Modeling Algorithms

Modeling Algorithms module groups a wide range of topological and geometric algorithms used in geometric modeling. Basically, there are two groups of algorithms in Open CASCADE Technology:

• High-level modeling routines used in the real design;
• Low-level mathematical support functions used as a groundwork for the modeling API;
• Low-level geometric tools provide the algorithms, which:
  • Calculate the intersection of two curves, surfaces, or a curve and a surface;
  • Project points onto 2D and 3D curves, points onto surfaces and 3D curves onto surfaces;
  • Construct lines and circles from constraints;
  • Construct free-form curves and surfaces from constraints (interpolation, approximation, skinning, gap filling, etc);
• Low-level topological tools provide the algorithms, which:
  • Tessellate shapes;
  • Check correct definition of shapes;
  • Determine the local and global properties of shapes (derivatives, mass-inertia properties, etc);
  • Perform affine transformations;
  • Find planes in which edges are located;
  • Convert shapes to NURBS geometry;
  • Sew connected topologies (shells and wires) from separate topological elements (faces and edges).

Top-level API provides the following functionality:

• Construction of Primitives:
  • Boxes;
  • Prisms;
  • Cylinders;
  • Cones;
  • Spheres;
  • Toruses.
• Kinematic Modeling:
  • Prisms - linear sweeps;
  • Revolutions - rotational sweeps;
  • Pipes - general-form sweeps;
  • Lofting.

Shapes containing pipes with variable radius produced by sweeping

• Boolean Operations, which allow creating new shapes from the combinations of source shapes. For two shapes S1 and S2:
  • Common contains all points that are in S1 and S2;
  • Fuse contains all points that are in S1 or S2;
  • Cut contains all points in that are in S1 and not in S2.

  See Boolean Operations User's Guide for detailed documentation.

• Algorithms for local modifications such as:
  • Hollowing;
  • Shelling;
  • Creation of tapered shapes using draft angles;
  • Algorithms to make fillets and chamfers on shape edges, including those with variable radius (chord).
• Algorithms for creation of mechanical features, i.e. depressions, protrusions, ribs and grooves or slots along planar or revolution surfaces.

Please, see the details in Modeling Algorithms User's Guide.

See also: E-learning & Training.