stl2step: open-source tool converts STL meshes into STEP solids GitHub user BlinkingSun has released stl2step, an open-source project that converts STL triangle meshes into STEP files containing B-rep solids. It is MIT-licensed, consists of a C++ library and a command-line tool, uses OpenCascade as its geometry kernel and runs on Linux, macOS and Windows. Output is always in millimeters. The program welds vertices, splits the mesh into separate bodies, builds the B-rep geometry in parallel, repairs errors by sewing and merges coplanar triangles into faces. Gaps that cannot be closed are written as an open shell and reported. The default mode, Verbatim, keeps the triangles unchanged, so curves remain many small flat faces. The TrueForm mode detects planes, straight circular cylinders and fillets and reconstructs prismatic 2.5D parts from 2D profiles, with optional DXF export. Cones, spheres, tori and freeform surfaces are not recognized. According to the project, TrueForm detected all 15 cylinders in a CAD export with 908 triangles, with radii deviating by at most 0.3 percent and identical volume. No independent tests exist so far; these figures come from the project itself. The report is based on a single source. Sources: 3druck.com – Programme   submitted by   /u/StoneTimeYT   to   r/MakerNewsEN [link]   [comments]