Quote Originally Posted by pstudio
The rotating as i mentioned is just the general direction of the particle system (modulated by each particles spawn rotation) and not rotating each particle. Rotating each particle gets quite costly.
Well, I was thinking about particle individual rotation, but if it's to expensive I'll have to do without it.
It sadly involves a matrix multiplication per particle, i'm afraid that it would be to much to add in software, the cpu already has alot of stuff to calculate for each particle. Would be another thing putting it into an vertex shader, but then we would be limited to quite modern gpu's.

That and you'll have to add a matrix to each particle, takes alot of memory...

The old version used the texture matrix to spin the textures of the particles per system, it's a ok compromise imo.