Problem using boundary and trisurf functions to create a mesh with three points

Hi, I am having some difficulties using these functions. I have three points and I would like to create a mesh with them, if I have four points these work perfectly but when I only insert three points boundary returns and empty matrix. I would like to know whats wrong and if there is anyway I can fix it. What I want is to create a surface between those three points, maybe there is another way to do it but I cant figure it out. Thanks!

p(1,1) = -26,9030200000000;

p(1,2) = 74,5056900000000;

p(1,3) = 1,76957800000000

p(2,1) = -31,3498700000000;

p(2,2) = 71,4396500000000;

p(2,3)= 26,4499500000000;

p(3,1) = 26,9030200000000;

p(3,2) = 74,5056900000000

p(3,3) = 1,76957800000000;

k = boundary(p)

hold on

trisurf(k,p(:,1),p:,2),p(:,3),'Facecolor','red','FaceAlpha',1)

%'EdgeColor', 'none')

grid off

Answer 1

[John D'Errico]

You have THREE points, in a 3 dimensional space.

How many points determine a volume in 3-d? 4. Essentially, a tetrahedron in 3 dimensions is as simple as you can get. So if you have only 3 points, they determine a triangle. But they are not sufficient to determine a tetrahedron. And you certainly will not create a boundary surface in 3-d.

If your goal is as simple as creating a surface that spans those 3 points, then this is simple. Just use patch.

patch(p(:,1),p(:,2),p(:,3),'r')
box on
grid on