CS 460 Computer Graphics

Solids

Solids should possess the following characteristics to be effective:

  1. Produce unique results
  2. Have an unbounded domain
  3. Render the object with accuracy
  4. Efficient use of both time (computation) and space (storage)
  5. Able to combine with other objects to form more complex ones

The methods to create solids are:

Primitive Instances
Specific solids are generated by a program

Sweep
A 2D (read flat) area is swept into a volume by linear and/or rotational motion

Boundary Representation or B-rep
A solid is represented by its surface using poly meshes or bicubic patches, no interior

Spatial Partitioning
Fill a volume with a single basic primitive, usually small spheres

Constructive Solid Geometry or CSG
Extended primitive instances along with user defined primitives

Boolean Operations are additive operations performed on solids generated using one of the above methods. Remember that "not" primitives can be added to provide holes.

Here are how the various methods stack up wrt to our requirements:

MethodUniqueDomainAccurateEfficientCombine
Primitive InstanceYESVery LimitedYES
Very Accurate		YESNO
SweepYESLimitedYESYES
Best at both		NO
B-RepsNOYESYESDriven By
Complexity		YES
Spatial PartitionsYESYESMore Accuracy With
Small Primitives		Inverse Of
Accuracy		YES
CSGYESLimitedYESImpacted by
Domain		YES
Main Feature

Detailed notes in pdf format (145 KB)

G. Hill Price