>Date: Tue, 04 Jun 2002 00:08:38 -0400 >From: David Yazel <[EMAIL PROTECTED]> >Subject: [JAVA3D] USE_COORD_INDEX_ONLY >To: [EMAIL PROTECTED] >MIME-version: 1.0 >X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 >Content-transfer-encoding: 7bit >X-Priority: 3 >X-MSMail-priority: Normal >Delivered-to: [EMAIL PROTECTED] > >Docs Say: "Specifies that only the coordinate indices are used for indexed >geometry arrays. In this mode, the values from the coordinate index array >are used as a single set of index values to access the vertex data for all >four vertex components (coord, color, normal, and texCoord). The color, >normal, and texCoord index arrays are ignored. This flag is only valid for >indexed geometry arrays (subclasses of IndexedGeometryArray). " > >Kelvin Says: > >Using the flag USE_COORD_INDEX_ONLY in vertexFormat will prevent Java3D >unindexify the array before passing down to OpenGL/D3D > >Some questions: >1. Is this the only condition where indexed geometry gets sent to the card >in this format?
Yes. Prior to v1.3 we always unindexify geometry before passing down to OGL/D3D. >2. If you have a tremendous ratio of shared vertices (like 5-1) will the >speed of rendering be substantial? It depends on the vertex coherency, newer card has a special vertex cache to take advantage of it. >3. Is this supported fully in both opengl and directx? Yes. >4. Do you no longer need to fill in or allocate the other indexes? (color, >normals, etc) Yes. only one index is needed as doc. mention. for USE_COORD_INDEX_ONLY. >5. How have people found the performance of using indexed arrays? > It is up to the underlying OGL/D3D implementation. - Kelvin ------------------ Java 3D Team Sun Microsystems Inc. =========================================================================== To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message "signoff JAVA3D-INTEREST". For general help, send email to [EMAIL PROTECTED] and include in the body of the message "help".
