A system for constructing boundary representation solid models from a two-dimensional sketch

Abstract

This paper describes a system which converts a twodimensional sketch with hidden lines removed of a single polyhedral object into a boundary representation solid model.The system improves on a previous system by Grimstead by analysing the sketch for symmetry elements and regularities. It uses the results of this analysis to produce a more plausible topological completion of the hidden parts of the object, and to enforce exact constraints on the geometry of the boundary-representation model.

Amodal volume completion: 3D visual completion

“…Additional work in 2 1 2 D completion has also been considered in the construction of solid models from 2D sketches [80]. In this work, the Ôfrontal geometry of the 2D sketchÕ (i.e., 2 1 2 D contour sketch) is initially derived from 2D using the techniques of [79].…”

“…In this work, the Ôfrontal geometry of the 2D sketchÕ (i.e., 2 1 2 D contour sketch) is initially derived from 2D using the techniques of [79]. Completion is then performed using geometric face and vertex addition through a method of greedy hypothesis construction and selection.…”

“…Completion is then performed using geometric face and vertex addition through a method of greedy hypothesis construction and selection. In addition, special-case symmetry based completion based on [79] is also considered. This work is, however, limited in its purely geometric view of completion and currently only offers completion of simple 2D geometric sketches consisting of straight lines with right-angled intersections (i.e., block-type objects).…”

“…Some work in this area has been extended to consider detecting 3D symmetry from simple 2D geometric sketches [79]. This work has been further extended to consider 3D completion of these objects [80], but suffers from a number of limitationsnotably its reliance on the simple geometric nature of the sketches it successfully completes and possible ambiguity in interpreting the initial 2D representation (cf., 2 1 2 D completion).…”

3D Sketch: Sketch-Based Model Reconstruction and Rendering

“…However, it is difficult to use for modeling prismatic objects. Varley (2000a) proposed RIBALD, which can convert a sketch to a B-Reps solid model. However, several assumptions must be made about sketches in order for RIBALD to perform this conversion, and thus it cannot directly accept sketch input by designers.…”