Form the clay into the forms or characters you desire. Set up your lamp outside of your webcam's frame but so it still gives consistent light to your "set" in front of the camera. Place your clay objects on the set to see how the lighting looks on them. It is important to make your lighting choices and adjustments before you start shooting.
Open the animation software you have downloaded. If your webcam is not built into your computer, be sure that it is on and connected properly to your computer. Open a new project in your software.
Adjust your camera so that you can see the objects you wish to animate within the frame.
Put your clay objects into the position you would like them to start in. Make sure all unwanted objects are out of the frame and click the "Capture" (or similarly labeled) button in your software.
Adjust your clay object very slightly in the direction your wish it to move. Click "Capture" in your software. Remember that 12 captures equals one second of video, so the smaller the adjustments, the smoother the motion.
Select "Save" from the "File" menu when you have completed your scene. Select a memorable name and location for your project and then click "Save" to complete.