Recognise
Turns an imported mesh (STL, OBJ, 3MF and others) into a body you can work on: cut, drill, sketch on a face. Click the mesh, choose what to get, Enter.
How
- Press Recognise in the Part bar.
- Click the mesh in the viewport. A second click lets it go.
- In the top bar choose what to get: Exact surfaces or As it is (a polyhedron).
- Tolerance - at the mesh, as a number or a formula. 1 suits a mesh exported from a CAD; a coarser mesh (a scan, a remeshed one) needs more - 10 or 100.
- Simplify, mm - how far the mesh may move from itself to become lighter. A large mesh (from 50 000 triangles) gets the field filled by itself - a ten-thousandth of its size - and the bar warns that the body would be heavy without it. 0 leaves the mesh as it is.
- Enter applies; Esc cancels.
What comes out
- Exact surfaces - planes, cylinders, cones, spheres, tori, the helical faces of a thread, an auger and a spring, and smooth free forms are found on the mesh and the body is built of them. The wall of a hole becomes a cylinder, not dozens of flat strips; a thread's flank becomes one helical face, a spring's wire one face.
- As it is (a polyhedron) - every flat group of triangles becomes a face. Quick and always works, but round stays faceted.
Good to know
- The mesh is consumed. The tree keeps a "Recognised body" node and the mesh leaves the screen. Undo brings it back in one step.
- A click on anything but a mesh picks nothing and says so at once.
- What fits no surface stays as pieces of mesh inside the body. If there are many, raise the tolerance or take As it is.
- The body is slow and takes long to rebuild - the mesh is too fine: every triangle became a face. Undo the recognition and recognise again with Simplify, mm set - 0.01, say: there will be several times fewer triangles, and the shape moves no further than that.
- Only a shell came out, not a body - the mesh has holes or flipped triangles. Try a larger tolerance; if that does not help, As it is gives a polyhedron.