This post will only be of interest to anybody using the zoo space switching system which is integrated into Hamish McKenzie's zooCST and packaged with the zooToolbox. I recently added a zoo space switching walkthrough to the list of articles I have been writing about the zooToolbox, so I thought I would also add a post here about an extra feature I added to zoo space switching to make animating it easier.
A common approach to rendering is to do it in several passes and to composite them using something like after effects or fusion. For me an important pass is a variation on the standard depth pass, which I refer to as the depth-of-field pass. For a few years I have rendered the depth-of-field pass using a wonderful mentalray shader called zDepthDOF by Andreas Bauer. (The link takes you to a good explanation of how the shader works and why it is better than a standard depth render.)
The thing I like most about zDepthDOF is that I can use it with the maya distance tool. I connect the distance attribute to the shader's focus distance parameter. I point-constrain one of the distance tool's locators to the camera. Then I animate the other locator to accurately control the focal point in my depth pass which can then be used to create some nice focus change effects using an after effects filter like the compound blur.
But zDepthDOF is a mentalray shader, so just for fun I decided to see if I could do the same thing using the standard maya software renderer. It wasnt too difficult and I thought it might worth sharing. It's a great example of how the maya utility nodes can be used in a shader network.