Distorted Surface Near Curves

This has probably been addressed, but could not find a solution in search. I’ve had this problem for 10+ years of SU use.
How do I prevent/get rid of these lines? They don’t seem to be triangles and they are on what seems like a single plane. If I export a 3d model of this, .dxf for example, and then import it back to SU, they show up as dotted lines that I can zoom in and tediously delete and then rebuild the surface from the outer edge. This model will eventually be exported to .stl for wax and bronze casting so I’d like to fix it. See attached PDF of screen shots.


200415 SketchUp Surface Export Problem.pdf (554.0 KB)

Upload the SU model instead of the PDF. It will be easier to understand the issue if you do.

The smooth tool doesn’t smooth anything, it fakes it to look smooth.So an edge creating a 90deg angle as part of a large face has to create the graphic distortions in an attempt to soften/smooth the edge visually. As you found, when you export it other file types think it is geometry and make all the extra edges. But in reality it is only a graphics trick.
You can use round corner or follow me to create an actual rounded edge or hide it rather than soften it. I often fake it by using a couple of extra edges.
In this gif you can see how the whole hole looks strange when you smooth it, but by creating extra edges to contain the distortion it looks much better. I smooth the edge itself and hide the others.


Wow, beautiful work there, you immediately identified the issue. SU is a great tool, but can’t be our only tool in the box I guess. I still love it, though. Since I needed true geometry for a casting, I had a Rhino guy model it for me. Thank you very much for your video.

You could have modeled it in SketchUp with radiused edges.