One-Sided Surfaces?

[treddie]

Hi again.

Every now and then I run into a problem that I think everyone will recognize in the attached image. It is a case of one-sided surfaces. I encounter these fairly often when working with imported meshes in other programs. The problem here, is that this is occurring in ProE, a solid-modeler. Whenever I run into them in ProE, I have always fixed the problem by changing the part accuracy, although that always seemed like a kludge to me. This time, however, I cannot get the problem to go away. Even if I pubgeom the part as a quilt for another blank file, which has worked for me in the past, as well.

As you can see in the image, the problem is not apparent in hidden line mode. But in shaded mode, the surfaces that would have flipped normals in a surface modeler show up. Because of the problem, I think is why I am having an impossible time of applying a bunch of rounds to the edges in those areas where the problem occurs.

Does anyone know of a way to plan in advance to prevent this from happening? What is causing this? If I take a hint from the surface-modeler world, I would assume that it is a phong shading problem where ProE sees any solid as a closed surface and applies normals that may calculate inverted, causing the renderer to not see those surfaces.

Thank you for any feedback!

 

[treddie]

Well...I found yet another interesting solution. I just starting finding what rounds WERE successful, and eventually by adding enough, the reversed surfaces problem went away. That allowed me to go in and finish up the rounds that weren't possible before.