Speed, Speed, Speed! The goal of version 2.1 was to increase rendering frame rates. Though the results vary from application to application, we've seen increases in the 20% to 400% range. On occasion, an application achieves a 1000% increase (10x).

If you look under the hood of the Open Inventor 2.1 toolkit, you would find improved algorithms as well as brute-force code optimizations. For example:

• The scene graph traversal has been re-implemented,
• The mechanism for keeping track of current material properties during traversal has been redesigned,
• The shape rendering loops have been re-implemented,
• The view culling algorithm is new,
• The mechanism for notification of changes in the scene graph is improved,
• Texture mapping has been tuned and now takes advantage of the OpenGL texture object extension,
• Fields use less memory,
• Picking has been tuned,
• The code for reading ASCII files has been optimized,
• The XtViewers have been overhauled.

In addition to rendering optimizations, Open Inventor 2.1 has some new features as well. There is a new node for locate hightlighting (SoLocateHightlight), a new all-in-one manipulator (SoTransformerManip), and full VRML support (SoWWWAnchor, SoWWWInline, and SoAsciiText).

Open Inventor 2.1 is not binary compatible with the previous release; you will definitely have to recompile your program. You may also have to rewrite some code -especially if you have derived your own custom classes.