Object with irregular form

hi,
do I have to create an object where to put a texture video, the form of this object it is not regular, as can I proceed?
the form should be adjustable through vvvv, a mask of transparency it doesn’t go, well because the contour I have to draw it on the place while I am projecting it.

thanks

maybe rebuild the object in 3d editing software. export it as an x-file and after that modify it as done in

girlpower+ Dynamic Mesh\MeshEditor Sample.v4p