Tube-Plot with x-y-Coordinates and radius

Hi!

I'm looking for a function, which can plot me a tube around a line.

I will draw a various line with some points i picked with my mouse in a gui and after that, the line should be a tube. Anyone an idea how to do that?

Answer 1

[Roger Stafford]

Let P1 and P2 be 1 x 3 row vectors of the x, y, z coordinates of two points along your line and let r be the desired radius.

 u = P2-P1;
 t = r*null(u)';
 v = t(1,:); w = t(2,:);
 m = 32; n = 85;
 [S,T] = meshgrid(linspace(0,1,m),linspace(0,2*pi,n));
 S = S(:); T = T(:);
 P = repmat(P1,m*n,1) + S*u + cos(T)*v + sin(T)*w;
 X = reshape(P(:,1),n,m);
 Y = reshape(P(:,2),n,m);
 Z = reshape(P(:,3),n,m);
 surf(X,Y,Z)

This should plot the surface of a cylindrical surface of radius r about the line segment P1P2. Hopefully you can adapt the code to your needs.