Free-form deformation explained

In computer graphics, free-form deformation (FFD) is a geometric technique used to model simple deformations of rigid objects. It is based on the idea of enclosing an object within a cube or another hull object, and transforming the object within the hull as the hull is deformed. Deformation of the hull is based on the concept of so-called hyper-patches, which are three-dimensional analogs of parametric curves such as Bézier curves, B-splines, or NURBs. The technique was first described by Thomas W. Sederberg and Scott R. Parry in 1986,^[1] and is based on an earlier technique by Alan Barr.^[2] It was extended by Coquillart to a technique described as extended free-form deformation, which refines the hull object by introducing additional geometry or by using different hull objects such as cylinders and prisms.^[3]

Applications

• Free-Form Deformation is used in computer graphics for solid geometric models. For example, the Lattice Modifier in Blender (software).
• It is used in the image registration in both rigid and non-rigid transformation.^[4]

External links

• 3D Free-form Deformation
• C++ Library

Notes and References

1. Book: Sederberg, Thomas W.. Parry, Scott R.. ACM SIGGRAPH Computer Graphics . Free-form deformation of solid geometric models. 20. 4. 151–160. 1986. 10.1145/15886.15903. 10.1.1.396.2148.
2. Book: Barr, A. H.. Proceedings of the 11th annual conference on Computer graphics and interactive techniques . Global and local deformations of solid primitives . 18. 3. July 1984. 21–30. 10.1145/800031.808573. 978-0897911382. 16162806 .
3. Book: Coquillart, S.. Extended free-form deformation: A sculpturing tool for 3D geometric modeling . ACM SIGGRAPH Computer Graphics . 24. 4. September 1990. 187–196. 10.1145/97880.97900. https://hal.inria.fr/inria-00075308/file/RR-1250.pdf.
4. http://www.na-mic.org/publications/item/view/903 Nonrigid Registration Using Free-Form Deformations: Application to Breast MR Images