[Figures 51–53] Easy-to-read black-and-white maps used for unwrapping the UVs on an organic shape (above left, center). The grid map applied to the model (right).

2. Checkerboards or grids. These maps are useful in getting the excessive twisting and deformation out of the UV set in a model. The colored grid can be distracting to view and can hide many problems associated with UV work. By using a less distracting pattern that has evenly spaced partitions, the modeler can check for twisting and stretching much more easily.

[Figures 54 &55] A typical noise map (above). The noise map applied to the model (right).

3. Organic noise patterns. The noise map is the acid test for fine-tuning the UVs so there is no stretching. By the time the noise map is applied, there should be no overlapping UVs or twisted UVs; the noise map will not be able to help identify those problems. The noise map does one thing, but it does it well. The noise map shows stretching.

In the example shown in Figure 54, the noise map is applied to the model. This map in Figure 54 was generated in Photoshop using the texturizer filter in about a minute. In previous tests, the mapping seemed fine, and the stretching was minimal. After the noise map is used, the stretching in the ear and across the nose is easily apparent (Figure 55).

The stretching inside the mouth is really out of control, but that is an area that will not be seen, so it will normally not have to be as accurately mapped and modeled as the rest of the head.

It will be helpful to view these textures in realtime so rendering is only used for a final test. Real-time texture viewing will speed up the UV editing process dramatically. Unfortunately, procedural textures do not update in real time; they can only be viewed using a software render. Most graphics cards are optimized to accept bitmapped or file-based textures. A file that has a grid or checkerboard in it can be assigned to the model, and the file-based texture will update in realtime if the modeler is on a machine with a decent graphics card.