Figure 1
The splines that trace the front and rear profiles of this head must lie "flat" on the ZY plane, with X values of 0m. Otherwise, the points along the seam will not line up when the patches of this cage are Mirrored across the X axis.
We have to make certain that no unwanted "dips" happen along the center seam of this model.
While we're at it, we might as well Smooth some of the adjacent curves together, so that they look as rounded as a single curve. A minor concern for a cage that will be patched with 2-by-2 patches, but important if this cage will be used in the future to generate higher-resolution models.
Last but not least, we need to make sure that no "hidden" splines lurk in this spline cage.
STEP 1: Load head03.lwo into Modeler. (If you did not follow the steps in the previous section and just want experience in refining a spline cage, you may load head03.lwo from the CD-ROM).
STEP 2: Select all the splines that run along the center of the head in the Back View. Type Ctrl-v to bring up Set Value, and choose a value of 0m on the X axis. Chief concern number one has just been addressed. Leave these central splines selected. (Figure 1)
Figure 1
STEP 3: We're going to Mirror the splines of the face, and we don't need duplicates of the central splines. With the central splines selected, type the double-quotes key to Invert your selection. Now everything but the central splines should be selected. The neck circle is already "mirrored," so deselect the four splines of the neck circle.
STEP 4: Mirror the selected splines across 0m on the X
axis, with Merge Points turned on. It should look like Figure
2.
Figure 2 |
Figure 3 |
STEP 5: Select the five pairs of splines shown in Figure 3 (the pairs that define the sides of the head, the forehead, the brow, and the bridge of the nose) and type Ctrl-s to Smooth them.
STEP 6: Select the four pairs of splines shown in Figure
4 (the diagonal splines of the brow, the cheek splines that
meet at the tip of the nose, the pair of splines that form the chin, and
the pair of splines that form the top of the upper lip) and type Ctrl-s
to Smooth them.
Figure 4 |
Figure 5 |
STEP 7: Select the two pairs of splines shown in Figure 5 (the pairs that define the underside of the nose and the bottom of the lower lip region) and type Ctrl-s to Smooth them.
STEP 8: Select the two pairs of splines shown in Figure
6 (the pairs that define the underside of the upper lip
and the "muzzle" of the mouth) and type Ctrl-s to Smooth them.
Figure 6 |
Figure 7 |
STEP 9: Select the pair of splines defining the top of the lower lip, and type Ctrl-s to Smooth them.
STEP 10: One more pair of splines. Select the pair of splines shown in Figure 7 and type Ctrl-s to Smooth them.
Note: If you had tried to Smooth all of these splines at once, you might have accidentally Smoothed them in unwanted areas. For example, if you had selected all of the splines defining the mouth and Smoothed them at the same time, you would have Smoothed the corners of the mouth as well.
Smoothing those contours that cross the center of the spline cage will help you get a more accurate idea of how the center seam would (should) look in the resulting SubPatch model. Smoothing a spline also lets you achieve flatter curves near the end of the spline than would be possible otherwise.
STEP 11: We've gained our control points; we don't need the other
half of the face anymore. Select those splines on the left side of the
face in the Back View (the elf-girl's "right side") and type x to Cut them
out. It should look like Figure
8. Those "floating" points are our control points, belonging
to the splines we Smoothed in Steps 5 through 10.
Figure 8 |
Figure 9 |
STEP 12: While we're Smoothing curves, Smooth the two pairs of curves that orbit the eye in Figure 9.
STEP 13: Activate Symmetry Mode (Modes > Symmetry On/Off).
STEP 14: Edit the contours of this cage as you see fit with the Drag tool. With Symmetry Mode turned on, the splines we Smoothed in Steps 5 through 10 will stay "Smoothed" as we drag their points around. This is because their control points on the negative side of the X axis were formed from Mirrored points from the positive side of the X axis.
Your chief concern is making sure that the splines you just Smoothed form half-arches where they meet at the center of the head in the Back View. If they form half-heart shapes, then you will see a "dip" in the contour at the center seam when this spline cage is Patched and the patches are Mirrored. See Figure 10 for an exaggerated example of an unwanted half-heart shape. (The panel on the left shows the unwanted "dip" in the spline; the panel on the right shows the correctly shaped spline).
Figure 10
Also check to see that the splines form graceful curves. The more rounded the form, the better the celshading.
STEP 15: When you have finished editing, deselect everything. Type m to Merge Points (just in case), then type Shift-i to Unify any "hidden splines" (just in case).
STEP 16: Save this object as head04.lwo.