3D Topology

3D topology is the geometry of a 3D model and the overall structure of the vertices, edges and faces of a 3D model. The models can be made up of 3 types of topology, which are Tris (3-sided), Quads (4-sided) and N’gons (5+ sided).

The topology can collate from four or more points. Four points that join together are called “Vertices”. Not to be confused by five or more points that join together, referred to as a “pole”.

Tris Topology

Pros:

• Useful for simplistic models
• The file size is smaller

Cons:

• Can’t create complex models
• Textures are a lot smaller and less detailed

Quad Topology

Pros:

• More sophisticated and detailed model
• Can be imported to different programs without complications, errors or glitches.

Cons:

• Might cause texturing to not line up correctly
• Is more time consuming to create

N’gone Topology

Pros:

• Requires fewer patches and components to create a complex model
• Quicker to model with

Cons:

• Leads to odd rendering that are hard or impossible to eliminate
• Hard to convert to different programs, making the model not as smooth

Polygonal modelling can really be used for making any objects but usually used for more smooth and refined objected like a sphere. It can also be used for more complicated models.

Good Topology

This model has been organised with quads that flow similarly to the way muscles work in order for the model to make anatomically correct bends and flex. This model also will have better texturing and rendering because of the organisation of the quads.

Bad Topology

6. Find an example of bad topology and explain why it is bad

This model has also been organised with quads. However, the vertexes and vertices of some quads don’t match a similar square shape to the rest of the quads, like the ones behind the ear of the model don’t match with the ones on the front of the head. Another problem is the spot marked in red, the vertexes are connected by three instead of four as a quad topology. This will make the texture look funny as the texturing is designed for four vertexes, not three.

You can get away with bad topology however when using flatter surfaced models and also to save time on creating models. Like using Tris topology instead of quad topology to save time but also same the same quality.

Polygonal modelling can really be used for making any objects but usually used for more smooth and refined objected like a sphere. It can also be used for more complicated models.

NURB stands for Non-uniform rational B-spline. This type of modelling also you to use less point on more refined models, again like a sphere. This makes the model minimal by using four sides at most.

Sub-Divisional is also known as “NURMS”, is quite similar to polygonal topology but it automatically smoothes the model. This modelling is much faster than polygonal topology while retaining the same quality as topology.

Two-Manifold topology:

Polygons with Two-Manifold topology ate shapes that can be split along its own edges and folded out so that it looks like a net for a 3D shape like a cube or even a a sphere.

Non-Manifold topology:

Polygons with non-manifold topology use an arrangement that makes it so that it can’t be pulled into a net-like form and some tools in Maya won’t work with these shapes because od the non-manifold topology.