Draw axis on 3D-object surface

The following code produces a 3D box-surface with a bar in the middle:

img = zeros(100,100)+5;
img(1,:)=0;
img(end,:)=0;
img(:,1)=0;
img(:,end)=0;

img(50,50) = 120;

surf(img);
shading interp
axis tight

I'm wondering how I can draw x- and y-axis directly on the top-surface (the blue surface) of the box, and the ticks pointing inwards?

Also I notice that the z-axis is difficult to match with the height of the middle bar. I'm wondering what's the best way to put the z-axis or a way to represent the height of the middle bar?

Answer 1

[Star Strider]

Ticks pointing inwards is easy. See 'TickDir' for details. You may not be able to see them though, if you do that.

The rest I doubt you can do, at least easily. Search the File Exchange to see if some of those contributions can do what you want.