Deformation Criteria for the Direct Manipulation of Free Form Surfaces
Abstract
The approach proposed here is based on coupling a mechanical model to the input surface geometry provided by the designer. The mechanical model is based on a set of bar networks subjected to tension forces only. Constraints are specified by the designer to express the deformation behaviour of the surface in the area of interest and define functional dimensioning objectives to perform a direct manipulation of the surface. Generally, this process leads to a globally underdetermined system of equations, i.e., the number of unknowns (external forces) is significantly greater than the number of equations generated by the designer's constraints. To this end, a minimization problem is formulated which expresses various deformation behaviours. In contrast to difference of deformation approaches based on mechanical models like membrane models, finite element models, which solely rely on strain energy minimization criteria, the approach proposed here provides the designer various criteria to help him/her create different deformation behaviours like an area minimizing criterion, expressing a minimum change of the shape in the deformed area, expressing a deformation with slowly varying curvature in the deformed area, providing a deformation behaviour which allows to approximately preserve the section of pipe-like surfaces subjected to bending deformations. As depicted, multiple criteria help the designer express various deformation behaviours which are required during a design process.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2000
- Accession Number
- ADP012023
Entities
People
- Jean Claude Leon
- Stephane Guillet