   Texture Grouping? Alpha Blending Speed Ups
  I'm programming an OpenGL particle system which has a lot of alpha blending involved. In a memory/CPU limited environment this will slow down a lot with all the alpha calculations. My attempted to speed it up is to group particles with same properties together into a single texture and render it onto one billboard. But doing so would required dynamic generation of textures and it would require a new glBindTexture for each group of particles. This seems that it might be slower than actually just drawing the particle individually.Are there any other ways to solve this problem using OpenGL?Thanks for any input or commments.   
  Don't try rendering particles onto a single texture automatically.  That won't be faster; blending two particles as you draw them is just as fast as blending them on a separate texture--except now you need to draw that texture to the screen.  This approach is only beneficial if your particles are fairly static and you're updating your "combination-texture"(s) once every dozen frames or so.  For example, I've seen this approach used to render nice clouds.  My suggestions:-just load textures containing a lot of particles on them to begin with-Use point-sprites--saves loads of time in vertex processing.  -Turn off depth writes but not the depth test with glDepthMask(...).  Tweaking this and blending modes works for many applications, and can do away entirely with depth-sorting.  -Use fewer, but larger particles-G   