You can make smooth patches from rough polygons automatically by setting a patch in the property of the object panel. There are three types of a patch in this version.
When you use [Spline Type 1] and [Spline Type 2], polygons must be quadrangles only as a general rule. A triangle can be mixed, but it must be surrounded by three quadrangles. A hole opens if the neighboring face of a triangle is triangle or there is no face next to it. As two triangles can be connected each other, you can combine them into one quadrangle.
[Catmull-Clark] can make patches from both triangles and quadrangles. It becomes quite rounded compared to the former 2 types. It displays a little slower than other types, and wait is neglected.
When you want to convert patches to polygons, select menu - Object - Freeze. Patches are mostly frozen automatically
when you save a file except MQO format.