So I've been hammering away at my code for a while, trying to resolve this bug, with absolutely no progress being made.
Mostly due to how utterly random and unpredictable this bug is.
So this is how the scene works when everything is working fine
And when the bug kicks in
As you can see, the bug only prevents my cubemap skybox, model, and light source mesh from rendering, but the orthogonally projected 2d elements are just fine.
I've ruled out shaders, as even the simplest of shader programs still experience this problem. I use ASSIMP to load in mesh files and SOIL to load textures, but up until about a day ago they have worked flawlessly.
There is absolutely no pattern to when this happens, the only way to resolve it is to just keep restarting the program until the desired output appears. That is obviously not a good solution. I'm at a complete loss and need help, as opengl doesn't push out an error or anything. I don't know where to even begin looking for a solution. Could EBO's or frame buffers cause this? As I have started implementing those recently.