Check Shape Validity in FreeCAD Part Workbench

Ensuring that a 3D model is geometrically valid is critical in FreeCAD before performing boolean operations, meshing for finite element analysis, or exporting for 3D printing. Invalid shapes often contain self-intersecting faces, non-manifold edges, or degenerate geometry that can cause modeling operations to fail silently or crash the software. This guide covers how to utilize the native verification tools available in FreeCAD's Part workbench to inspect, detect, and diagnose geometry errors efficiently.

1. Switch to the Part Workbench

To access the shape inspection tools, you must first switch to the proper environment:

  1. Open your model in FreeCAD.
  2. In the workbench selector dropdown menu at the top of the interface, select Part.

2. Select the Target Shape

In the Tree View (Model tab), click on the shape, body, or feature you wish to evaluate. Ensure only the intended object is highlighted so the tool evaluates the correct solid or surface.

3. Open the "Check Geometry" Tool

With the object selected:

  • Go to the top menu bar and click Part → Check geometry.
  • Alternatively, click the Check geometry icon (a green checkmark over a blue cylinder and cube) on the Part toolbar.

4. Configure the Inspection Settings

The "Check geometry" task panel will open on the left. Before running the check, you can configure the depth of the analysis:

  • Run BOP check: Check this box to enable the Boolean Operations Component (BOP) check. This runs an advanced algorithm from the OpenCASCADE technology kernel to detect complex topological faults, such as self-intersections and tangency conflicts between faces.
  • Log errors: Ensure this is checked so that specific geometry errors are output with details.

5. Run the Check and Analyze Results

Click the Run check button in the task panel. The results will populate in the dialog:

  • Valid Shape: If the model is error-free, the list will indicate that the shape is valid with no errors detected.
  • Invalid Shape: If issues are found, the panel displays a hierarchical tree of faults (e.g., Self-intersecting wire, Face not closed, or Degenerated edge).
  • Highlighting Errors: Clicking on an error entry in the results tree highlights the problematic edge, vertex, or face in red in the 3D viewport, allowing you to pinpoint exactly where the geometric failure is located.

6. Exporting or Copying Diagnostic Data

If you need to review the errors further or report a bug, click the Save to file button or copy the output text directly from the panel. This log contains the OpenCASCADE error codes and specific topological sub-element IDs that need remediation.