This is more of a GPU to CPU question, but I'd like to ask THREEjs people if they have any insights. In summary:
- I have a large mesh requiring GPU calculations.
- After the user interacts with the mesh, the user may elect to export the mesh based on the vertex positions of the GLSL shader (using OBJExporter). These need to be world positions, not screen positions (imagine a 3D print of the model)
I realize that it is expensive to go from GPU to CPU, but can anyone suggest how to do it? I'm not asking for code, but broad ideas would be very helpful as I haven't found much regarding WebGL specific workflows (see here).
How does one get the world XYZ of each vertex in a shader in order to recreate the geometry from the CPU for export?