
	Eg 3: Surfacing a Torso

Figure 344. The Torso Mesh

In this example you will see how a human torso is surfaced using the new spline projection tool in combination with Maya. The approach taken is to make three surfaces, one for each arm and one for the chest, and then use Maya's fillet blend tool to join them together at the shoulders.

The Arms

Figure 345. Slicing Up the Arm

First draw a projection spline up one of the arms, turn it into a Spine, adjust the first and last rib widths, and finish off by cutting the slices (see Figure 345).

Figure 346. Topmost Slice

Now focus in on the shoulder area. Start by drawing a projection spline that will be the upper limit of the arm surface (see Figure 346). Cut that slice, and continue editing the projection spline and cutting slices to fill in the shoulder area (see Figure 347). The shortcut keys <q> and <w> come in very handy here.

Figure 347. Remaining Arm Slices

The important thing is to get a nice even spacing between slices. If you look carefully, you can see that the topmost of the initial rib slices has been bent around slightly. In fact, to ensure that the slices "flowed" in a nice way, it was deleted and replaced with a curved projection spline. If there are sharp changes in slice spacing, then you will get unwanted folding in the final lofted surface.

Figure 348. Drawing Split Line

Project a split line onto the inside of the arm (see Figure 348). In most situations similar to this you could disable cutting through the Back faces. This is so you only get a slice line up the inside of the arm (ie the surface facing you, the ones shaded white), and not another one up the outside that you don't need. But because the armpit surface curves around sharply, you'll need to cut both Front and Back faces, and remember to remove the unwanted slice up the outside of the arm.

Figure 349. Checking Slice Directions

Use the slice you just projected to Split the arms sectional slices; this makes sure that their start and end points are aligned. Now Hide the mesh and look carefully at the slice arrows (see Figure 349). You can make the arrows large by typing <a>, and hit <a> a couple more times to turn them back to their normal size. All the slices created from the projected ribs will have the same direction, but the ones you drew yourself may or may not. Pick all incorrect slices and Reverse their direction before continuing.

You are now ready to create the arm surface. Determine how many control points you want around each of the slices, say about 15 in this example, and enter that number into the Points field in the main CySlice window. Now pick all the arm slices and click on the Spline button; each slice will be interpolated with a 15 control point NURBS curve.

Figure 350. The Arm Surface

At this point, if you are running CySlice as a Maya plugin, click on the Transfer to Maya button and the splines will be loaded into the Maya modeler. Select the slices in order and loft them to create the surface (see Figure 350).

If you aren't running CySlice as a Maya or PowerAnimator plugin, you can still save the splines out to an IGES file, then load that file into your own modeler to create the surface.

Once you are happy with the arm surface, either Delete the arm slices, or push them onto the Temp layer so they don't clutter up the display.

Now create the second arm in exactly the same way you just created the first.