Hi Juan - it does appear to be a problem with the display, not the actual surface.

The mesher for exporting does a more careful job than the display mesher and it is able to display this part of the surface correctly - here I have saved to an OBJ file and set the display option on the Meshing options dialog to Display: Shaded :



So any polygon export, or surface export to .3dm or .igs data will actually have the correct data in it - it is the graphical display that is wrong in this case.

I actually have a shortcut key set up for "SaveAs c:\test.obj", so I can use the export mesher to check if something I see is a display error or actually in the surface.


The groove in this case is created by the position of just one control point in the profile:



In this case the display mesher is kind of missing that groove - if you insert more than one point in that area it will might be able to pick it up and display it a little better.

There will be some things I can do to improve the display mesher, but I have to be very careful not to slow it down as well, so it will take a fair amount of testing work to try and fix this. I will have to save this example off for a while and work on the fix at a later time.

- Michael