Main geometry types used for solid models
5 main geometry types
- NURBS (boundary representation)
- Spline based description of the surfaces enclosing the volume. NURBS can be used to represent basic algebraic shapes
as well as freeform shapes, such as car bodies
- Sub divisions polygon, subD (boundary representation)
- Polygon (mesh) based description of the surfaces enclosing the volume. The main, coarse, control mesh is automatically
divided into a smother, sub divided final mesh by the CAD tool. SubD is well suited for modeling advanced freeform shapes
- T-splines (boundary representation
- NURBS-based but behaves like subD - easy to convert to NURBS
- Constructive solid geometry (CSG) (direct volume representation)
- Constructive boolean operations on algebraic primitives (volumes), like cones, cylinders, boxes, ...
- Voxels (direct volume representation)
- The solid is represented by a number of smaller 3D boxes (volumes). Like building with LEGO. A voxel may
contain information such as density, doppler data, time ...