Flatten mesh with no distortion I am using Blender as the basic 3d tool to design the paper craft (like origami, but with die-cut). 
My question is that is it possible for me to flatten the mesh with the polygon undistorted? So that I can print it out on paper and reconstruct the 3d model.
If I understand your question, it seems the Export Paper Model would do it fully automatically. Related Blender Artists thread.

This addon will export an SVG of the flattened model.



It works well for most shapes, you even get extra flaps for sticking. Note the outward surfaces will generally not overlap, if there is overlapping it is only the stick-lips.

This:



becomes this: