Godot: Add a way to directly perform a Raycast from a Camera

[aaronfranke]

Godot version: 3.0.5 +

https://godot.readthedocs.io/en/latest/classes/class_camera.html

The Camera node has some methods for assisting with projecting rays, but none of these methods actually perform full Raycasts. I think it would be useful to have a method which returns a RayCast object containing a RayCast from the mouse position on the screen into the world. That way, I could, for example, simply run get_collision_point() on that returned RayCast object to figure out the 3D point on a CollisionShape in the world that the camera is pointing at.

[Zylann]

Why not just:

• Putting a RayCast node as child of the camera pointing forwards?
• Or doing the raycast via code using space_state.intersect_ray, -transform.basis.z or projection with a few lines of script?

I don't think physical raycasting should be part of a Camera node when it can be so easily done with a simple setup.

[pgruenbacher]

https://godotengine.org/qa/1996/ray-casting-from-the-camera-in-3d

also input_ray_pickable may also help if you're trying to pick objects from your camera and mouse.
http://docs.godotengine.org/en/3.0/classes/class_collisionobject.html#member-variables