Civil Engineering Association

I would like to ask if anyone here had tried plotting stress contours in excel using its surface graphs. I wanted to plot stress contour of the soil bearing pressure of a rectangular footing with biaxial moment in excel. I had already found out all the necessary parameters of the footing like the location of the neutral axis & pressures of the corners. I just wanted to know how to do contour of the soil bearing pressure. 2D graphing would be fine as long as I can show the difference in pressures within the footing.

Any inputs, ideas and comments would be greatly appreciated.