Billboard

Billboard Lab

When inside a Billboard node, objects rotate automatically around their axis of rotation in order to face the user.

In the exemple, the trees are only a square with a tree texture, but given you see only the front of it, it looks like it has a depth.
But you could use it for example for an arrow showing the North Pole, or inner-scene 2D advertisements banners in a 3D environment.

Click on the ground for creating new trees.

Billboard enabled:
Wireframe rendering: