A sketch-based user interface for reconstructing architectural drawings

We present a framework for interactive sketching that allows users to create three-dimensional (3D) architectural models quickly and easily from a source drawing. The sketching process has four steps. (1) The user calibrates a viewing camera by specifying the origin and vanishing points of the drawing. (2) The user outlines surface polygons in the drawing. (3) A 3D reconstruction algorithm uses perceptual constraints to determine the closest visual fit for the polygon. (4) The user can then adjust aesthetic controls to produce several stylistic effects in the scene: a smooth transition between day and night rendering, a horizon knockout effect and entourage figures. The major advantage of our approach lies in the combination of perception-based techniques, which allow us to minimize unnecessary interactions, and a hinging-angle scheme, which shows significant improvement in numerical stability over previous optimization-based 3D reconstruction algorithms. We also demonstrate how our reconstruction algorithm can be extended to work with perspective images, a feature unavailable in previous approaches.