> >I just wanted to say that i've gotten a 1.2.1 particle system working 
that uses
> a giant QuadArray and BY_REFERENCE members for quick insertion/removal.
> >
> >Particles are defined as quads with their own offset transforms (for
> scaling/rotation/position offset) and hook into a simple
> position/direction/lifetime particle movement system. These quads all 
share
> Appearance data as well, so you can create alpha/additive textures and 
apply
> them the object to get cool particle effects.
> >
> >For numbers, I can get decent performance with (tested so far) 400 
particles on
> the screen (with one texture unit) at once. This totally blows away the 
other
> method I've tried for a system, which was individual TriangleStripArray's 
per
> particle. With that system, I capped out at 40.

Chris � what O/S, what kind of CPU, and what kind of graphics card are 
you using?
I ask because this doesn't sound like it is very fast. What kind of 
"physics" calculations are you applying to each particle.

FWIW I managed to get 5000 thousand particles at 50fps+ using a GeForce 3 
and Pentium 4 1.7GHz) and Java3D 1.2.x. This is with simple physics only 
� i.e. bouncing off a single floor plane � but everything is 
parameterised and flexible.   I don't have per-particle transforms (i.e. 
per particle rotation) built in.

Please don't think I'm bragging with this � I'm just curious as your 
approach sounds similar to mine and our results very different, so I 
guess yours are much more sophisticated than mine in the math department.

What I have done with mine is take extreme care � there is never any 
memory allocation at all while the particle system is running. I'm not 
using byRef geometry in the example I cited � perhaps that's it. My 
system has the geometry writing abstracted so byRef can be done, but I 
guessed that not using byRef is faster and I don't care about memory at 
the moment. Other aspects are abstracted too, and this doesn't seem to 
add a major performance hit.

The above figures are for particles composed of 2 triangles, with a 
single alpha-blended texture being used. 

Marc

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