# Special Coloring of two 3D Graphics with same values

As you can see in the picture below, I have plotted three different functions. Since two functions (red and blue) have the same value for a certain region (equity > 60), I was wondering how I can make it look more intuitiv for the observer that the values are the same. I was thinking of an pattern in red and blue or something similar. • Could you provide a code to work with? A minimal example. – Kuba Jan 20 '16 at 18:42

You could do this for example :

gr00 = Plot3D[x^4, {x, 0, 1}, {y, 0, 1}, MeshFunctions -> {#1 + #2 &},
Mesh -> 30];
gr01 = Plot3D[0, {x, 0, 1}, {y, 0, 1}, MeshFunctions -> {#1 - #2 &},
Show[gr00, gr01] There is a lattice in the zone where the curves are considered as "equals".
I don't know what's the "equality" criterion (it depends on the ViewPoint, it is implemented in the 3D rendering engine).

One can play with Opacity[] too :

gr00 = Plot3D[x^4, {x, 0, 1}, {y, 0, 1}, MeshFunctions -> {#1 + #2 &},
Mesh -> 30, MeshShading -> {Directive[Opacity[0.9], Yellow]}];
gr01 = Plot3D[0, {x, 0, 1}, {y, 0, 1}, MeshFunctions -> {#1 - #2 &},
Show[gr00, gr01] Following @andre... but don't forget to set the ViewPoint to reveal the overlap of the functions in question:

gr00 = Plot3D[x^4, {x, 0, 1}, {y, 0, 1},
MeshFunctions -> {#1 + #2 &},
Mesh -> 40, 