It is hard to look at an image and determine whether or not it is tileable. However, it is quite easy to see why a non-tileable image is not tileable when it is tiled. Figure 3.1 shows an attempt to tile a non-tileable image.

Figure 3.1: A Non-Tileable Image

    Notice the visible seams above? If a large number of these textures were tiled together, the grid would be clearly visible. The goal of tiling is to create a seamless image, which covers the grid.

    Tileable images accomplish this goal. Figure 3.2 shows a tileable image being tiled.

Figure 3.2: A Tileable Image

    The above image has no noticeable seams. This is the advantage of using a tileable image.

    This chapter will now discuss how to create tileable images. The first step is to obtain an image to make tileable. Refer to Chapter 2 for some ideas on how to obtain images. The next step depends on what type of image is to be tiled. There are two general types of tileable images:

• Non-Patterned
• Patterned

    A non-patterned image is an image which does not contain a complex pattern that stretches across its entire surface. Grass or sand is a good example of a non-patterned image. A patterned image has complex, but repeatable, patterns. Bricks are a good example of a patterned image.