Testing for Identical Expressions in a Constructive Solid Geometry System
Original Publication Date: 1988-Sep-01
Included in the Prior Art Database: 2005-Feb-15
A technique is presented for testing two Constructive Solid Geometry (CSG) expressions for identity in which a key is first generated for each expression and then the keys are tested for identity. Two expressions can be identical only if they have the same key. Two expressions may also have the same key even when they are not identical, so a precise test (a verification test) is still required to verify identity. The use of the key, however, reduces the need for verification tests on non-identical expressions to a very small proportion of cases. The key is generated as follows: - Each primitive is assigned a pseudo-random key. The form of the key is not important as long as the same primitive is always assigned the same key.