Defining a vision cone in unity

Question

I am attempting to implement a boids flocking model in unity.

I have managed to implement steering behaviors (separate, align, cohere) but I am currently using a fixed radius from the agent to define its neighborhood (essentially a bubble around the agent). However, what I need to implement is a vision cone like the one detailed in this image:

I'm unsure how I could implement this in unity. Could someone point me in the correct direction?

To add clarity, what I want to do is detect all other agents in a vision cone, but I'm unsure how to implement it. Currently, I am just detecting all agents within a distance, though I need to ignore the agents behind the one doing detecting ( like in the picture) I'm not looking to visualize it, just detect the agents in that defined neighborhood.

thanks

Answer 1

First, detect all the agents in the circle, then check for every one of those the Vector3.Angle() between transform.forward and the direction to the agent. (as the direction from vector A to B is just B to A).