Topology

Having finished the sculpt I then needed to finish my final piece of work for the sculpting project, topology research. I decided my first task was to find a definition of topology. My first stop on my researching quest was the forums of cgsociety.org. Someone had already asked what the definition was in this (http://forums.cgsociety.org/archive/index.php/t-416197.html) thread. There were two replies which interested me. The first was a more literal definition using the greek words that combine to make the word "topology". "Topos" means "place" and "logos" means study (newellteapot, 2006). Topology literally means the study of places. The second definition was, "basically for organic mesh you will want all quad using edge loops to define muscle and bone of the mesh. Edge loops function as defining the lines/curves/creases of an organic mesh. Also, it is important that all polygons have a similar density and size in the mesh for an efficient and accurate subdivision and deformation" (MasonDoran, 2006).
The user goes on to say that the topology need not be so strict for non-organic meshes such as building, vehicles or mecha. Although attention should still be paid to the size, shape and placement of the polygons if the model is to be subdivided or distorted.
To sum up, topology is the study of places, in 3D modelling it is the study of the "placement" of polygons to ensure proper subdivision and distortion.

After finding the definition I then needed to look further into what facial topology should look like, and why. After a bit of research I found this website (http://www.phungdinhdung.org/Studies_paper/Realistic_face_modeling.shtm#3.2-%20Topology:) which explained that the topology not only needs to define the face, but also needs to be able to deform in the same way the face will when animated. This means that the topology can change from face to face depending on the personal preference of the artist, the shape of the face itself, the art style and the animations the face needs to do. After seeing some illustrations on this page where the artist had drawn over some photographs to find deformations in the face, I decided to do the same. Luckily, when photographing my model, we took a few mock photos where the model pulled a few faces, this was perfect for figuring out how his face deformed.

Using these pictures, and illustrations from Stop Staring; Facial Modelling and Animation Done Right by Jason Osipa plan out a very rough topology for the 3D sculpt.

Although this rough plan wasn't perfect, I saw this as enough to start work on the 3D sculpt itself.
I am fairly happy with how the topology of the sculpt turned out. However, knowing that triangles do not subdivide or animate well, I had to create a couple of 5poles (a vertex where 5 polygons meet) to avoid them. I ended up with three on each side. This is 2 more than would have been ideal, since having at least 1 5pole is virtually impossible when avoiding tri's. Another small problem I think I had, is that I sometimes had to split polygons to ensure that the quads (a four sided polygon) of one edge loop (an edge that loops back on itself; these are useful for connecting distant areas connected by muscle, such as the eyes and the area above the mouth) remained a similar size. I would much rather keep every edge connected by edge loops, but this would have left some polygons unbalanced in size.

Although I used a book for reference I did not copy. Even though this means I may suffer for it. I would rather attempt topology without copying, fail and learn from my mistakes, than copy the topology and learn nothing about working out topology myself.