Download Dispersing Glass.mat
The second method utilizes a:m's frame subsampling for Multipass Motion Blur.
It yields a much cleaner result, but Motion Blur will have to be set to 100%.
the setup is like this:
Have an action for your dispersing Object called "disperser".
Select "show more than drivers" for the model shortcut in the scrion.
Key the Refraction to 1.3 at Frame 0 and to 1.7 at Frame 12
Key the color something like this to form a spectrum:
Create a Chor with the model, add the disperser action to the model.
Set the Action Shortcuts' Cycle Length to 1 and Repeat to 10.
Render Frame 2 to File with Multipass=ON, Passes=64 (you can go lower than that), Motion Blur=100%.
Download DispersionWithMoBlur.prj
The third method takes elements of both previously described ones.
2 GradientZ:Textures are needed. Both take "Frame Subsampling Time" as input.
The first outputs to Refraction, the second outputs a spectrum to Diffuse Color.
Render Frame 2 to File with Multipass=ON, Passes=64 (you can go lower than that), Motion Blur=100%.
This method will give about the same results as method 2.
Advantages: You need no action. Material level slution. Visual control for gradient. You can easily reduce Motion Blur to a normal value like 25% by applying a compensating transformation to the input.
Disadvantage: it will render slower.