function saveSceneState( scene, state = {} ) {

	state.background = scene.background;
	state.backgroundNode = scene.backgroundNode;
	state.overrideMaterial = scene.overrideMaterial;

	return state;

}
Saves the state of the given scene and stores it into the given state object.

If not state object is provided, the function creates one.

@function
@param {Scene} scene - The scene.
@param {Object} [state={}] - The state.
@return {Object} The state.