Using a Point as an Obstruction for Sight Line

[MichaelMcDermott1]

I am trying to figure out how to account for lack of visibility in a camera. So the star below is a camera and the crosses are towers. The circles represent what area my camera can see. I need to remove from this circle the spots behind the towers that my camera cannot see. It would be roughly one degree. What is the best way to do this? I have tried a lot of different ways and did not seem to get the desired result.

[DanPatterson_Retired]

buffer the points to make them polygons?

[DuncanHornby]

It is not clear what you are asking, you define the star as your camera, the circle the limit of what the camera can see and the crosses are towers then you say:

I need to remove from this circle the spots behind the towers that my camera cannot see

What are the spots? What do those two blue lines meant to be? How are you defining "behind".

You need to amend your question and make it clearer in what you are asking.