Geometric models are the basis of all modern computer-aided design and manufacturing systems. They are created and maintained by programs that allow three-dimensional shapes to be represented in the computer.
In addition to storing shapes, we want such programs to be able to compute:
1. Volume
2. Mass
3. Surface area
4. Moments of inertia
5. Strength
6. Flexibility
7. Heat and fluid flow
8. Mechanical integrety and fit
9. Automatic manufacture, and
10. Pictures
Items 1 to 4 are called integral properties; items 5 to 7 imply links with finite-element and computational fluid dynamics software; item 9 is an artificial intelligence problem that has only partly been solved; item 10 is useful for product advertising, visualization for manufacture, and simply checking that the model is correct. Details of how pictures of solid models are created will be given as the course progresses, and all the other items are covered in specific lectures.
Geometric modelling software must give us models that are:
1. Accurate
2. Unambiguous
3. Compact (don't use much computer memory or disc)
4. Fast (can be computed quickly), and
5. Useful (see the list above)
What on earth does this mean?
This makes much more sense:
The world is three-dimensional. Why throw one away?
Automation of just about anything needs that unambiguous.
© Adrian Bowyer 1996