I am trying to write a fluid simulator that requires solving iteratively some differential equations (Lattice-Boltzmann Method). I want it to be a real-time graphical visualisation using OpenGL. I ran into a problem. I use a shader to perform relevant calculations on GPU. What I what is to pass the texture describing the state of the system at time t into the shader, shader performs the calculation and returns the state of the system at time t+dt, I render the texture on a quad and then pass the texture back into the shader. However, I found that I can not read and write to the same texture at the same time. But I am sure I have seen implementations of such calculations on GPU. How do they work around it? I think I saw a few discussion on a different way of working around the fact that OpenGL can read and write the same texture, but I could not quite understand them and adapt them to my case. To render to texture I use: I am trying to write a fluid simulator that req