 1 = yes goto 10
if 2 = yes goto 20
if 3 = yes goto 30

10 if so, it may have something to do with the "compresion" effect. simply reduce the radius in the gi/fg seting to 0,1 ; 0,1

goto end

20 if no turn them on. also turn on jitter.

goto end

30 if so, pick mitchel, its better and does not blur the pic too much

goot Luck! Mr 2 is slow, and does not produce the best fg/gi, but it is a good base to render pics..

01 January 2005, 04:37 PM
whats your min max samples set to?
what image format are you rendering to?

for final renders I usually find that samples needs to be min 0 max 2 (1-16 samples per pixel) or sometimes min 1 max 3 (4-64 samples per pixel). Never use the box filter, mitchell is much better. And of course make sure you're not rendering to a lossy image format (such as jpeg)

01 January 2005, 09:07 PM
This thread was started in 2002!
Thats funny...
During these years I've ported from Max to Maya and now am using PRman for rendering and
not MentalRay any more...

01 January 2005, 12:29 PM
That is funny - I never check the original date, only the last post. will have to starting reading the dates more carefully....


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