Remove Unconnected Triangle

This function takes a triangulation and remove the unconnected cells. The group of cells to keep can be specified with an index of triangle contained in this group. If no triangle index is specified, the filter will keep the group with the maximum number of cells.

Input :
"XYZ1" is nx3 matrix which are vertices coordinates
"TRI1" is mx3 matrix which are the standard indexes vertices "triID" is a triangle index of "TRI1" contained on the group of cells to keep. (optionnal)

Output :
"XYZ2" is px3 matrix which are vertices coordinates of output
"TRI2" is qx3 matrix which are the standard indexes of vertices

Simple example :

X=[2 1 3 2 5 5 8 6 7 5 8 9 10 12 10 12 13 15 1 0 2 1];
Y=[2 4 4 6 6 8 8 4 2 2 4 6 8 7 5 5 3 2 7 8 8 9];
Z=zeros(size(X));
TRI=[1 2 3;2 4 3;4 3 5;5 6 7;10 8 9;8 9 11;12 13 14;15 16 17;17 16 18;4 6 5;20 19 21;22 21 20];
[TRI2 XYZ2]=removeUnconnectedTri(TRI,[X' Y' Z']);

subplot(2,1,1)
trisurf(TRI,X,Y,Z), title('Before filter')
axis([min(X) max(X) min(Y) max(Y)]);
campos([7.5 6 10])
camtarget([7.5 6 0])
subplot(2,1,2)
trisurf(TRI2,XYZ2(:,1),XYZ2(:,2),XYZ2(:,3)), title('After filter')
axis([min(X) max(X) min(Y) max(Y)]);
campos([7.5 6 10])
camtarget([7.5 6 0])