Select points of a surface

I have a question,

Is it possible to select point on a surface??

I am doing a chains of a jewellery piece, and I tried to select the inner quadrant point or the outer quadrant point of the jump ring, but I fail.

Is there ways to select points on a surface ?

58 AM

select _point, then activate the snap surface or polysurface. Alternatively, draw a curve with the _ExtractIsocurve command and then use the _point command and then snap curve

-Simon

Thank you !!!

BTW, I have another question,

How to set a white background instead of gird background ?

like this

ott-17-2017 08-20-12

Thank you very much!!