origami surface

Hi Panagiotis and Sawako,

first of all, thank you so much for sharing your amazing plug-in! It is so exciting and I love the graphics too :)

I'm trying to have the structural analysis for folded surface, but i had some problems. 

If i design that with the frames , it's ok. if i try to model it with the mesh, the result isn't very good... 

what's wrong!?