Self-Organizing Feature Map (SOFM) based Deformable CAD Models

An adaptive modeling approach that uses a self-organizing feature map (SOFM) to create deformable hexahedral meshes for interactive geometric modeling is presented in this paper. The technique uses the nodes of a three-dimensional SOFM to represent discrete point masses that comprise a solid object. Although the geometry of the resultant mass-spring mesh will change under the influence of inputs applied through a haptic tool and interface, the relative connectivity of neighboring nodes in the time-varying mesh are maintained under the external and internal forces. The initial mesh can either be retrieved from a library of primitive shapes, or created by automatically fitting the topology preserving SOFM to selected surface points. The designer reshapes the virtual object by applying external forces and pressure to the initial mesh. The accuracy of the system depends on the mathematical equations used in formulating the model behavior. The model behavior can be altered by changing the material properties in the underlying mathematical equation. Examples of shape deformation are provided to illustrate the concepts introduced.