I have a 3D world with some model in it (the XZ-plane grid, some gray boxes and a red box). In the upper-left corner I'm trying to draw a minimap that should represents the whole world in 2D (flat). As you can see I already achieved to draw the grid and the boxes just using their scaled position. With the same logic I drew the camera too so here's my question: how can I draw the "cone" of view for this camera? In the image below I just drew a green shape that should explain what I mean better than words (obviously the green one in the image doesn't represent the actual view for this camera, it's just an example).
I'm using LibGDX with a PerspectiveCamera so I got access to all the camera information like the fow, the frustum and so on. Any idea how to implement this?