Provides the content of a [Viewport] as a dynamic [Texture2D]. This can be used to mix controls, 2D game objects, and 3D game objects in the same scene.
To create a [ViewportTexture] in code, use the [method Viewport.get_texture] method on the target viewport.
[b]Note:[/b] When local to scene, this texture uses [method Resource.setup_local_to_scene] to set the proxy texture and flags in the local viewport. Local to scene [ViewportTexture]s will return incorrect data until the scene root is ready (see [signal Node.ready]).