I have very little Blender experience, but I would like to know if this is possible.
The ultimate goal is to simulate all areas of a scene that N different "cameras" can see. In this case, these are not Blender cameras, just simulated cameras that have a given angular width and height field-of-view. In this case, I believe using either spot or point lights as "cameras" is the right way to go.
I want to have each "camera" paint all objects in the scene with its own color. Each "camera" will be oriented in a given direction. Objects placed in front of a "camera" will occlude the "camera's" view. I will then be able to determine what parts of the scene are in view of any given camera, and which are not in view. I will be able to see what "cameras" overlap with others, and by how much.
This setup will be used for analysis, not art generation, so it needs to accurately model coverage and "camera" occlusion, but not surface properties, secondary reflections from scene objects, and so on. The scene itself will likely just be flat grey, with some objects placed here and there, plus several "cameras".
I would like to know if this is possible via nodes. I don't want to use any go-between (gobo) geometry to clip the lights into an appropriate angular extent. I am hoping somewhere in my node setup there is an input for field-of-view width and field-of-view height for each "camera", and this determines the extent of the light projected from the "camera".
Alternatively, instead of point or spot lights, it might be more appropriate to use actual Blender cameras, for which one can define the field of view via focal length and aspect ratios, and make a material for all objects that colors them according to "is camera ray", which from my understanding would allow me to paint things a certain color according to whether the camera can see them or not. The problem would then be figuring out how to ensure the objects are colored when in view by any of the N "cameras", as seen from the viewport, or some master camera that sees the whole scene.
Thoughts and suggestions very welcome!