A Study of the Efficiency of Line Renderings of 3D Shapes

Shape perception depends on a lot of factors, for example texture or shade. When rendering a surface, the question whether the viewer correctly understands the shape of the rendered object is open. The use of different rendering methods can improve or harm shape recognition. This paper presents various styles of line drawings, three traditionally used and a new one, that we describe here, then evaluates their success at conveying the shape of the underlying object. Each line drawing is generated according to simple rules, using geometric properties of the object, for example the normal vector orientation or the principal directions of curvature. An psychophysical evaluation is then performed to compare the various styles. Participants had to adjust a probe until it matches the normal vector they perceived. Results show that the new style that we propose performs better than the principal directions of curvature, for particular cases.