Hi Folks,

I'm modeling a flat square grid of weights (vertices) connected by springs. The weights only move vertically. I figured out that the vertical acceleration of each weight is just a Laplacian filter [ [0,1,0] , [1,-4,1] , [0,1,0] ] over the vertical positions. A fragment shader can do that, but how do I get the output (a texture, pbuffer or something like that) back to a vertex buffer? I could (reluctantly) live with copying all the data from one bit of GPU RAM to another, but I certainly don't wanna go via CPU memory. In theory though, I should be able to just cast a single block of physical GPU memory as texture or vertices, shouldn't I? But how?

Thanks in advance,
Adrian.