Polymend

Reviews a 3D model, repairs the small mesh faults that make a slicer complain (stray triangles, pinholes, reversed faces, split seams), stands it on the bed at the height you ask for, and writes an STL and a 3MF. Shows the model from four sides with every change marked, compares it with the reference pictures, and says what came out well and what did not. Works on GLB and STL files or links, up to 20 at once. Runs on your own computer in the ChatGPT desktop app and Codex (Node.js 20 or later); Polymend uploads nothing.