Hi all, I tried to create a convex hull of a set of points distributed on a cylindrical surface by the following script. The needed input file coor.dat is attached. How can I fix the problem with the distorted mesh (convex.png) ? Nils from scipy.spatial import Delaunay import numpy as np points = np.loadtxt('coor.dat',usecols =(1,2,3)) nid = np.loadtxt('coor.dat',usecols=(0,)) m,n = points.shape print 'Number of points m =', m tri = Delaunay(points) faces = [] for ia, ib, ic in tri.convex_hull: x1 = points[ia] x2 = points[ib] x3 = points[ic] area = 0.5*np.linalg.norm(np.cross(x2-x1,x1-x3)) print 'Area of face', area faces.append(points[[ia, ib, ic]]) import matplotlib.pyplot as plt from mpl_toolkits.mplot3d import Axes3D from mpl_toolkits.mplot3d.art3d import Poly3DCollection fig = plt.figure() ax = fig.gca(projection='3d') items = Poly3DCollection(faces, facecolors=[(0, 0, 0, 0.1)]) ax.add_collection(items) ax.scatter(points[:,0], points[:,1], points[:,2], 'o') ax.legend(loc=0,shadow=True) plt.show()