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Global and local deformations of solid primitives

Barr, Alan H. (1984) Global and local deformations of solid primitives. ACM SIGGRAPH Computer Graphics, 18 (3). pp. 21-31. ISSN 0097-8930. doi:10.1145/964965.808573.

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New hierarchical solid modeling operations are developed, which simulate twisting, bending, tapering, or similar transformations of geometric objects. The chief result is that the normal vector of an arbitrarily deformed smooth surface can be calculated directly from the surface normal vector of the undeformed surface and a transformation matrix. Deformations are easily combined in a hierarchical structure, creating complex objects from simpler ones. The position vectors and normal vectors in the simpler objects are used to calculate the position and normal vectors in the more complex forms; each level in the deformation hierarchy requires an additional matrix multiply for the normal vector calculation. Deformations are important and highly intuitive operations which ease the control and rendering of large families of three-dimensional geometric shapes.

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Additional Information:© 1984 ACM. I would like to thank Dan Whelan, of the California Institute of Technology, and Olin Lathrop, of Raster Technologies Inc., for technical help with the typography and the illustrations.
Subject Keywords:Computational Geometry, Solid Modeling, Deformation
Issue or Number:3
Record Number:CaltechAUTHORS:20160503-163904118
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Official Citation:Alan H. Barr. 1984. Global and local deformations of solid primitives. SIGGRAPH Comput. Graph. 18, 3 (January 1984), 21-30. DOI=
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:66631
Deposited By: Kristin Buxton
Deposited On:04 May 2016 04:45
Last Modified:11 Nov 2021 00:00

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