I am working with Vulkan, but would like to know the answer to this question from a general graphics API point of view. Not rasterizing essentially means running only the vertex shader. That means no perspective division or clipping happens, because those sorts of things are done for the purpose of rasterizing (figuring out where/on which pixels/texels a triangle falls). What are the use cases for this? Essentially wouldn't this just mean some sort of program/calculation based only on the vertex input attribute stream, and if that's the case couldn't/shouldn't you just use a compute shader and skip the graphics pipeline?
Is this feature (rasterizer discard) for the ability to be able to the run the graphics pipeline with additional stages such as tessellation and geometry stages, and write to a buffer instead of a render target/framebuffer?