Select Twin Edges finds pairs of vertices located very close to each other and selects the edges between them. Twin edges are two separate edges that lie on top of each other: the ends of one edge are very close to the ends of the other, but they are different vertices. They appear along seams where two pieces of a surface touch but are not joined, for example in models built from separate patches or after merging meshes. Use the tool to find such seams before you weld them.
Select twin edges
- Select one mesh in the scene list.
- On the Select tab, open the drop-down arrow next to Select Primitives and choose Select Twin Edges.
- Enter Close distance: vertices located closer than this distance are treated as pairs. The value is 0 when you first open the panel; later it shows the last value you used.
- Click Select.
The panel closes. The found edges replace the current edge selection and are shown as colored lines; the Information panel shows how many edges are selected.
A seam gap is usually much smaller than the edges of the mesh, so start with a small Close distance, well below Avg Edge Length in the Information panel. On the teapot test model, which consists of 19 separate patches, 0.001 mm selects 876 of 9 998 edges along the seams between the patches.
Weld the seams
Use Unite Close Vertices with a similar Close distance: it replaces each group of close vertices with one vertex and joins the patches. To see all open borders of the mesh, use Select Boundary Edges.
