The “non-manifold edges” warning in Orca
A model’s surface must form a closed shell: every edge must be shared by exactly two triangles. If an edge belongs to a single triangle (an open edge) or to more than two, the slicer shows the “non-manifold edges” warning.
Why does it happen?
- Micro cracks and surfaces that do not meet exactly, created during scanning or conversion, produce open edges.
- Two parts touching along the same edge (copied or merged models) split one edge into four: four triangles share the same edge.
- Zero-area (degenerate) and duplicate triangles are counted too.
- The problem is usually in the source model; format converters do not change mesh data.
How to fix it
- Drop the file onto the Model Repair tool (3MF or STL): the scan shows the number of problem edges per object.
- Press “repair while keeping colors” (the button is in Turkish: “Renkleri koruyarak onar”); the tool fixes only the problem edges, and per-triangle paint and project settings stay as they are.
- Open the repaired file in Orca and check that the warning count has dropped. On very complex self-touching surfaces a few edges can remain.
Frequently asked questions
Should I use Orca’s own “Repair” button?
On Windows that button calls the system’s 3D repair service; it rebuilds the mesh, so color painting can be lost. For colored models try Model Repair first.
Is the file uploaded to a server?
No; scanning and repair run in your browser.