3d plot

Question

developer 2011-9-14

Hello,

dt = DelaunayTri(x,y);
figure
triplot(dt);
hold on  
t = vertexAttachments(dt,1);
triplot(dt(t{:},:),x,y,'Color','r');
hold off

This is if i have x and y, how can i do it for x,y and z?

Thanks in advance

Answer 1

Andrew Newell 2011-9-14

EDIT: Define U=[x(:) y(:) z(:)], then use

dt = DelaunayTri(U);

Plot it using a command like

tetramesh(dt, 'FaceColor', 'cyan');

EDIT 2: Here is an example in which the vertex attachments for vertex 1 are highlighted.

x = rand(20,1); y = rand(20,1); z=rand(20,1);

Plot all the tetrahedra.

U=[x(:) y(:) z(:)];
dt = DelaunayTri(U);
h=tetramesh(dt, 'EdgeColor', 'cyan','FaceColor','none'); hold on

Find simplex attachments and extract the vertex numbers

t = vertexAttachments(dt,1);
tri_attach = dt.Triangulation(t{:},:);
ii = unique(tri_attach(:));

Now plot the tetrahedra for the attached vertices

U = U(ii,:);
dt = DelaunayTri(U);
tetramesh(dt, 'EdgeColor', 'red','FaceColor','none');

developer 2011-9-15

But its only for 'dt' i guess not for the vertex attachment portion 't'?

developer 2011-9-15

you have used tetramesh for showing 'dt' but not 't'