Game Development Reference
Fig 1.13 The UV mapping process.
Vertices of a polygon on an object are
mapped to locations on a 2D image.
mapping . This aligns points on an image with vertices of each polygon.
The part of the image between the points is then stretched across the
polygon. This process is shown on a square polygon in Figure 1.13 .
To add a tactile look to the surface of a polygon enhancing the base texture,
bump mapping is applied. This gives the object an appearance of having
bumps, lumps, and grooves without the actual model itself being changed.
Bump mapping is often applied to add more depth to an object with respect
to the way light and shadow display on the surface. Figure 1.14 illustrates the
application of a color and normal map on a soldier mesh taken from Unity.
A variety of other effects also add further texture to a surface. For example,
specular lighting can make an object look glossy or dull, and shaders , small
programs that manipulate the textures on a surface, can add a plethora of
special effects from bubbling water to toon shading. A closer look at these
will be included in later chapters.
In the theory of visual art involving pigments, color is taught as a set of
primary colors (red, yellow, and blue) from which all other colors can be
created. The color perceived by the human eye is the result of light being