Store 3d coordinates in a 2d image? How can i store the X,Y,Z vertex points of a mesh into a 2d image, such that reading the image pixel values will correspond to the 3d coordinates? is it possible to just store x, y, values on a grid and use the Z value as an intensity value?
The most straightforward way would be to put x into the red channel, y into the green channel, and z into the blue channel of each pixel. 

You could also make a 1 channel image where intensity is used to describe height. This is called a height map. Usually the x and y of the mesh are the same as the x and y of the image, so no need to store them in any way.