A SKETCH INTERPRETER SYSTEM WITH SHADING AND CROSS SECTION LINES BY FREEHAND DRAWING

摘要

We present a sketch interpreter system with shading and cross section lines for 3D freeform design. The input strokes are classified into three types: outline (contour line), shading line and cross section line. The outline is used to generate the basic rounded shape. The shading lines and cross section lines are used as control lines which are drawn inside the contour for modifying the 3D, shape. In order to extract the 3D information from the shading and cross section lines effectively, we analyze the different representations and deformations of the shading and cross section lines and classify them into three cases: convex, concave and upheaving. Each deformation is drawn by hand and transferred to 3D shape according to the rules proposed in this paper. We evaluate our sketch interpreter system for various objects from the concept sketch and present our results.