Xem mẫu
Solid Modeling Data Structures
Types of Solid Modelers
Constructive solid geometry (CSG) Boundary representation (Brep) Hybrid of CSG and Brep
Categorization based upon way data is stored in database
Constructive Solid Modeling (CSG)
Uses Boolean operations to create complex solids from primitives
Primitives, Boolean operations stored in database
Can make changes to primitives Tree structure
Range of shapes limited (only primitives and Booleans)
Since primitives stored (not surface boundaries), Calculation of NC tool paths for machining is a problem (surface info required)
CSG Tree Structure
Tree structure represents model history
Shows which primitives (leaves) and operations (nodes) were used, and their order
Boundary Representation Modeling
Stores boundaries of solid in database (e.g., vertices, edges, faces)
Similar to surface modeling More difficult to edit once stored
Edge information stored in a systematic way (CCW from outside)
Shading, hidden line removal can be displayed at will
...
- tailieumienphi.vn
nguon tai.lieu . vn