(Not recommended) Free boundary facets
freeBoundary(TriRep) is not recommended. Use
TriRep is not recommended. Use
TriRep to compute the boundary triangulation of an imported triangulation.
Load a 3-D triangulation.
load tetmesh; trep = TriRep(tet,X);
Compute the boundary triangulation.
[tri,xf] = freeBoundary(trep);
Plot the boundary triangulation.
trisurf(tri,xf(:,1),xf(:,2),xf(:,3), ... 'FaceColor','cyan','FaceAlpha',0.8)
Perform a direct query of a 2-D triangulation created with
Create a Delaunay triangulation.
x = rand(20,1); y = rand(20,1); dt = DelaunayTri(x,y);
Compute the free boundary of the triangulation, and then plot the triangulation with the free boundary edges in red.
fe = freeBoundary(dt)'; triplot(dt) hold on plot(x(fe),y(fe),'-r','LineWidth',2) hold off
In this instance the free edges correspond to the convex hull of (x,y).
TR— Triangulation representation
Triangulation representation, specified as a
FF— Free boundary facets
Free boundary facets, returned as a matrix.
FF is of size
m is the number
of boundary facets and
n is the number of vertices per facet. The
vertices of the facets index into the array of points representing the vertex
TR.X. The array
FF could be empty as
in the case of a triangular mesh representing the surface of a sphere.
XF— Vertex coordinates of free boundary facets
Vertex coordinates of free boundary facets, returned as a matrix.
XF is of size
m is the number of free facets, and
the dimension of the space where the triangulation resides.
A simplex is a triangle/tetrahedron or higher-dimensional equivalent.
A facet is an edge of a triangle or a face of a tetrahedron.