Making an equally spaced grid of points on an unrolled polysurface.

HI everyone , I am trying to make an equally spaced grid of points on an urolled polysurface from rhino and having a little problem . 
I created a bounding box for the unrolled polysurface , extracted a face that is co planar with it , divided it in a grid of points and then tried to use the closest point component  to  project those points on the  polysurface I need . Since my polysurface was trimmed  and did not match pefectly the face of the bounding box , I got points that were projected and made my grid uneven. I tried to cull those points based on the distance . My polysurface and the face of the bounding box were overlaping and I figured out that the only points I need would have a distance of 0 and I only needed to cull all the other ones to get the equally spaced grid , but I found out that  there were almost no points with the distance of 0 .

Could anyone explain me where is my mistake ? If my logic is not correct could you also tell me why ? Would appreciate any help !

I  attached the file with the internalised data and also a print screen . Thank you for your help !