2 variable surface plot with isoline

Hello, my question is if there is a way to put an isoline on an existing surface plot.

For example I have this surface plot

fsurf(@(x1,x2) sin(x1)^2 -0.2*x1*x2,[0 6]) (please rotate the view for better understanding)

Now, on this surface, I want to add a black line where the following plane intersects (hopefully I make sense)

hold on

fsurf(@(x1,x2) sin(x1)^2 -0.2*x1*x2==0,[0 6])

But I do not need the whole plane added.

Any ideas please?

[Emmanouil Karamousadakis]

Thank you!

Looks great!

Answer 1

[Chunru]

[x, y] = meshgrid(0:.1:6, 0:.1:6);
z = sin(x).^2 -0.2*x.*y;  
s = surfl(x, y, z);
s.EdgeColor = 'none';
view(-120, 30)
hold on
contour3(x, y, z, [0 0], 'r-')