Snapping Edit Points of a Curve to a Live object
I'm trying to create a patch modelled head as described in the book Maya Character Creation. I've built a polygon copy of the head which I've made a live surface in order to draw the curves to make the patches with. Drawing a curve on the surface does snap to the live surface correctly. However when I modify any duplicate curves and move the edit points of the new curve it won't snap to the live object at all. Is there a pref setting or something I need to check ? I've deleted all the history from the duplicate curves, and the head, and its still not working.
Anyway, I have also tried to create patches by just creating curves and then using Surfaces>Square but whenever I do I get a SqrSurf error saying that my first and second curves don't intersect, what is causing that ? I've tried forcing them to intersect by dragging them through each other, and by snapping their endpoints together and I'm still getting the same error. Help!