3ds Max 2012 Bible - Kelly L. Murdock [71]
FIGURE 5.10
Sphere primitives of various Segment values with the Smooth option turned on and off
Figure 5.11 shows two hemispheres with Hemisphere values of 0.5. The Edged Faces option was enabled so you can see the polygon faces. The left hemisphere was created using the Chop option, and the right hemisphere was created with the Squash option. Notice how many extra polygons are included in the right hemisphere.
FIGURE 5.11
Creating hemispheres with the Chop and Squash options
The Slice option enables you to dissect the sphere into slices (like segmenting an orange). The Slice From and Slice To fields accept values ranging from 0 to 360 degrees. Figure 5.12 shows four spheres that have been sliced. Notice that because the Segments value hasn't changed, all slices have the same number of faces.
Note
You can use the Slice feature on several primitives, including the sphere, cylinder, torus, cone, tube, oiltank, spindle, chamfercyl, and capsule. •
FIGURE 5.12
Using the Slice option to create sphere slices
The Base to Pivot parameter determines whether the position of the pivot point (or the point about which the object rotates) is at the bottom of the sphere or at the center. The default (with the Base to Pivot setting not enabled) sets the pivot point for the sphere at the center of the sphere.
Cylinder
You can use a cylinder in many places—for example, as a pillar in front of a home or as a car driveshaft. To create one, first specify a base circle and then a height. The default number of sides is 18, which produces a smooth cylinder. Height and Cap Segments values define the number of polygons that make up the cylinder sides and caps. The Smooth and Slice options work the same as they do with a sphere (see the preceding section).
Tip
If you don't plan on modifying the ends of the cylinder, make the Cap Segments equal to 1 to keep the model complexity down. •
Torus
A torus (which is the mathematical name for a “doughnut”) is a ring with a circular cross section. To create a torus, you need to specify two radii values. The first is the value from the center of the torus to the center of the ring; the second is the radius of the circular cross section. The default settings create a torus with 24 segments and 12 sides. The Rotation and Twist options cause the sides to twist a specified value as the ring is circumnavigated.
Figure 5.13 shows some sample toruses with a Smooth setting of None. The first three have Segments values of 24, 12, and 6. The last two have Twist values of 90 and 360. The higher the number of segments, the rounder the torus looks when viewed from above. The default of 24 is sufficient to create a smooth torus. The number of sides defines the circular smoothness of the cross section.
FIGURE 5.13
Using the Segments and Twist options on a torus
The Parameters rollout includes settings for four different Smooth options. The All option smoothes all edges, and the None option displays all polygons as faceted. The Sides option smoothes edges between sides, resulting in a torus with banded sides. The Segment option smoothes between segment edges, resulting in separate smooth sections around the torus.
The Slice options work with a torus the same way as they do with the sphere and cylinder objects; see the “Sphere” section earlier in this chapter.
Teapot
Okay, let's all sing together, “I'm a little teapot, short and stout. . . .” The teapot is another object that, like the sphere, is easy to create. Within the Parameters rollout, you can specify the number of Segments, whether the surface is smooth or faceted, and which parts to display, including Body, Handle, Spout, and Lid.
Note
You may recognize most of these primitives as standard shapes, with the exception of the teapot. The teapot has a special place in computer graphics. In early computer graphics development labs, the teapot was chosen as the test model for many early algorithms. It is still included as a valuable benchmark for computer graphics programmers. •
Cone
The Cone object,