CAD Import Process

CAD import occurs in three steps: (1) pre-processing, (2) conversion from a third-party format to Parasolid where applicable, and (3) post-processing of the Parasolid model.

1. Pre-processing

Format Description
Parasolid Parasolid is used for pre-processing .x_b, .x_t, .xmt_bin, and .xmt_txt models.
JT JTOpen is used for pre-processing .jt models.
CT XT-based CAD formats (SW, NX): These formats don't require pre-processing by the CoreTechnologie KERNEL_IO.
Non XT-based CAD formats: CoreTechnologie KERNEL_IO is used for pre-processing non XT-based CAD formats. The CT model is prepared as follows:
  1. (Optional) Healing (also known as Pre-healing): Check each part and only heal when necessary, based on a given tolerance. The tolerance is calculated separately for each part, based on the size of the part's bounding box.
  2. Pre-conversion: CT geometry is modified so that parts can be converted to Parasolid.

2. Conversion from a Third-Party Format to Parasolid (Where Applicable)

Format Description
JT JTOpen provides direct conversion to Parasolid parts.
CT XT-based CAD formats (SW, NX): Parts don't need to be converted to Parasolid, as the CT model provides XT blocks containing the Parasolid parts.
Non XT-based CAD formats: The CT model is converted as follows:
  1. CT faces and edges are converted to Parasolid.
  2. The curves of edges are used to trim the surfaces of faces to obtain Parasolid faces.
  3. The Parasolid faces are knitted to obtain Parasolid parts. If knitting partially or completely fails, additional sewing may be performed.

3. Post-processing of the Parasolid Model

Parasolid parts are checked for valid geometry.

Important: Before importing CAD, turn on the ability to run diagnostics in the Preferences:
  1. On the File menu, click the Preferences button to open the Preferences window.
  2. Under Category, select Inspire > Geometry.
  3. Under Preference, scroll down to Import from CAD File.
  4. For Fast import, select With diagnostics.
Once you turn on With diagnostics, you have the following post-processing options:
Option Type Description
Solidify Post-processing When there are issues such as gashes, small missing faces, sliver faces (faces that were deleted because they were non-tessellated), you can turn on this option to help make parts solid.

When tessellation partially fails, non-tessellated faces are deleted and the Solidify operation is performed again.
Reset Edge Precision Post-processing Recalculate the tolerant edge geometry to improve precision.

While turning this option may not topologically or visually modify the part, it may fix some failing modeling operations.
Note: Solidify and Reset Edge Precision are the only post-processing options relevant to XT-based CAD formats (Parasolid, JT, SW, NX). Since XT-based CAD parts don't need to be converted to Parasolid, Healing (aka Pre-healing), Alternate Convert, and Sewing aren't applicable.