I'm wanting to plot a 3D XYZ scatter graph (surface) but couldn't out a way to do it in excel.

Do you know how I can go about it? If it's not possible in excel is there some free software that I can download that will do the job?

To make the porblem clear, we measured the height of water at different points in a river ( height difference due to surface waves or ripples) and we know the exact position of the points with respect to an origin. We were looking at plotting a 3D graph to simulate the river surface.

It will be great if anyone could help!

Cheers