Flexible particles

If prims can be displayed in a soft flowing manner as flexi-prims, why not add similar code to the display of particles?

This is making me remember an old suggestion for two dimensional prims.

Seems like an interesting idea. However, it should be made an option that can be toggled on and off so that the people in SL with so-so video cards can disable it.

Coming from someone that's worked with OpenGL before, I'd assume because they're not really the same thing.

Flexiprims appear to be a hack with OpenGL's tri and quad buffers with a good deal of verts to work with. By contrast, particles *should* be just four-sided GL quads in 3D space.


To get the effect you're mentioning, you'd require each particle to have exponentially more quads, dropping the number of particles you can display to a small fraction of what we can now.

That's not a really good way to do it.


However, what could forseeably happen is if LL impemented llSetTextureAnim on particle surfaces. Since that already happens when you play a movie on a particle texture (due to how GL buffers work), I suspect a similar effect wouldn't be difficult. Provided they have the volition to do so.

I would be happy if the particles emitting point was moving too when flexiprim moves. As it is now it's stuck in the center of the non-flexi version of the prim

I was just thinking along those lines, in a less knowlegeable manner.

Do that, and add in the ability to have static arrays of particles.

I think static arrays of particles that can have animated textures on them would add a good bit of display capability for a low price in use of resources.

I recall seeing some exposion particles with the media display texture on them showing the badger badger video. The importance of more efficient dancing badger display techniques cannot be overemphasized.

Up above I said cannot. Should've said should not.

Hmm, hadn't tried or even thought about that at all - good point.

Animated particles would be pretty sweet actually. But im not sure of the impact it would have on performance. Each particle would be displaying diffrent frames a diffrent times. I would imagine the frame would depend on the particle age. Dono if the texture coord switching is very expensive or not?

I suppose we would need to 'vote' on it to be considered.
But I think it would be super.

Geometry in SL works because you can express a prim as a formula, so it can be transmitted as a few bytes very quickly. Flex prims are prims whose equations can be tweaked a bit to modify the volume the prim represents.

Particles, though, are really just clusters of individual free-floating vertices that have visible properties assigned to them, and have a whole extra set of particle properties that makes them behave that way. They have no group identity, so you can't modify them the way you can a prim. In essence, they're preprogrammed, and once launched, they live out their lives, express their properties and die with no possibility of external control.

Don't look for "flex particles" any time in the near future.