BlobMaker: Free form Modelling with Variational Implicit Surfaces

We present BlobMaker, a program for modelling surfaces which uses variational implicit surfaces as a geometrical representation to edit free form shapes. Our approach implements new modelling operations to support stroke (pen-based) input. To this end, we have built a complete modeller application. Users can create and manipulate shapes by sketching on a perspective or parallel view. The main operations are inflate, which creates 3D forms from a 2D stroke, merge, which creates a 3D shape from two blobs and oversketch, which allows users to redefine shapes using a single stroke to change their boundaries or to modify surfaces by an implicit extrusion. We compare these techniques with those of other published approaches. Finally, we describe their implementation in BlobMaker. We have provided additional features such as copying, picking and dragging to offer a natural user interface suitable to free form modelling.