Here is an excerpt from a post from Michael Comet from a few years ago. It uses the PointOnSurface-Node instead of a geometry-constraint.
In the MEL script editor type: createNode PointOnSurfaceInfo;
and hit Enter.
a new node should be made. In the outliner, you can turn off "show DAG objcts only" to find it at the bottom of the outliner list. By default it becomes what is currently selected.
Now what you have to do is to connect via the connection editor the info for the eye surface to the new posI node, and then that into a locator.
Load the posI node you just made into the right side of the connection editor. Select the eyesphere nurbs mesh, and hit the down arrow to select just the shape for it. Load the shape into the left side
of the connection editor.
Connect the eye nurbs shape "worldSpace[0]" into the posI nodes "inputSurface".
Now load the posI node onto the left side of the connection editor. Remember you can turn off "show DAG objects" only in the outliner
to find it.
Create a locator, and load it into the right side of the
connection editor.
Open up the "Result" section on the posI node left side of the connection editor, and connect the "Position" into the locators "Translate". The locator should jump to be somewhere on the eye.
The final step is to setup where the locator sits in UV space on the nurbs eye.
Select the posI node, and go to the attribute editor for it.
Check the box labeled "Turn On Percentage" to turn it on.
Now you can change the values in the "Parameter U" and "Parameter V" in the attribute editor, which will make the locator be position at that uv space on the nurbs eye surface.
Easy as mud...actually it's not too bad once you do it a few times, it's actually pretty simple. The hardest part is just getting the right values into the U/V positions.... which go from 0 to 1 by the
way...
If Geometry constraints actually worked/stuck properly...you wouldn't need all this....
-comet
Your eyes have to be Nurbs-Objects by the way.
Good luck with it.
Buzz
