Hi Burr, it looks like your CAM package is taking the center of the underlying surface as the spot for displaying the normal.

In MoI, select that face and do an Edit > Separate to break it off of the main object, and then use Edit > Show pts to turn on control points and you will see that underlying surface is a kind of slanted parallelogram, the visible part is half of the underlying surface and the centroid point of the underlying surface is in that spot that you indicate.

That surface probably started out as a longer piece and the current one you see is the result of some other trimming or booleans that cut it in half diagonally.

- Michael

Yes, Mr. Gibson, I'm good now. Thanks again.

The piece of this model started life as part of a VRML file. I used Rhino to convert it to a series of lines, then used Rhino's mesh to polysurface command, then saved that as a 3DM file and used MoI for cleanup and enhancements.

So, it was probably related to the Rhino polysurface command. Or was it polymesh? Can't remember.

Hi Yenmonger, yeah probably Rhino's MeshToNurb command created that triangle that is half of a parallelogram. But there is nothing wrong with that.

I'm going to see if I can narrow down where in the inside/outside detection mechanism that things are going wrong and send this to the company that makes the geometry library so that it might get improved for v3.

- Michael

Hi Yenmonger, just a note on this - I was able to track down the bug in the geometry library that was making the inside/outside detection mechanism get confused for this case and I think that the fix is simple enough that I will include it for the v2 final.

- Michael

Neat, thanks!