Hello everyone. I have one problem with smoothing. My .stl file isn’t smooth. But when something I fon’t know what is done in Blender, the file becomes perfectly smooth. Do you know what exactly is done? I’ll post a picture how the mesh looked after applying some secret tool in Blender. It was very rough before that.
Blenders smoothing tool is visual only - it wont affect how the model exports.
If you want your STL to be smooth, then you’ll need to up the geometry. If the model is Tris, then that might be difficult without remeshing. If it’s Quads though, then you can just add a subsurface modifier, and increase the geometry that way.
If you could describe what you realy want… use it for 3D-print (because it’s a fileformat used for 3D printing).
Or do you just want to imported the STL model and smooth it for rendering? (Then Face → Shade Smooth)… And blender is open source – there are no secrets 
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