Implementing agent visibility begins with casting a number of raycasts into the sandbox to see whether the agent can visibly detect another agent without objects blocking our agent's sight. To cast a ray, the only requirements are a starting and ending point within the sandbox. The results of the raycast are returned as a Lua table that contains a result attribute indicating whether anything was hit; it also contains an optional object attribute of the sandbox object that the ray intersected with, if the raycast successfully intersected with an object.

To case a ray we'll use the RayCastToObject function provided by the sandbox.

local raycastResult = Sandbox.RayCastToObject(
    sandbox, startPoint, endPoint);

In the following screenshot, you can see various rays that represent agent visibility...