Thanks. This is welding the mesh. I meant searching for an alternative set of triangles for the same shape. Like when you have a cylinder cap. In 3dsMax for example the cap will be made of as many tris as there are segments in the cylinder. Then when you choose the "Optimize" modifier, the cap will be made of less triangles, where their axis point is no longer the center of the cylinder, but one of the segment edges. Ehrm, hard to explain for me. Imagine the unoptimized cap is looking like a 2D sun with lots of rays. The optimized cap looks more like a quarter of such a sun, where all rays start in one corner and go across the entire cap to every segment edge.