Trigger adjustable to camera view frustum

Hi!

I would like to know how I can make a trigger that adjusts its size to what the camera sees, or failing that, something very similar to the “Draw Debug Focus Plane” that cine cameras have. That the trigger is adjusted from the camera position to a plane that varies both in width / height and depth.

I have tried to set the extent of a child trigger of the camera, according to the bounds of the plane (that I control), but I can’t get it to work correctly. Any ideas / help?

Thank you!