Hi, What is the relation between the window size and the number of fragments being computed? I am writing a pixel shader for particle simulation and I observe that the window size needs to be adjusted depending on the number of particles in the simulation. Suppose, I am simulating it for 500 particles and my window size initially is 128x128. This window size should be sufficient to simulate the process (right) but when I do the simulation, my values are all zeros. However, when I change my window size to some other (bigger size), I find correct simulation results. I want to know how does the number of fragments or particles influences the window size or is it the other way around. Also if someone could elaborate on the reason. Thanks. - FMS