Six basic schemes of the topology simplifying:
1-2. Two polygons to one (2/1)
Two polygons in the input become the one polygon in the output.
The connection is two quad polygons between.
In the first scheme, the polygons directed from the top and the left side. At the second one from the top and right side.
It used when you need to simplify the crossed loops.
3. Three polygons to one (3/1)
Three polygons in the input become the one polygon in the output. The connection is the one quad polygon between.
4. Three polygons to two (3/2)
Three polygons in the input become two polygons in the output. The connection is four polygons.
5. Four polygons to two (4/2)
Four polygons in the input become two polygons in the output. The connection is two quad polygons.
6. Five polygons to three (5/3)
Five polygons in the input become three polygons in the output. The connection is six quad polygons.
