Open CASCADE, the 3D modelling kernel
3D modeling & numerical simulation

Canonical Recognition

NewCastle Software using Canonical Recognition


Canonical Recognition

Canonical Recognition is a non open-source Open CASCADE component to convert, if possible, a NURBS geometry (B-Spline / Bezier curve or surface) to its analytical form (primitive curve or surface).
The component is crucial for algorithms implemented or best fitted to work on canonical geometry. This is especially important in CAM domain for CMM (Coordinate Measuring Machines) and other tooling applications.
The Canonical Recognition component is based on the Open CASCADE Shape Healing module and thereby takes advantage of its powerful capabilities.

The Canonical Recognition component includes :

1. Surfaces and curves simplification for a better reusability in downstream applications. The NURBS conversion depends on the original geometry definition.
NURBS 3D curve can be translated to:
- Line,
- Circle or arc of circle,
- Ellipse or arc of ellipse.
NURBS surface can be translated to:
- Plane,
- Sphere,
- Cylinder,
- Cone,
- Torus.

2. The capability to merge several adjacent topological objects (edges or faces) built on NURBS geometry into one single object based on an analytical geometry. This lowers complexity of the topological model and makes it more usable for other algorithms and, moreover, decreases usage of memory.

3. Tolerance management of the algorithms. The process of Canonical Recognition is handled by user-defined tolerance which is applied for recognition and approximation with canonical geometry.

The conversion preserves topological structure of original shape and thereby retains connectivity of adjacent faces, edges with help of memorizing the history of modifications.

Within applications Canonical Recognition can be optimally used after importing neutral or proprietary files (IGES, STEP, ACIS or others) or in other preparatory modules before using special algorithms.

- Canonical Recognition brings added-value to :
      - Open CASCADE based applications dealing mainly with analytical geometry such as CAM or Metrology applications.
      - Performance and robustness of numeric algorithms (intersection, projection, etc.).
- All information appropriate for canonical geometry (radii, focuses, centers, equations, etc) can be used in applications for display, quick search, statistics and so on.
- The easy-to-use API provides easy integration into existing or new Open CASCADE based applications as a part of CAD data import process or as a new functionality, which can be easily accessible via GUI.
- The demo application visually demonstrating the power of the component is available for Windows NT users.
- No third-party license is required to use this component.

Demo version
You can evaluate the Canonical Recognition component using a free demo.

Please contact us for your free demo and more information and pricing.

This component was successfully applied in a variety of projects, including ActiveX component (Mahr Multisensor) and MIDAS/FX+ (MIDAS IT).


NewCastle Measurement has over 30 years of experience in the CMM industry. We used Open CASCADE Technology and Canonical Recognition - an advanced software component from Open CASCADE Company - as a foundation engine for our NewCastle Off-Line CMM Software, a 3D CAD based system that creates CMM programs from CAD models. Various benefits of OpenCASCADE Canonical Recognition significantly reduced our labor costs in the process of our CMM software development.

Mark Boucher,
NewCastle Measurement


To learn more about this NewCastle Measurement project, please, download a PDF brochure:
New Castle Measurement (567.6K)

© OPEN CASCADE 2000 - 2015  |  Search  |  Contacts   |  Site map