Best practice for facial topology

Facial Topology is the study of the face, focusing on volume, shape and proportions of the features while understanding where and how they are positioned on the face. Proportions are height, width, depth, size of one area with the size of another and the space between two areas or features.
Here are some common words used within facial topology and their meanings.
The mesh is a wire like framework that surrounds a 3D model. It is a grid of lines made up of different shapes (usually squares) that is used to determine the location of polygons when increasing or decreasing the polygon count. It also shows how the face would be animated by the direction or flow of the lines on the mesh. When the polygon count increases, a square would divide into four equal sized squares. The higher the number of lines on a mesh, the smoother the model can be, however it also takes up more memory and could slow down the computer, this is directly affected by the number of lines, the size of the model and the computing power.
A quad is where four lines on a mesh meet. It is now the most common shape on mesh as it is the easiest shape to divide when increasing the resolution or subdividing the mesh.
A tri is where three points on a mesh meet. It is usually used when the mesh flow changes direction.
Poles are where three or more mesh lines meet at a point. Poles act like anchor points which controls the flow of the mesh (direction of the mesh lines). Poles are best placed on the face where there will be the least amount of animation. There are usually around ten poles in a face model positioned in the edge loops. There is no right or wrong place to put poles, it depends on what parts of the face will be animated and what shape the face will be. Every head, whether it be characteristic, realistic, alien or monster, all heads look different, for this reason there is no universal right or wrong place to put poles.
Loops or Edge loops are loops of mesh that go around the features of the face you want to animate. They are usually highlighted in mesh pictures with different colours, this is purely to highlight their location and it has no other relevance to animation. It is important to have edge loops around features as it enables a more natural animation movement. Some edge loops mimic the facial muscles around features like the mouth and eyes; they both have circular muscle to control the movement. The edge loops are a simplification of the complex muscle network within the face, the more accurate position of edge loops to real muscle structure, the more realistic the animation.
Important things to remember and different ways to model in 3D.
There are different methods to use when modelling a 3D head; some professionals prefer a new mesh design for every face, with specific edge loops and poles created specifically for one face, others prefer to use a generic head mesh with edge loops and pools already included, which can be manipulated to fit the face. There are benefits and drawbacks to both, and neither is right or wrong, it depends on how the modeller prefers to work and what they find the most suitable for a given task.
When creating a new mesh to work from, one way to achieve this is to work from two photos or drawings of a face, one in profile, and one straight on. It is then possible to draw on the straight on photo/drawing, the edge loops in 2D. The 3D mesh is created by dragging the mesh lines out along the profile picture/drawing to get the depth of the 3D mesh.
An important thing to remember and keep in mind while doing a 3D head model is that the head is organic. The human head is a complicated combination of muscle, skin of different colours and textures, nerves, bone and hair of different thicknesses and direction. Modelling is in essence, a simplification of these complicated systems (you only have to model what’s on the outside), but understanding how the muscles, tendons and ligaments work on the inside makes modelling easier to do. It’s like you have been given a task to draw a cityscape with lots of buildings, but you own most of the buildings in the city so you have prior knowledge of where the buildings are in relation to each other.
Certain parts of the face act as reference point for others on the face, and they are somewhat universal for all heads, however, every head is different so the relation between features is only a rough guide.
The eyes are positioned roughly half way down the face; the eye length should be the same distance between the eyes, and between the eye and the side of the head. (The eye lid is usually thinker than is first thought, a thick eyelid looks more realistic than a think eyelid.)
The top of the ears, should line up with the eyes, and the bottom of the ear (lobe) should line up somewhere between the bottom of the nose and the top of the mouth.
The corners of the mouth act as reference point for several parts of the face. They line up with the centre of the eyes and create a reference point for the cheeks and nostrils.
The human brain is very adapted in recognising patterns and symmetry, the same applies for the face, if the face is made identical on both sides, it is inaccurate as no head is symmetrical. For a very accurate 3D head, the modeller has to change the shape and size of some features, eyes are not always the same size or the nose may be bent to one side.
Conclusion
There is no best practice for facial topology across any software platform, there is only best practices for the specific job you are doing, what may be a good technique in one face may be a different in another type of face. With technology advancing and the software used to create models via a computer are becoming more advanced, the techniques used to do so will no doubt change and adapt with it. The one thing that will stay the same is that all heads look different but they are share similar proportions.

Thoughts while researching facial topology best practice

To begin with, researching facial topology seemed daunting, it didn’t seem like there was much information on the internet. If you type facial topology into Google, you don’t get much, the next point of call Wikipedia wasn’t much help either, only explaining the mathematical meaning of the word topology. It was on the right track as it explained about spatial properties, but it wasn’t in the context of modelling. Modelling is very mathematical in its process, and spatial awareness was important. Wikipedia only gave geometry information, there is a fine line between geometry and modelling, but there was nothing on the website that was relevant about art. A lot of information of that page went over my head.
While researching facial topology the blogs I came across seemed geared towards helping other people learn rather that portraying an excuse to show off an artistic ability at a specific medium. This was a new experience and one quite far removed from researching something on fine art or Photoshop art. This could be due the inherent lack of knowledge in most people about 3D modelling; it appears the medium has drawn to it a small group of artists that enjoy teaching and sharing the skills needed rather than using it as a platform for recognition. There seemed to be a great comradely between different model artists on the blogs, there was sharing of knowledge and skill. I feel that this is due several reasons; it’s a new art form and so not many people know how to do it, although it is directly related to physical modelling it is difficult to do, it is not as intuitive as painting or drawing or even physical modelling. This is because thought always has to be given to what tool is used, how strong and what size it is.
While searching through a few different blogs I even stumbled across a fellow student in my class, asking for help on a blog, several bloggers were attentive, giving information happily.
After learning about 3D modelling it became easier to search for relative information as it was possible to search for key words used within the industry, like “Sub-divide”, “Edge Loops” and “Poles”. The Student resources folder on the University computer network was also helpful in its content.

Thoughts on 3D Mudbox tutorial

Making the 3D maquette out of polymer clay aloud for the techniques and process of real world model making to be leant. This way the fundamental principles could be applied when using the Mudbox software.
It was easy to learn how tools worked on a piece of digital clay with a prior knowledge about how the clay would be affected by which tools.
Some tools like the knife or pinch tool acted as they would in reality, other tools cannot exist in reality like the bulge tool.
The most obvious difference between modelling in reality and 3d modelling with software is the wire mesh. Which is important if animation is a factor and when reducing the polygon count.
If the model is thought of in Lego bricks, and the mesh determines where each brick goes, it’s best to have as many parallel lines and straight edges for the bricks to be placed in, so if the model were made out of large Lego bricks it would still look realistic.
The hardest part to learn about the Mudbox software was the strength and size of the tools and knowing how they would affect the model. It is like most crafts, easy to learn but difficult to master. With a physical piece of clay, it is easy to know what will happen when fingers or a tool is used with varying amounts of force and pressure, but with no prior knowledge of Mudbox, there was no way to determine what affect a stylus stroke would have on the model. Luckily for software there is always the undo button, sadly the same cannot be said for real model making.

Story of making maquette over 2 days

1.1. I started off by covering the polystyrene egg in tin foil so if there was any polystyrene left exposed, it wouldn’t burn in the oven.

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2. The next stage was to cover the egg in a layer of clay

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3. After that, I mapped out where the features of the face would be in a raised edge of clay. I also mapped out how tall and wide the edge shape would be.

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4. After building up some layers of the head, the position of the chin was changed, and the position of the lips was added.

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5. Here the shape of the head looks more accurate and the ridge of the eye sockets has been added,

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6. At this stage the cheeks have been more flushed out and the eye ridge has been worked into the rest of the head. This is where the maquette looks most like a skull. I wanted to experiment using the clay like it were muscle to see if was an effective way to create a head, I found it was very difficult and gave up this experiment fairly quickly.

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7. Here the nose has been more filled out and the position of the lips has been indicated with a ridge of clay.

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8. Then the cheeks, head and chin were smoothed out, and detail was added to the nose and lips.

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9. The next picture depicts further smoothing out and detail added, each time trying to make the maquette resemble Oliver

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The last stage was to add some hair detail to the eyebrows and top lip with a wire tool. I decided not to give the maquette head hair as I wanted to focus my time on making the face look as accurate as possible.