after reading about CSM, I have a few questions about the implementation that I can't find the answer to.
According to the wiki, an FBO can only take 1 depth attachment, so in order to render cascaded shadowmaps in one pass, I would have to use TEXTURE_2D_ARRAY or TEXTURE_3D, correct?
This would force me to use a geometry shader. Would this have a performance hit vs. an alternative method?
The other problem is that I have to define gl_Layer per primative. Could it be possible that a primitive is not fully covered by any single ortho projection? e.g. the camera fov is subdivided, then an ortho projection from the sun is created for each subdivision. If the camera normal is aligned with the sun normal, then the projections' bounds would barely overlap. If a primitive isn't fully covered by either projection, then I can't calculate the depth for that primitive using gl_Layer.