Computing Vertex Buffer Object entries in the fragment shader

[cof]

I am working on a morphable model at the moment. I have a dataset of some heads and want to morph between them.
i compute my vertices in the fragment shader (since i have 24 pipelines there) as a linear combination of my datas of the dataset. I write the result in a Vertex Buffer Object, which I received as a sampler2D in my frag shader. I am not quite sure if my Vertex Shader in a second rendering pass has the possiblity to access this data or if I have to pass it pack to the CPU first, what would be kind of a loss since the appropriate data is already in shared memory between vertex and texture memory.

[yooyo]

Readback data into some PBO, then rebind that PBO as VBO and setup vertex pointer. This should work...

yooyo