Compound feature recognition by web grammar parsing

A method is presented to automatically recognize compound features using web grammar parsing on a solid model graph. A compound feature is a class of regional shapes with a variable topology. Examples of compound features are connected features, which contain a variable number of simple features connected together, and intersecting features, which intersect one another creating different shapes from the original simple features conceived. The simple features are regional shapes related to preestablished application processes. A solid object, stored as a boundary representation, is transformed to a web representation (a node-labeled graph) which is the input of a web parsing system for feature recognition. And a compound feature is described as a web grammar. From the web representation of an object shape, the compound feature recognition can be accomplished by parsing the web with the web grammar. The application of a web grammar enables a user to define a compound feature and makes feature recognition a formalized process for subsequent recognition.