Figure 1: Our analytic drawing tool infers 3D scaffolds of linear segments (a) from sketched strokes. 3D feature curves can then be sketched by deriving position and tangent constraints from the scaffold (b). After fixing the viewpoint and adding image-space silhouette curves (c), we apply traditional hand-rendering techniques [Robertson 2003 ] to create a production design drawing of the espresso machine (d). We describe a novel approach to inferring 3D curves from perspective drawings in an interactive design tool. Our methods are based on a traditional design drawing style known as analytic drawing, which supports precise image-space construction of a linear 3D scaffold. This scaffold in turn acts as a set of visual constraints for sketching 3D curves. We implement analytic drawing techniques in a pure-inference sketching interface which supports both singleand multi-view incremental construction of complex scaffolds and curve networks. A new representation of 3D drawings is proposed, and useful interactive drawing aids are described. Novel techniques are presented for deriving constraints from single-view sketches drawn relative to the current 3D scaffold, and then inferring 3D line and curve geometry which satisfies these constraints. The resulting analytic drawing tool allows 3D drawings to be constructed using exactly the same strokes as one would make on paper.
Schmidt et al. REF present a pure-inference interface for 3D lines and curves from single-view sketches.
Analytic drawing of 3D scaffolds
SIGGRAPH Asia '09
Computer Science