If I understand you correctly, you have a list of vertices and an array that specifies how to connect them into triangles. If you want to visualize this, you can supply this information to the patch command. That information can be used to set the patch object's Vertices and Faces properties.
Here's a simple example -- four vertices are being used to construct 2 triangles:
% vertex locations -- each row is an (x,y) pair. It can also
% be an (x,y,z) triple, but I'll do 2D here for simplicity.
vertices = [ 1 1; 2 2; 1 3; 2 4 ]
% This describes how the vertices connected.
tris = [ 1 2 3; 2 4 3 ]
% Make a patch
patch( 'Vertices', vertices, 'Faces', tris, 'FaceColor', 'r' );