Microsoft KB Archive/149723

= Microsoft Knowledge Base =

BUG: 3D Has Problems Rendering Instances In Mental Ray
Last reviewed: April 19, 1996

Article ID: Q149723

The information in this article applies to:


 * Softimage 3D for IRIX, version 3.0

SYMPTOMS
Softimage 3D has problems rendering instances in mental ray. When rendering a scene with a simple sphere and a few duplicates of it, mental ray renders as it should and the memory used is what is to be expected.

However, when rendering a scene with the same simple sphere and the same number of duplicates created as instances, mental ray cannot render a sequence. In this case, one of the following occurs:


 * mental ray writes out a core file.
 * mental ray displays a segmentation fault.
 * mental ray displays a bus error.
 * mental ray displays a system MEMALLOC error.

Also, the memory used rendering in mental ray appears to be six times larger when instances are created than when mental ray is used with geometry duplicates.

Also, mental ray rendering results in an mi file size that's about 25 times larger when instances are created as compared to the file created when mental ray is used with geometry duplicates.

RESOLUTION
To work around this bug:

 Expand instances before rendering in mental ray. -or- Do not put the instances in a hierarchy when rendering in mental ray. -or- To keep the instances in a hierarchy when you are rendering in mental ray, place each instance under its own null parent. Then use a global parent for the instance/null hierarchies.

STATUS
Softimage has confirmed this to be a bug in the Softimage product listed at the beginning of this article. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

NOTE: Softimage Inc. is a wholly owned subsidiary of Microsoft Corporation.