Reference Plane Assisted Sketching Interface for 3D Freeform Shape Design

This paper presents a sketch-based modeling system with auxiliary planes as references for 3D freeform shape design. The user first creates a rough 3D model of arbitrary topology by sketching some contours of the model. Then the user can use sketching to perform deformation, extrusion, etc, to edit the model. To regularize and interpret the user´s inputs properly, we introduce some rules for the strokes into the system, which are based on both the semantic meaning of the sketched strokes and human psychology. Unlike other sketching systems, all the creation and editing operations in the presented system are performed with reference to some auxiliary planes that are automatically constructed based on the user´s sketches or default settings. The use of reference planes provides a heuristic solution to the problem of ambiguity of 2D interface for modeling in 3D space. Examples demonstrate that the presented system can allow the user to intuitively and intelligently create and edit 3D models even with complex topology, which is usually difficult in other similar sketch-based modeling systems.