Free Friday Tutorial #6: Manifold vs. Non-manifold polygonal geometry
 

YouTube - SimplyMaya Two-manifold vs. non-manifold polygonal geometry

In this video we explain the difference between manifold and non-manifold geometry in Maya, and take a look at the three different types of non-manifold geometry that can occur on your models. We also look at how to detect it and fix it.
The latest free Friday tutorial thanks to Rick :)

Thanks ct and David