Working with Vertices, Edges, and Faces

Every single 3D model is made out of the same three elements: vertices, edges, and faces. A vertex is a point in space. When you connect two vertices, you’ve created an edge and if you connect three or more vertices in a closed loop, then you’ve created a face. A face is basically a polygon. You can see these elements in Figure 6.1.

Figure 6.1 Vertices, edges, and faces—the elements that make up every 3D mesh

There are three types of faces: triangles, quads (four-sided faces), and n-gons (faces with more than four sides). In 3D, there is a “rule” that, if you can, you should use four-sided faces everywhere. The reason is that they deform better in animation, and if you’re going to use a Subdivision Surface modifier on the mesh, four-sided faces usually subdivide correctly. Triangles and n-gons can be problematic at times by creating “pinches” in the mesh.

There are some situations, though, in which using a triangle or an n-gon is more beneficial for the mesh; for example, in some complex formations, n-gons create better deformations and subdivisions than four-sided polygons. Experience in modeling is needed to discern those situations and there are a lot of articles by very experienced modelers on this subject that you’re encouraged to look into, as it’s not covered in the scope of this book.