Mental Ray Frequently Asked Questions

You're bound to come across problems while using the software. We've tried to document every possible problem users have encountered, and to list the solutions here.

For the most up-to-date version of the FAQ's, please refer to the Cinema Graphics website. Often we will update the website with common questions about a new release after it has gone out.

If your problem isn't in list below, contact us via email support@cinegrfx.com.


  • 1.0.0 - Rendering
  • 2.0.0 - Shaders
  • 3.0.0 - Trailer


    1.0.0 - Rendering
    UP DOWN
        Questions specific to rendering Mental Ray in ShadeTree.
    
    
    1.0.1 During rendering, I get the error 'CC: Command not found.'
    UP DOWN
        
        You need to have the C++ compiler installed. At your SGI's unix
        prompt, type:
    
    	[you@IRIS]: versions | grep -i c++.compiler
    	I  c++_dev.man.c++      12/06/95  C++ Compiler Man Pages
    	I  c++_dev.sw.c++       12/06/95  C++ Compiler
    
    
    
    
    1.0.2 During rendering, I get the error 'ray.irix5: Command not found.'
    UP DOWN
    
        Is ray.irix5 in your path? In your shell, type:
    
    	ray.irix5 -version
    
        This should advertise which version of Mental Ray you're running.
        If you get 'ray.irix5: Command not found', then consult your sysadmin
        to make sure your Softimage environment is properly setup, and that
        Softimage has the Mental Ray option installed.
    
    
    
    
    1.0.3 Why don't shadows work when rendering the ShadeTree object primitives?
    UP DOWN
    
        Bring up the Render Options Editor (Render -> Render Options), and make 
        sure:
    
    	> 'Trace' is on
    	> 'Shadows' is on
    	> 'Shadow Factor' is a value less than 1.0 (try 0.25)
    
    
    
    
    1.0.4 Why do my displacements look like they've been shrink wrapped?
    UP DOWN
    
        Make sure 'Para-Approx' in the Render Options Editor is set correctly.
        A value of 1.0 will give a shrink-wrap look for displacements. Crank this
        number up to slow your renders, but improve details in displacements.
    
    
    
    
    1.0.5 How do you use Softimage and ShadeTree together?
    UP DOWN
    
        An html tutorial is available on this subject. See the URL:
    
    	file:/usr/local/shadetree/mray/html/index.html
    
        ..and click on the tutorial that describes using ShadeTree and
        Softimage together.
    
    
    
    
    1.0.6 Displacement shaders don't look as nice on the patch object?
    UP DOWN
    
        Unfortunately, the 'patch' is made of 4 vertices, whereas the sphere
        has many vertices.
    
        This means you need to set your parametric approximation to a high number
        on patches (like 200), and adjust it down to a lower number on the sphere
        (like 10) to get similar results.
    
        If the ShadeTree patch had the same number of verts as the sphere, this
        wouldn't be necessary, but sometimes it's good to compare how a lores 
        object reacts to a shader. <I>Ok, it was a mistake, I admit it ;)</I>
    
    
    
    
    1.0.7 When I test 'patch' displacements on a 'sphere', my renders take forever!
    UP DOWN
    
        Same reason as above. 
        
        When rendering on the patch, set your parametric approximation to about 
        20x the value you use on spheres and cylinders.
    
    
    
    
    2.0.0 - Shaders
    UP DOWN
        Questions specific to writing shaders.
    
    
    3.0.0 - Trailer
    UP DOWN
    AUTHOR
        Greg Ercolano
        mailto:erco@cinegrfx.com
    
    COPYRIGHT
        (C) Copyright 1996 Cinema Graphics, Inc. All Rights Reserved.
    
    SUPPORT
        If you encounter errors in this document, email support@cinegrfx.com.
        Please supply the name of the file or manpage, enclose clippings of
        the erroneous text, and describe the error.