Think I have something here. This demo shows my last progress om the directional phong shading.
It start looking good, performance seams ok, while i have not even tried yet to improve code on speed.

In this case my light definition is not defined as it should, has no radius, as a result lightning comes equally projected onto the models.
So I think I know where I should focus...

I must say I'am very pleased about this result. Specially the information of smooth shadow enhance greatly the visuals...
Hope to post soon more... and i'll try to use something else than that turtle model!