Doug DeCarlo has developed a new class of parameterized models based on the linear interpolation of two parameterized shapes using a blending function. This blending function describes how the shapes are combined. Using a small number of additional parameters, blending extends the coverage of shape primitives. For example, a bullet shape could be defined by a blend of a sphere and a cylinder. Blends between shapes such as a sphere and torus are also possible, even though they differ topologically. The result would be a shape that has a hole which can appear depending on the blending parameters.
These shapes are incorporated into a physics-based Lagrangian dynamics framework which uses globally and locally deformable models [22]. We can also perform shape morphing, by changing the parameters of an object over time. Since blended shapes have good shape coverage, it is possible to morph between a variety of interesting shapes, including shapes of differing genus. This morphing is tied in with the dynamics, so that forces can arise due to the morphing. These models can also be used in a physics-based shape estimation framework.