   MRT and GLSL
  Hi,   I have been away from OpenGL and I'm revisiting a fluid sim I wrote using OGL 2 and GLSL. Back then I was using the framebuffer and the ping pong technique, which works fine, but to optimize and make the sim faster, it would be great to be able to render out more than one texture from the shaders. I started reading about MRT and gl_FragData, but then discovered that glFragData has been deprecated and the 'out' statement is used. Are there performance gains in using OGL3 and GLSL 1.5 vs using OGL2 and GLSL 1.2 (i think that's the right version)? Is it easier to do MRT with OGL3 since the FBO extensions are built in? Finally are their any good tutorials on doing FBO, MRT in OGL3? Thanks!   