To keep the same Holant value, each the new vertices is assigned the binary equality constraint.
Vertex shaders can manipulate properties such as position, color and texture coordinate, but cannot create new vertices.
Add a new vertex to the graph, together with edges connecting it to two previously existing vertices.
In particular there is no action at the new vertices created.
The subdivide tool splits faces and edges into smaller pieces by adding new vertices.
Each triangle is divided into four subtriangles, adding new vertices in the middle of each edge.
All edges are shortened, and two new vertices are added on each original edge.
Introducing sources unifies the formalism, by making new vertices where one line can end.
New edges are formed between these new vertices.
Each group of 12 new vertices forms a cuboctahedron.