There are several pre-defined commands that allow for quick rendering of spheres, cylinders, and disks. The advantage of these commands is not only their ease-of-use, but that they have special lighting properties (their “normals”) built in.
The following commands are used to construct cylinders, disks, partial disks, and spheres.
Cylinder( baseRadius, topRadius, height, slices, stacks )
baseRadius is the radius of the cylinder’s base. Similarly, topRadius is the radius of the top. height is the height of the cylinder.
Slices can be 10 for a reasonably accurate cylindrical shape. Using QuadricNormals(Smooth) helps the appearance.
Stacks sets the number of vertices available for lighting reflections. Use a larger value for Stacks for accurate “hot-spots”.
The following command draws a paper-thin disk with an innerRadius hole in the middle.
Disk( innerRadius, outerRadius, slices, loops )
Like Cylinder, slices controls the accuracy of the curve and loops makes more vertices (for lighting accuracy).
Partial Disk( innerRadius, outerRadius, slices, loops, startAngle, sweepAngle )
The Partial Disk command works like Disk, but with a slice of the disk removed. Specify the part of the disk that is showing using startAngle and sweepAngle.
The following command draws a sphere with the specified radius.
Sphere( radius, slices, stacks )
The slices can be thought of as longitudes and stacks as latitudes. About 10 of each make a nicely drawn sphere.