3D Topology: The Mesh

topology in 3d animations loganholme

What makes a clean mesh

Topology is an important aspect of 3D modeling and in most cases, it is the most vital. The word topology describes the layout of a model; how the vertices and edges are placed to create the mesh surface. It is important that we know how to create good topology in order to be excellent 3D modelers. Producing clean topology not only makes a 3D modeler’s life easier but also helps the production line to move much more efficiently. Good topology takes a lot of practice but there are a few aspects that are important to consider when creating a model.

Isolated Vertices
These are vertices that are not connected to any other point. This adds extra information that is not needed by the mesh and can cause problems later in the workflow. Why do you need it if it isn’t connected to anything anyway?

N-gons
N-gons are polygons with more than four sides. Generally when modelling for a game engine, most engines work with quads or triangles and n-gons make a mess of the equation. When an object is imported into a game engine or exported from the 3D program you are using, it calculates how many triangles are in the model for rendering. The more sides a polygon has, the more triangle calculations are needed which ends up with more render time.

Overlapping Vertices
Overlapping vertices are two points in the mesh that are in the exact same spot. This makes them look like one vertex to the eye of the viewer. Overlapping vertices should never be found in a model as there is no reason for two vertices to be in the one exact spot. This adds unnecessary information to the mesh and can even cause problems later in the workflow and in rendering. Why have two vertices in the exact same spot when you can have one?

Edge Flow
Edge flow is the way the loops of the edges run around the mesh. This usually mirrors real-world anatomy. An edge loop should be a continuous ring that follow a specific path around the model. These should be spaced out as evenly and practically possible, avoiding elongated faces. The better the flow of your edges, the easier it is for your organic model to deform when you animate it.

Thus creating good and clean topology using these considerations separate a good 3D artist from the great. Topology itself takes repetitive practice and patience in order to master but with the correct direction, the average 3D modeller is able to develop their abilities and skills into a more professional level.

EXTRA TERMS USED
Mesh – A set of vertices, edges, and faces that define the shape of a three dimensional object.
Rendering – In 3D computer graphics, this is the process of automatically converting 3D wireframs into 2D images with 3D photorealistic effects on the computer.

REFERENCES
Slick, J. (2014). 5 Common Pitfalls Of Beginning Modelers. About.com. [ONLINE] Available at: http://3d.about.com/od/Career-Resources/tp/5-Common-Pitfalls-Of-Beginning-Modelers.htm. [Accessed 04 December 2014].

Tips and tricks for organic modelling (2014). Creative Bloq. [ONLINE] Available at:http://www.creativebloq.com/tips-and-tricks-organic-modelling-7123070. [Accessed 04 December 2014].