how can I plot the intersection of two cylinders?

Hi, could someone tell me how to plot only the solid formed from the intersection of two cylinders? I've already plotted a 3D graph of the two figures in the first octant, but I just wanted the intersected solid.

I've attached the code I'm using, which I took from this link :

<https://in.mathworks.com/matlabcentral/answers/93623-how-do-i-plot-the-line-of-intersection-between-two-surfaces>

Answer 1

[DGM]

Like everything, there are probably better ways, especially to get the edges closed. The simple way is to just plot the surfaces and truncate them. Since the mesh is rectangular, so are the truncated edges.

% parameters
r = 2;
n = 1000; % number of points per axis

% only need one cylinder
[x1 y1] = meshgrid(linspace(-r,r,n));
z1 = sqrt(r^2 - x1.^2);
z2 = -sqrt(r^2 - x1.^2);

% truncate it
m1 = x1.^2 + y1.^2 > (r+r/n)^2;
z1(m1) = NaN;
z2(m1) = NaN;

% plot it and then plot a flipped copy
opts = {'specularstrength',0.5,'ambientstrength',0.4,'diffusestrength',0.9};
surf(x1,y1,z1,opts{:}); hold on;
surf(x1,y1,z2,opts{:})
surf(x1,z1,y1,opts{:})
surf(x1,z2,y1,opts{:})

axis equal
shading flat
colormap(ccmap)
lightangle(240,60)
lighting gouraud

[Eduardo Fornazieri]

In this case, what can I do to plot only positive values ​​of x, y, and z? (first octant). Thank you, this code is way better than mine.