MPhil Thesis Defence


"Ray Tracing of Surfaces of Revolution Using Cone and Revolute Quadric
Subdivision"

By

Mr. Gibson Lam


Abstract

A new algorithm for ray tracing surfaces of revolution is presented. The
objective is to improve the computation cost and data structure during the
intersection calculation of a ray with a surface of revolution. As a
preprocessing step, a surface of revolution is subdivided into a series of
simple surfaces. Our method is tested with two subdivision schemes. In the
first subdivision scheme, a surface of revolution is approximated by
bounded cones. The offset curve of a surface of revolution is subdivided
into linear segments. A series of bounded cones is produced by revolving
these linear segments around the axis of rotation. The second subdivision
scheme uses revolute quadric surfaces to reconstruct a surface of
revolution. The offset curve is approximated by connected conic sections.
These conic sections are converted to a series of coaxial revolute quadric
surfaces by revolving the conic sections around the axis of rotation.
After a surface of revolution is subdivided into bounded cones or revolute
quadric surfaces, a binary bounding volume tree structure is built and
used for finding the intersection between a ray and the surface of
revolution. Calculating the intersection of a ray and a surface of
revolution is then reduced to a simple tree searching with the data
structure. Further reduction of the processing time can be achieved by
using range searching and adaptive bounding volumes for the surfaces.


Date:			Tuesday, 22 January 2002

Time:			10:00a.m.-12:00noon

Venue:			Room 1505
			Lifts 25-26

Committee Members:	Dr. George Baciu (Supervisor)
			Dr. Andrew Horner (Supervisor)
			Dr. Michael Brown (Chairman)
			Dr. David Rossiter


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