Use Universal Deformation Technology to deform objects
http://docs.mcneel.com/rhino/5/help/en-us/seealso/sak_udt.htm
Flatten curves and surfaces
http://docs.mcneel.com/rhino/5/help/en-us/index.htm#seealso/sak_flatten.htm?Highlight=squish
Rhino V5 Help (ja-jp)
http://docs.mcneel.com/rhino/5/help/ja-jp/index.htm