Differential-Based Geometry and Texture Editing with Brushes

We present an interactive modeling framework for 3D shapes and for texture maps. The technique combines a differential-based deformation method with the idea of geometry brushes that allow to interactively apply modifications by painting on the geometry. Whereas most other deformation techniques demand the designer to define and move hard constrained regions on the surface, the proposed modeling process is similar to sculpting.Geometry brushes allow the user to locally manipulate the metric, enlarge, shrink or rotate parts of the surface and to generate bumps. In a similar way it is possible to modify texture maps, or more generally, arbitrary tensor maps on surfaces. The local modifications of the surface are integrated to a globally consistent deformation and visualized in real-time.While the geometry brushes are intended for local editing, the underlying technique can also be applied globally. We show how differentials may be modified for creating specific effects, like cartoonization of shapes or adjusting texture images.