Quartz composer is often used for making screensavers. So, to learn QC, I decided to make a screensaver of my own. I started with a simple concept, two spheres orbiting around each other. I thought it would be simple anyway. All of the motion is accomplished through the use of LFOs (low-frequency oscillators). At first, I thought I could use three LFOs, one for each axis, to generate the desired motion. I couldn’t find anyway to get this to work. In the end, I found an alternative solution. Each sphere has two LFOs that cause the sphere to orbit in the yz-plane. From there, I used a 3D transformation patch to rotate the two spheres about the y and z axes. This achieved the movement I mentally envisioned. Much of my efforts were trial and error. There is very little documentation available for QC. I hope this to change in time.
Below is a link to my Quartz Composition for anyone interested.
http://dl.dropbox.com/u/2998162/Quartz%20Composer/Orbiting_Spheres.qtz
