Combine two SFRotation

combine_rotation.wrl

#VRML V2.0 utf8
# (because I always forget the link to my post: http://comp.lang.vrml.narkive.com/RS6A2W0P/add-two-sfrotation-in-js)

Viewpoint{description "A"}

DEF tr1 Transform{
	rotation 0.5 0.4 0.1 2
	children Transform{
		rotation 0.1 0.6 0.3 -0.8
		children DEF obj Shape{
			appearance Appearance{material Material{diffuseColor 0 0 1  emissiveColor 0.3 0 0}}
			geometry Box{size 4 1 2}
		}
	}
}

DEF tr2 Transform{
	children Shape{
		appearance Appearance{material Material{diffuseColor 0 0 1  emissiveColor 0.3 0 0  transparency 0.5}}
		geometry Box{size 5 2 3}
	}
}


Script{
	field	SFNode	tr1		USE	tr1
	field	SFNode	tr2		USE	tr2
	url "javascript:
		function add_rotations(outer_rotation, inner_rotation) {
			var result = new SFRotation();
			var p = new SFVec3f(0, 0, 0);
			var outer = new VrmlMatrix();
			var inner = new VrmlMatrix();
			outer.setTransform(p, outer_rotation);
			inner.setTransform(p, inner_rotation);
			outer.multLeft(inner).getTransform(null, result, null);
			return result;
		}
		function initialize(){
			tr2.rotation = add_rotations( tr1.rotation, tr1.children[0].rotation );
		}
	"
}