
If clicking the Repair button for any other option makes your mesh look terrible, you’re likely out of luck.If clicking the Repair button for “Folds on Surface” makes your mesh look terrible, you can skip that one.
One by one, go down the list, clicking Analyze and then Repair if the analysis finds any problems. Select the mesh from the dropdown at the top of the Evaluate & Repair pane. Open the Evaluate & Repair mesh tool (Meshes menu > Analyze > Evaluate & Repair mesh). From the dropdown menu in the top toolbar, choose Mesh design. Import your STL file (File menu > Import > select your STL file). Our conversion tool of choice is FreeCAD because it’s free, relatively simple to use, and does a good job of converting STL files to usable solid models. That being said, if you have no other option, it’s definitely worth a shot! STEP 1: DOWNLOAD A CONVERSION TOOL
If your STL file is of the second type, you won’t be able to convert it. Others are extremely complex, full of holes and have many self-intersections, and will cause the crash of the conversion program. Some of them are low-complexity, watertight, and can be easily converted.