Delaunay Triangulation of 3-D Points
Create and plot the Delaunay triangulation of 3-D points by using delaunayTriangulation.
rng("default")
P = rand(30,3);
DT = delaunayTriangulation(P)DT =
delaunayTriangulation with properties:
Points: [30×3 double]
ConnectivityList: [102×4 double]
Constraints: []
faceColor = [0.6875 0.8750 0.8984]; tetramesh(DT,FaceColor=faceColor,FaceAlpha=0.3)

The tetramesh function plots both the internal and external faces of the triangulation. For large 3-D triangulations, plotting the internal faces might be an unnecessary use of resources. A plot of the boundary might be more appropriate. You can use the freeBoundary method to get the boundary triangulation in matrix format. Then pass the result to trimesh or trisurf.