Robust sculpting using boundary represented solids
Boolean operations are often used in the computer modeling of 3-D mechanical parts and machineries and are known for their predictable behavior and ease of use. The use of Boolean operations in the interactive modeling of free-form models, however, has been rather limited. Some of the difficultie...
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| Language: | English |
| Published: |
2009
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| Online Access: | http://hdl.handle.net/2429/10705 |
| Summary: | Boolean operations are often used in the computer modeling of 3-D mechanical parts
and machineries and are known for their predictable behavior and ease of use. The
use of Boolean operations in the interactive modeling of free-form models, however, has
been rather limited. Some of the difficulties in realizing this include: selecting a model
representation that may be displayed at interactive speed, applying Boolean operations
robustly, and creating smooth surface transitions at the junctions between models.
This thesis explores the use of the real number package of the Library of Efficient
Datatypes and Algorithms (LEDA) for computing the Boolean combination of triangulated
and boundary-represented solids robustly. This thesis also suggests a scheme for
removing numerically unstable triangles which are detrimental to the validity of solids,
and a surface blending scheme that simulates the smoothing of sharp surface junctions
by modifying surface normals. Our scheme for computing Boolean operations is more
robust than those used in two popular modeling applications but at the expense of longer
computation time. Our scheme for removing numerically unstable triangles is effective
in removing invalid surface triangulations while preserving the appearances of models
and our simulated surface blending scheme is capable of smoothing non-trivial surface
junctions at near-interactive rates. These features were implemented in a simple solid
modeler and a set of models was created interactively using this system. |
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