7. The method of claim 1 , wherein a position of the element in scene space is definable by: a first link located between a base joint of the element and a middle joint of the element; and a second link located between the middle joint and a tip point of the element.
8. The method of claim 7 , wherein moving the element comprises: determining a set of candidate positions for which a projection of the base joint onto screen space is located at the starting point or the ending point of the stroke, and a projection of the tip joint onto screen space is located at the starting point or the ending point of the stroke; and selecting a candidate position from the set based at least in part on the direction of the stroke.