Bad object.. stretched mesh -> black

I stretched an imported model (mesh) and it become all black, I analyzed and it came to be a “bad object”, a friend told me it is because I stretched it over its tangeant radius but I couldnt understand what it means or how I can in the future avoid that.

  • a rendering:

  • in rhino view port:

  • the damaged crane:

pb_black.3dm(152.9 KB)

thanks :smiley:

I think the mesh normals were buggered with the editing.
Select the meshes and run UnifyMeshNormals.
That should correct the viewport display.

1 Like

wow, yes, it worked like magic! :smiley: thanks