Learn Three.js - Third Edition

Using PointConstraint to limit movement between two points

If you open the 04-point-contstraint.html example, you see the following:

In this example, we rendered a horizontal bar on which a chain of beads is dropped. When you open this example, you can see that the beads curl themselves around the bar, before falling out of the screen. This happens because each bead uses a PointConstraint to keep a certain distance to its neighbor. So, as soon as one side is heavier then the other, gravity and this constraint will make sure the chain slides over the horizontal bar.

The PointConstraint objects in this example are created as follows:

function ...