robholder

Try dropping a 'Normal' node after each of the 'Retime' nodes in the tutorial. (Also, adding a 'Normal' node after the 'Subdivide' node for the un-shattered glass might help for the initial state's patches.)

The default 'Cusp Angle' value might be fine in terms of the major issues, but you could tweak the values to get the best results if you see that the 'Normal' node fix is working for you.