FIGURES 2–7 in A sketch-based system for modeling 3D objects: Applications to taxonomy

FIGURES 2–7. Creation, visual enhancement and 3D reconstruction. Fig. 2. Strokes: (a) raw stroke; (b) default smoothing applied three times; (c) smoothing applied nine times; (d) oversketching through drawing a new curve near the original one; and (e) replacing the current sketch with the new curve. Fig. 3. Selection operation: (a) cross selection (green) for a closed contour; (b) brush selection (red) by painting the segments belonging to the same contour. Fig. 4. Reconstruction process of a 3D stripe: (a) lines drawn with twist annotation using inverted colors for stripe sides; (b) automatic creation of stripe twists; (c) 3D parametric reconstruction of the stripe. Fig. 5. Sketch inference: (a) triangles created combining points; (b) "headlight beam" effect created by painting triangles according to their angle. Fig. 6. Different depth effects: (a) contours using gray-scale to depict different layers; (b) halo effect; (c) hatching effect; (d) layer coloring from blue to yellow. Fig. 7. Smoothing operations of an open contour. (a) one time; (b) ten times; (c) fifty times; (d) one hundred times; and (e) two hundred times.