Append a glTF2 3d format from a file, buffer or scene and then write to the filesystem, buffer or scene. Takes a [PackedByteArray] defining a gLTF and returns a [GLTFState] object through the [param state] parameter. [b]Note:[/b] The [param base_path] tells [method append_from_buffer] where to find dependencies and can be empty. Takes a path to a gLTF file and returns a [GLTFState] object through the [param state] parameter. [b]Note:[/b] The [param base_path] tells [method append_from_file] where to find dependencies and can be empty. Takes a Godot Engine scene node and returns a [GLTFState] object through the [param state] parameter. Takes a [GLTFState] object through the [param state] parameter and returns a gLTF [PackedByteArray]. Takes a [GLTFState] object through the [param state] parameter and returns a Godot Engine scene node. Registers this GLTFDocumentExtension instance with GLTFDocument. If [param first_priority] is true, this extension will be ran first. Otherwise, it will be ran last. [b]Note:[/b] Like GLTFDocument itself, all GLTFDocumentExtension classes must be stateless in order to function properly. If you need to store data, use the [code]set_additional_data[/code] and [code]get_additional_data[/code] methods in [GLTFState] or [GLTFNode]. Takes a [GLTFState] object through the [param state] parameter and writes a glTF file to the filesystem. [b]Note:[/b] The extension of the glTF file determines if it is a .glb binary file or a .gltf file.