3ds Max 2012 Bible - Kelly L. Murdock [72]
In addition to the two cap radii and the Height, parameter options include the number of Height and Cap Segments, the number of Sides, and the Smooth and Slice options.
GeoSphere
The GeoSphere object is a sphere created by using fewer polygon faces than the standard Sphere object. This type of sphere spreads the polygon faces, which are all roughly equal in size, around the object, instead of concentrating them on either end like the normal Sphere object. This makes the GeoSphere a better choice for surface modeling because its polygon resolution is consistent. Geospheres also render more quickly and have faster transformation times than normal spheres. One reason for this is that a GeoSphere uses triangle faces instead of square faces.
In the Parameters rollout are several Geodesic Base Type options, including Tetra, Octa, and Icosa. The Tetra type is based on a four-sided tetrahedron, the Octa type is based on an eight-sided Octahedron, and the Icosa type is based on the 20-sided Icosahedron. Setting the Segment value to 1 produces each of these Hedra shapes. Each type aligns the triangle faces differently.
GeoSpheres also have the same Smooth, Hemisphere, and Base to Pivot options as the Sphere primitive. Selecting the Hemisphere option changes the GeoSphere into a hemisphere, but you have no additional options like Chop and Squash. GeoSphere primitives do not include an option to be sliced.
Tutorial: Comparing Spheres and GeoSpheres
To prove that GeoSpheres are more efficient than Sphere objects, follow these steps:
1. Create a normal Sphere, and set its Segment value to 4.
2. Next to the Sphere object, create a GeoSphere object with a Tetra Base Type and the number of Segments set to 4.
3. Create another GeoSphere object with the Octa Base Type and 4 Segments.
4. Finally, create a GeoSphere with the Icosa Base Type and 4 Segments.
Figure 5.14 shows these spheres as a comparison. The normal sphere, shown to the left, looks like a diamond, but the GeoSpheres still resemble spheres. Notice that the Icosa type GeoSphere, shown on the right, produces the smoothest sphere.
FIGURE 5.14
Even with a similar number of segments, GeoSpheres are much more spherical.
Tube
The Tube primitive is useful any time you need a pipe object. You can also use it to create ring-shaped objects that have rectangular cross sections. Creating a Tube object is very similar to the Cylinder and Cone objects. Tube parameters include two radii for the inner and outer tube walls. Tubes also have the Smooth and Slice options.
Pyramid
Pyramid primitives are constructed with a rectangular base and triangles at each edge that rise to meet at the top, just like the ones in Egypt, only easier to build. Two different creation methods are used to create the base rectangle. With the Base/Apex method, you create the base by dragging corner to corner, and with the Center method, you drag from the base center to a corner.
The Width and Depth parameters define the base dimensions, and the Height value determines how tall the pyramid is. You can also specify the number of segments for each dimension.
Plane
The Plane object enables you to model the Great Plains (good pun, eh?). The Plane primitive creates a simple plane that looks like a rectangle, but it includes Multiplier parameters that let you specify the size of the plane at render time. This feature makes working in a viewport convenient because you don't have to worry about creating a huge plane object representing the ground plane that makes all other scene objects really small in comparison.
Tip
Dense plane objects can be made into a terrain by randomly altering the height of each interior vertex with a Noise modifier. •
The Plane primitive