CATIA

This page explains how modifications to parts may affect their persistent ID’s in the CATIA file format.

In most sections below, you will find two tables.

The first set of tables contains two cube images. The left image represents the original, unaltered cube model, while the right image shows the modified instance of the cube model, as described in each section title. The second set of tables provides details on any new or modified persistent ID’s for the model, based on the modified instance described in the section. This includes changes or additions related to faces and edges on the model.

Please note that some sections may not have a second table. However, in these particular cases, context is provided after the initial table.

Adding a loop to a face - Extruding a hole into a cube

In this instance, the part was modified by adding a loop to a face. This is the same as extruding a hole into the cube.

Original Cube Part Modified Cube Part
../../_images/cube_part.png ../../_images/add_hole_cube_part.png
  Faces Edges
New

2 faces with same persistent ID

(CATIA split cylinder)

4 edges
Changes None None

Adding a face to the model - A chamfer

In this instance, the part was modified by adding a face to the model, specifically with a chamfer. A chamfer is a beveled edge that replaces a sharp corner or edge of a part with a sloped surface, typically at a 45-degree angle.

Original Cube Part Modified Cube Part
../../_images/cube_part.png ../../_images/add_chamfer_cube_part.png
  Faces Edges
New 1 face

8 edges (see modified image above)

  • 4 for the chamfer face
  • 4 for the cut edges
Changes None

1 edge is removed

4 edges are cut, so the persistent ID will change

Splitting a face - Adding a groove

In this instance, the part was modified by splitting the a face throughout the model, specifically by adding a uniform groove through the cube, starting from a single face and carrying it through the model’s entirety.

Original Cube Part Modified Cube Part
../../_images/cube_part.png ../../_images/add_groove_cube_part.png
  Faces Edges
New 3 faces

14 edges (see modified image above)

  • 10 for the new faces
  • 4 for the cut edges
Changes 1 face is cut (split) in two. Both have the same persistent ID (see original picture above)

1 edge is removed

4 edges are cut, so the persistent ID will change

Splitting a Cylindrical Surface - Adding a hole through a groove

In this instance, the part was modified by splitting a cylindrical surface through the part that has an existing extrusion. Plainly speaking, this is the same as adding a hole through a groove already existing in the part.

Original Cube Part Modified Cube Part
../../_images/cube_part.png ../../_images/hole_through_groove_cube_part.png
  Faces Edges
New 4 faces, with the same persistent ID 6 edges
Changes None None

ID Uniqueness - Hole repetition

In this instance, the modified part is considered to have a uniqueness of ID’s. The modification example of multiple unique ID’s is achieved by adding multiple hole extrustions in uniform parallel throughout the cube by a single face.

Original Cube Part Modified Cube Part
../../_images/cube_part.png ../../_images/hole_rep_cube_part.png

In the CATIA file format, a hole repetition will create 6 faces with different persistent ID’s (2 faces per hole).

Editing a feature

In this instance, the part was modified by editing a feature. In this particular example, the cube has been transformed into a rectangule.

Original Cube Part Modified Cube Part
../../_images/cube_part.png ../../_images/edit_feature_cube_part.png

In the CATIA file format, editing a feature can change persistent ID’s.

Editing a sketch

In this instance, the part was modified by editing a sketch. In this particular example, the edit was made to the sketch of the cube part model.

Original Cube Part Modified Cube part
../../_images/cube_part.png ../../_images/edit_sketch_cube_part.png

In the CATIA file format, editing a sketch will recompute all of the persistent ID’s.