I need to know if a pixel is visible to a particular camera. I don't need to know if it's blocked by another object (as is the case in this answer), so I'm thinking the answer might be simpler. For instance, if I have a point in my scene and a Camera 2, is there a way, in a Python script, to tell if that point is visible to Camera 2?
I'd also settle for what seems a converse of this, if I could find what the boundaries of the camera's view area is at a particular distance from the camera, then I could easily use that to create a plane and see if a particular point or pixel is in that plane.