I end this introduction to Photoshop's filters with a few demonstrations of how you can combine filters with layer styles to produce some very impressive visual effects. During the course of these examples, I introduce you to some other effects filters that I may not have specifically covered in the earlier sections of this chapter.
The techniques in these examples make heavy use of such principles as layer styles, layer masks, blending modes, and levels. It might be worth it to do a quick review of some of the earlier chapters of this book that cover these topics.
Photoshop has two built-in filters that create random cloud patterns — the Clouds and Difference Clouds filters, located under the FiltersRender menu. Neither of these filters used by itself produces satisfying results if you're looking to produce realistic clouds, but they can be useful as a starting point.
The Clouds filter generates a random pattern that varies between the foreground and background color. Set your foreground and background color and choose FilterClouds to fill the current layer or selection with the cloud pattern. The contents of the current layer will be replaced by the pattern, so create an empty layer if necessary.
The Difference Clouds filter works slightly ...