I'd like to thank one of our readers, Hamid, for sharing an update of sorts to the scene file I posted for tutorial #2. It has a pretty handy way of adding more and more objects to create the collision light up effect. You can find the file here.
Give it a spin and I hope it helps you out! You no longer would need to duplicate the Xpresso tag for every object that you want to collide and light up. Just duplicate the materials.
Learn how to utilize Xpresso to let dynamic collisions drive animation. In this sample, we use the collision of a cube object hitting the floor to drive the luminance brightness of its material, with a nice decay of brightness.
This tutorial is a bit dry, so if you already know Xpresso, you may want to just look at my cheat sheet below or download my scene file.
I apologize for the mistake at 17:12 in the tutorial. I said that when you divide by zero, you get zero. I meant to say, when you multiply by zero you get zero! If you have any questions or comments, please feel free. I am also looking for suggestions to make this a cleaner Xpresso rig.
Also, here are links to the other threads I got my idea from: