Easy way to eliminate unnecesary edges from 3DS / STL import?

Is there an extension or a method of cleaning up the extra edges from 3DS / STL imports?

It adds a lot of extra lines on a perfectly flat face.

They can be cleaned up by hand, but it’s very time-consuming.

Basically, what I have is on the left, what I want is on the right.

Any advice?

Go for the extension “Cleanup3” You will need to fiddle around with it a bit, there are a lot of options but it will get most of the job done.

When you select file/import in Sketchup, just to the right of the format box (where stl is selected), there is an options box. Take that, checkmark on the merge coplanar and attempt to repair checkboxes. That will do it.

However, some stl’s out there just won’t load into sketchup no matter what. In that case, I’ve found that bringing said file into the new Orcaslicer slicer, select and right-click, then take simplify model, set decimate ratio (not much, 1 percent does it) then export back out as an stl, and open in sketchup. It fixes it right up for Sketchup.