ShapePalettes: interactive normal transfer via sketching

We present a simple interactive approach to specify 3D shape in a single view using "shape palettes". The interaction is as follows: draw a simple 2D primitive in the 2D view and then specify its 3D orientation by drawing a corresponding primitive on a shape palette. The shape palette is presented as an image of some familiar shape whose local 3D orientation is readily understood and can be easily marked over. The 3D orientation from the shape palette is transferred to the 2D primitive based on the markup. As we will demonstrate, only sparse markup is needed to generate expressive and detailed 3D surfaces. This markup approach can be used to model freehand 3D surfaces drawn in a single view, or combined with image-snapping tools to quickly extract surfaces from images and photographs.