Hair, Face, and Neck Optimization
The geometry that makes up Kila's head and hair is a goldmine of opportunities where we can remove lots of polygons. Let's begin with the hair.
Hide everything apart from her hair and face. Template the face (using the method explained earlier for working with the jeans), so we can work on just the top part of her hair.
To start, there are quite a few areas where we can collapse edges because there are so many shallow angles.
Select the edges shown in Figure 5.27, selecting them all around her hair, and collapse them.
Figure 5.27. Select and collapse every other edge, to reduce the hair.
Leave the very bottom of the hair intact, however. This area is divided into separate strips, so collapsing the edges constructing the strips will remove them. Kila's hair should now look like that in Figure 5.28.
Figure 5.28. The hair after the edges are collapsed.
Take another look; there are still a couple of shallow angles that can be removed without affecting the overall shape of her hair.
As shown in Figure 5.29, select the middle row of edges and collapse them, leaving the hair as seen in Figure 5.30.
Figure 5.29. Reduce the hair further by removing this row of edges.
Figure 5.30. The hair after removing the middle row of edges.
Moving around now to the front of her hair, we can have a look and see if we can get away with removing a polygon or two from here. Try selecting and collapsing the edges shown in Figure 5.31 (left); does it still look okay?
Figure 5.31. Try removing a few edges from the front.
Although it does looks fine (Figure 5.31, right), altering the hairline like this will reduce the number of vertices along that edge, thereby changing how the face mesh lines up with the hair. This will become obvious when the face is untemplated in subsequent steps.
Continue looking around the geometry for polygons to be removed. Another one lies right on the top; you can see it in Figure 5.32 (left). It's a small polygon and so should not cause any major problems when it's removed.
Figure 5.32. Remove this tiny polygon from the top of her hair.
We are finished now with the top portion of the hair; let's optimize the inner layers next.
Isolate the first layer so we can work on it alone (Figure 5.33, top).
Figure 5.33. Collapse the top strip of edges on the first layer of hair.
As shown in the middle image of Figure 5.33, select every other edge around the very top and collapse them. We can do this because the top layer of hair will hide most of these polygons. We still need them to exist, though, so that you don't see through her head.
Since this is an inner layer, the curves in the geometry need not be perfectly smooth. That means we can reduce this layer some more by removing an entire row of polygons. This is shown in Figure 5.34.
Figure 5.34. Further reduce the inner layer by removing a row of polygons from the strips.
Now follow the same procedure for the other inner layers of hair. When you're done, the geometry will look like that in Figure 5.35.
Figure 5.35. More reductions on the other inner layers
The Face and Neck
The hair's done; now let's work on her face. One quick look will show many areas where you can reduce the mesh.
Start with the forehead. I chose to begin here because we've already reduced her hairline, and the vertices in her hair no longer line up with her head.
Follow the edges down the brow, starting with the same edges we removed from her hair, until you get to the eye area. If you're not sure which edges to choose, they're shown in Figure 5.36 (left). Judging by the results in Figure 5.36 (right), removing these edges doesn't cause a problem.
Figure 5.36. Optimizing the forehead
Time to make our first sacrifice; we need to reduce her ear. This is not a major loss, however, because the texture will hold all the detail we need.
Flatten the outer face of the ear, but try to retain the ear's general shape (Figure 5.37).
Figure 5.37. Flatten out the face of the ear, keeping the overall shape.
It looks like we can reduce the ear a little more by collapsing the edges highlighted in Figure 5.38 (left). This will ultimately affect the ear's overall shape, but not too much.
Figure 5.38. Collapse these three edges.
Looking around, you'll spot a small polygon nearly out of sight on the inside (Figure 5.39, left); remove this. Then go ahead and work a little more on the ear's general shape, and see if you can remove any more polygons.
Figure 5.39. Collapse this small polygon hiding on the inside of the ear.
After the ear is done, the next major area to examine is under her chin. You can see in Figure 5.40 (left) that there are lots of unused polygons here.
We can probably get away with flattening the area as demonstrated in Figure 5.40 (right), although I admit I'm not entirely comfortable with removing this many polygons in one go because it does affect the shape. After we're finished, if we're under our budget, we can always add a bit back into this area to fill out the shape.
Removing so much from the chin will make other potential trim areas stand out. The edges in Figure 5.41 (left), for example, lead up from a now-unused edge around her jaw.
Figure 5.41. Working up from the jaw line, remove polygons from her cheek.
Again, optimizing the underside of her chin has made other reduction possibilities leap right out at us. Look at the chin itself: We definitely don't need all six of those subdivisions. Removing the bottom edge alone, however, may cause some odd-looking results. So work your way up as I have done in Figure 5.42 (left), optimizing the lips, too.
Figure 5.42. Reduce the subdivisions in her chin and lips.
Removing the edges from the lips has left us with two stray vertices, shown in Figure 5.43 at the top. Weld these vertices to the ones closest to them, smoothing out the upper lip (Figure 5.43, bottom).
Figure 5.43. Smoothing out the upper lip
Figure 5.40. Flatten the area under her chin.
Next, we will examine Kila's eyes before moving on to the rest of her head. They are quite round, but we don't actually need this amount of detail.
We can get away with collapsing the edges highlighted in Figure 5.44 (left), before moving the remaining vertices to reshape the eye as shown in Figure 5.44 (right). By doing this, we'll regain 18 quads, or 36 polygons.
Figure 5.44. Reducing and reshaping the eyes
Now look at the bridge of the nose from the side. You'll spot an area that is quite flat. There are three vertical subdivisions making up this area, but we can live with just two.
Select the edges that make up the central division of the nose. Optimizing the bridge of the nose means we can also reduce her cheeks, so work your way around them and see what you can do (Figure 5.45).
Figure 5.45. Optimizing the bridge of her nose and the cheeks
Here's something less obvious: Notice the small polygon next to the corner of her eye, shown in Figure 5.46. Select and collapse this, as it is not needed.
Figure 5.46. Here's an edge you can collapse without taking away from the shape of the eye.
It's important to keep your eyes peeled, looking for potential areas of optimization that are less easily seen, like this one.
When you are unsure about removing a particular polygon, go ahead and try itif the geometry looks wrong, you can always press Z/Cmd+Z to undo the operation. And Shift+Z/Shift+Cmd+Z will redo the last undo.
The back of Kila's head would be another good place to look for optimization opportunities, because her hair will cover it. In Figure 5.47 (left), you can see an edge that might potentially be collapsed.
Figure 5.47. This area at the back of the head can be reduced.
Now move around the head, scanning the surface for anything you might remove. Above the nostril we built in the crease, but this is such a small polygon we just can't justify keeping it, so collapse this edge (Figure 5.48).
Figure 5.48. The small polygon above her nostril can be removed.
Returning to the back of her neck, it looks like we can do some additional reduction. Shown in the top image of Figure 5.49, there are two quads on the sides of the neck that do not offer much in the way of shape or deformation. These edges can be removed, but make sure to fine-tune the new geometry so that the form correctly resembles the back of a neck.
Figure 5.49. You can reduce these edges, but you'll need to reshape the area afterward.
Taking one last look around the head, we notice an edge under the jaw that we can remove (Figure 5.50). This cleans up the area nicely.
Figure 5.50. On final inspection: an extra edge under the jaw and a muscle in the neck.
Another spot we can remove in this area is the muscle definition in the side of the neck, also shown in Figure 5.50. Ultimately this does not add to the character; besides, the muscle tone here can be drawn into the texture if we need it.
The face is now complete and can be seen in Figure 5.51. As mentioned earlier, we may have removed too much from a few areas, but we will wait and see how things shape up. If we come in well below our limit, we can go back in and rework some areas.
Figure 5.51. The fully optimized face
Now bring back the rest of the geometry so it is visible. Because we removed the detail from the upper part of the neck, we must now remove it from the lower portion as well, so they match up (Figure 5.52).
Figure 5.52. Optimize the lower neck so that it matches the upper portion that we trimmed.