View Full Version : Which Maya utility nodes are supported by Mental Ray?

04 April 2006, 11:46 PM

Does anyone know which maya utility nodes are supported by Mental Ray? Or the ones that are not?

I followed a tutorial called "Discrete Tiled 2D Noise" from Digital Artform. There's a shading network to build in there that uses an expression. It works ok with Maya Software renderer, but not with Mental Ray. I was wondering if the problem is because of any utility node used there or because of the expression...

Until I made this tutorial I thought that everything that could be rendered with Maya Software could also be renderer with MR. It looks like it's not like that. Or was the problem only in that case?

So the main question is: what should I avoid using in a shading network if I'm going to render with MR?

Woops... Forgot to post the URL to the tutorial...


04 April 2006, 08:52 AM
The thing that is not supported in your case is expressions. The utility nodes all work with mental ray.
You cannot use an expression to drive e.g. the UV placement like in the tutorial, instead the current plug value of that attribute, calculated at the start of the frame will be used - you either need to find a way doing it with shading nodes, or write your own mental ray shader. Pixero wrote a mosaic shader for that purpose:

04 April 2006, 04:11 PM
Hi Floze!

Thanks a lot for your help. I'll check pixero's page for that shader.
It's a relief that I can use any maya utility nodes with MR. I was really worried about that. I thought there could be some of them that weren't supported because of an info I read in the help in the "What's New in Maya (7.0)" section:

mental ray for maya now supports the following utility nodes:

- Distance Between
- Remap Color
- Remap Value
- Remap Hsv.


04 April 2006, 12:42 PM
I wonder if we ever will see expressions driving render-nodes working in mentalRay in the future... I surely hope so.

04 April 2006, 12:10 AM
It would be great, wouldn't it Tobbe?

I also wish MR shader networks get as easy to setup as Maya 's. I mean, it isn't as intuitive... At least for me. I'm having a hard time learning it. Everytime I have a doubt I spend half a day looking for the answers. And some of them remain hidden. Even things that should be very simple. But I'll get there...


05 May 2006, 09:52 PM
I wonder if we ever will see expressions driving render-nodes working in mentalRay in the future... I surely hope so.

See this post:

05 May 2006, 07:08 AM
Nice! I'll see what I can do with that shader...

08 August 2006, 06:54 PM
this is crazy... i have an expression connected to a few objects visibility. the expression turns the objects on and off depending on an attributes value that is connected to a locator.

to put it simply i tried to create a master switch to control many objects visibility at one time.

rendering with software render works ok.. but now im comming across crazy errors with mental ray.

is there a way to solve this problem ? or do i have to animate each objects visibility separately because mr cant understand my expression ?

08 August 2006, 08:40 PM
Have you tried my JS_Expression MR shader in the link above?
It doesnt do MEL, but math expressions works.

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08 August 2006, 08:40 PM
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