Re-specifying Geometry Canonicity

You can redefine the geometry canonicity and the feature of size to apply the tolerances accordingly.

You can re-define user surface or group of surface properties to avoid recognition problem when selecting a geometry.

Before you begin: Open an existing 3D shape and create an annotation on it.
  1. Right-click the annotation on the 3D shape and select the Associated Geometry > Geometry Canonicity Query and Redefinition.
    • The Geometry Canonicity and Feature of Size dialog box appears.
    • By default, the canonicity is computed from the geometry based on which the situation features, feature of size, invariance class, gender, etc. are computed and displayed.
      Note: You can redefine the gender of the feature without redefining its feature of size.
  2. Optional: To redefine the feature of size:
    1. Select the Redefined check box and select Y from the list.
    2. Specify the gender of the redefined feature as Internal (female) or External (male).
  3. To compute the canonicity and feature of size based on the mathematical definition:
    1. Under the Canonicity section, select Redefined by mathematical definition.
    2. From the Invariance Class list, select the invariance class as Spherical, Cylindrical, or Planar.
      • The canonicity is computed based on the selected invariance class.
      • The situation features, and their position and direction coordinates appear in the dialog box.

        You can modify the position and direction coordinates.

    3. Under Feature Of Size (FOS), select the Redefined check box and redefine the computed gender.

      You can also modify the corresponding feature values, diameter of sphere or cylinder, for example.

  4. To compute the canonicity and feature of size based on the selected geometry:
    1. Under the Canonicity section, select Redefined by geometry and then a point, line, or a plane.

      • Based on the selected geometry, the invariance class appears and the canonicity is redefined.
      • According to the invariance class, the situation features appear with their position and direction coordinates.

    2. Under Feature Of Size (FOS), select the Redefined check box and redefine the computed gender.

      You can also modify the corresponding feature values, diameter of a spherical or a cylindrical canonicity, for example.