Image mapping on SolidWorks

I had to make an old wrapped bill look-alike model pierced with a spear and the problem i got was that whenever i used flex or deform commands on SolidWorks the mapping would just not follow the model deflections. How do i make it to stick with the model no matter how i manipulate the model after projecting the image on it?
P.S i tried to add it as a decal and same thing was happening .