Topology refers to the layout of the model and shows the flow and polygons of the character. In our case only using quads. Topology determines the number of polygons that the model contains. and shows ‘Edge Flow’ This is a clear view of the flow of the model.A good example of this is with a character model. The edge flow through the pectorals can be seen going up and around the back of the head.
Edge flow can be identified by drawing a quad shape and having an arrow pointing to it. The side the arrow then comes out is the edge flow. The reason that we are using quads and not triangles are because the edge flow is harder to follow on triangles as when the arrow enters the triangle it is hard to determine which side it should come out as there is no way to show this.
Bad topology is where the polygons have been stretched and the flow can not be seen.It also disrupts the shape of the model. Another example of bad topology is where an excessive amount of polygons have been used where they did need to be. However, this can also be an essential thing on models such as characters as the elbow need more polygons so that they can bend.