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Video Game Design Foundations
An orange is a good example
of a UV sphere. A UV sphere uses
slices like the segments of an orange
to make the object round, as shown
in Figure 4-34. The more slices
(segments), the more rounded
the sphere appears. Imagine the
segments of the orange as the faces of
the UV sphere. The peel of the orange
is the texture map stretched over the
sphere. The texture map provides the
orange color and the wrinkly quality
of the peel. Brown spots and irregular
flaws added to the texture map will
make the image more realistic.
Another type of sphere is a
geodesic sphere.
Instead of rectangular and
triangular faces, a geodesic sphere has faces of regular polygons. This is the
way a soccer ball is made, as illustrated in Figure 4-35. There are different
types of geodesic spheres. For example, an icosphere is based on a 20-sided
object. Its faces are equilateral triangles.
Think about the example of the orange and
the soccer ball as a UV sphere or a geodesic
sphere. Come up with two other examples
each for UV sphere and geodesic sphere.
UP!
4.5
Figure 4-34.
Shutterstock.com
The segments of an orange are fit
together to approximate a round shape.
Notice how the segments relate to the
sphere shown in Figure 4-33B.
Figure 4-35.
Shutterstock.com; Goodheart-Willcox Publisher
A—Notice the black and white shapes on the surface of the soccer
ball. These are regular polygons fit together to simulate a round shape.
B—Notice the faces on the geodesic sphere. In this example, they are
regular triangles. These are fit together to approximate a round object.