From the looks of things here, there’s not much special going on. The only important thing to note is that the Suzanne head has a constraint on it. However, you can Grab (G) and move the head around all you want. But, select the circle object (right-click) and Tab into Edit mode. There should be a single vertex selected right where the Suzanne head is. That vertex is the sole member of a vertex group call Group. If you Grab (G) that vertex and move it around, the Suzanne head will follow it.

Files:

• childof_vertex.blend

Here’s a good real-world application of constraints. The camera has two constraints on it: a Follow Path constraint to lock it to the curve circle, and a Track To constraint to keep it always pointing at Suzanne. This is a really nice way to get an spinning table top animation for presenting your models.

Files:

• cameratrack.blend