2 - Defining topology lines on reference images

2 - Defining topology lines on reference images
Eric Maslowski


Topology is the flow of surfaces over an environment or object.
We want to break the face in to key areas. What is meant by key areas?
If you look at an anatomy drawing, you can see how the muscles flow round key features, so our edge loops should have a similar flow to those muscles.

If you looking at a simple shape, such as a plane with a line bisecting it, if you drag the vertices up the shape will crease. If you move that bisecting line you get a different surface. This shows how edges play a role. We want and edge wherever we want a crease or protrusion in the surface that we need to control.

On your image, add edges at the wrinkles. Create a new layer, chose a bright colour, brush size 3, start drawing in certain areas, just to define the basic areas where there is a large crease or wrinkle or protrusion.
Just go through and try to isolate all the key areas.

Around eyes, eyebrows, crow’s feet bridge of nose, tip of nose, cheek bone. The cheek bone needs a lot of control as it gives definition to the face. Also make sure that you draw in the indentation under cheek bone and nasal folds. Think about how these join up. And draw in the topology. This is a good planning stage until we start modelling the character.

Now choose a new colour zoom in and have a smaller brush size and start tracing lines and placing quads. This gives flexibility, subdivision algorithms depend on quads and when you subdivide you get no pinching effects – if there is a triangle you will get pinching which is difficult to get rid off.

First stage is definition of eye and nose and side of nostrils. Place a small set of quads in between the nasal folds which gives flexibility later on when modelling for expression.

Add the cheek, and nose. You may get a direction changing quad, which can continue down the cheek or round the eye so topology can flow in any direction needed.

Chin area and side of mouth. Smile line on mouth is important so dimples can be added or puffy cheeks.

Forehead and upper lip edge flow from the cheek bone, try to approach the upper lip vertically. All muscles coming out of the lip are coming up vertically.
Nose – it can be difficult to see how this area can be broken into quads, try to avoid triangles. Think how surface should flow.

Sit back and think about your approach. If you create another layer and play around with your quad building you will become more aware of the process.

Now plot guidelines on the side image. Put on layers that you can toggle these on and off.