Each edge has two vertices-the start and end points of the edge. When more than one edge is created, shared vertices are recorded. This enables the function to determine how many fillets meet at a vertex. Using a primitive cube as an example, each vertex is shared by three edges. If only one profile is defined along an edge, or more than one profile is defined but they all share the same radius value, then a circular fillet is created.
Circular fillets are fillets that have a constant radius.
Variable fillet A variable fillet is created when there are two or more profiles defined along an edge that have different radius values. The fillet size along a variable edge is the result of smoothly interpolating the profile values. A blending surface is the result of Round attempting to create surfaces to blend the fillets that join at a vertex. The blending surface created may be either a trimmed surface or a four-sided patch. Toggle this option OFF since non-rational geometry is preferred.