In this six minute video tutorial you’ll learn how to create a custom render tree that will control the value of parameter (decay) based on the distance from the camera.
This is essential to controlling displacement maps for deep landscapes, or for special effects, like changing the color of the ground in front of the camera. Your imagination should go wild with ideas on how to apply this technique once you have a functioning render tree. In fact, with Autodesk Softimage 2011 you can create a compound of this render tree, and use it as a render tree node. You can make it once, and then reuse it many more times afterward.