Free-form Sketch

We describe a sketch-based system for modeling 3D shapes based on a new multi resolution shape representation we call a layered mesh. Like subdivision surfaces, layered meshes provide a multi resolution hierarchy of meshes. A key difference is that a layered mesh lets you edit the shape and structure of the mesh at any level of the hierarchy, through the notion of shape primitives organized in a dependency network. The simplest primitives are points and curves, which can be used to define several kinds of parametric surface. Surface scan be inflated or smoothly joined to produce a broad range of shapes. An important feature of the system is the ability to refine shapes and add detail by oversketching primitives, either directly or via the curves that define them. While our user interface is still in development, our initial results show the potential for this approach.