Line direction matters: an argument for the use of principal directions in 3D line drawings

While many factors contribute to shape perception, psychological research indicates that the direction of lines on the surface may have an important influence. This is especially the case when other techniques (shading, silhouetting) do not present sufficient shape information. The psychology literature suggests that lines in the principal directions of curvature may communicate surface shape better than lines in other directions. Moreover, principal directions have the quality of geometric invariance so line directions are based on the surface geometry and are viewpoint and light source independent, and the lines do not move above over the surface during animation unless desired. In this work we describe principal direction line drawings which show the flow of curvature over the surface. The technique is presented for arbitrary surfaces represented by either 3D volume data or a polygonal surface mesh. The latter format is common in the field of computer graphics yet thus far has not ...

• Type: Conference
• Year: 2000
• Where: NPAR
• Authors: Ahna Girshick, Victoria Interrante, Steven Haker, Todd Lemoine
• Keywords: Computer Animation, NPAR 2000, Principal Direction, Principal Direction Line, Surface Shape