Chris, The approach I took in my particle code (checked into j3d.org) was to *not* dynamically create new particles. This is fairly standard, even with C/C++ particle systems. You can create N particle systems, you can disable/enable them entirely - but you cannot add/remove particles dynamically. This ensures that you don't have to do lots of memory /geometry allocation while the particle system is running. The particles can however be marked as "dead" so that they are (optionally) recycled or not rendered.
The general use case (for me anyway!) is that we want to have a fixed number of particle effects and we need to trade-off accuracy and performance. So on "high" detail we might create 1000 particles for smoke, 500 particles for "mist", 500 particles for "water" etc. etc. You can spawn a new particle system dynamically - when a "rocket" particle collides with a wall you spawn an "explosion" system at the point of collision. Sincerely, Daniel Selman Author - "Java 3D Programming" http://www.manning.com/selman -----Original Message----- From: Discussion list for Java 3D API [mailto:[EMAIL PROTECTED]]On Behalf Of Chris Forrester Sent: Thursday, April 04, 2002 6:20 AM To: [EMAIL PROTECTED] Subject: Best way to go about a resizable TriangleStripArray... Hey all. Foolish me forgot to check the bug parade so I've spent the last day rewriting my particle system to find out why the setValidVertexCount is now only increasing the size of a QuadArray's vertex count, and not decreasing. Seems this is a bug in j3d1.3beta. Anyhow - I'm wondering on the best way to implement this using TriangleFanArray.. setStripVertexCounts requires me to do a (int[])Array.newInstance(int.class, numParticles) and fill for each addition/removal of a particle (though these are batched so creation/deletion of a large number of particles in a single frame only needs to do this once). I'm thinking that a better way to do this would be to simply have the strip index list constantly as large as the initial max number of verticies / 3 (for worse case scenario). Then a setValidStripCount(int numStrips) would be the equivilent of the setValidVertexCount that non-stripped geometry uses. Setting the number of verticies in a given strip then would be provided with get/setStripVertexCountAtIndex(int index) Or is this too complicated and the array newInstance'ing/filling isn't much of a hit at all? ------------------------ Chris Forrester http://www.geocities.com/Psionic81 _________________________________________________________________ MSN Photos is the easiest way to share and print your photos: http://photos.msn.com/support/worldwide.aspx =========================================================================== 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". =========================================================================== 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".
