I've run into the situation where the size of my mesh with all its vertices and indices, is larger than the (optimal) vertex buffer object upper limit (~8MB). I was wondering if I can sub-divide the mesh across multiple vertex buffers, and somehow retain validity of the indices. Ie a triangle with a indice at the first vertex, and an indice at the last (ie in seperate VBOs).
All the while maintaining this within Vertex Array Objects. My thoughts are, save myself the hassle, and for meshes (messes :P) such as this, just use the necessary size (> 8MB); which is what I do at the moment. But ideally my buffer manager (wip) at the moment is using optimal sizes; I may just have to make a special case then.
Any ideas?
Note: I have also cross-posted this on the gamedev stack, as I was not sure as to which it would be more suitable (its partly a design question).
8MB of vertex data is quite a lot for a single model. I'm pretty sure this model could be split into individual meshes. Good places for splitting a mesh are sharp edges, since vertices along these edges have different normal vectors are thus not identical and cannot be shared.
However more important than the VBO size is the size of the render batch passed to glDrawElements (or glDrawArrays). In my experience the optimal size for render batches are between 100 to 2000 triangles, before cache pressure kicks in. But you should measure that on your system yourself.