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
3.0.0 - Trailer
Questions specific to rendering Mental Ray in ShadeTree.
You need to have the C++ compiler installed. At your SGI's unix
[[email protected]]: 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
Is ray.irix5 in your path? In your shell, type:
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.
Bring up the Render Options Editor (Render -> Render Options), and make
> 'Trace' is on
> 'Shadows' is on
> 'Shadow Factor' is a value less than 1.0 (try 0.25)
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.
An html tutorial is available on this subject. See the URL:
..and click on the tutorial that describes using ShadeTree and
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>
Same reason as above.
When rendering on the patch, set your parametric approximation to about
20x the value you use on spheres and cylinders.
Questions specific to writing shaders.
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Please supply the name of the file or manpage, enclose clippings of
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