libigl_Martin/python/tutorial/302_Sort.py

#!/usr/bin/env python
#
# This file is part of libigl, a simple c++ geometry processing library.
#
# Copyright (C) 2017 Sebastian Koch <s.koch@tu-berlin.de> and Daniele Panozzo <daniele.panozzo@gmail.com>
#
# This Source Code Form is subject to the terms of the Mozilla Public License
# v. 2.0. If a copy of the MPL was not distributed with this file, You can
# obtain one at http://mozilla.org/MPL/2.0/.
import sys, os

# Add the igl library to the modules search path
sys.path.insert(0, os.getcwd() + "/../")
import pyigl as igl

from shared import TUTORIAL_SHARED_PATH, check_dependencies

dependencies = ["glfw"]
check_dependencies(dependencies)


V = igl.eigen.MatrixXd()
F = igl.eigen.MatrixXi()

igl.readOFF(TUTORIAL_SHARED_PATH + "decimated-knight.off", V, F)

# Sort barycenters lexicographically
BC = igl.eigen.MatrixXd()
sorted_BC = igl.eigen.MatrixXd()

igl.barycenter(V, F, BC)

I = igl.eigen.MatrixXi()
J = igl.eigen.MatrixXi()

# sorted_BC = BC(I,:)
igl.sortrows(BC, True, sorted_BC, I)

# Get sorted "place" from sorted indices
J.resize(I.rows(), 1)
# J(I) = 1:numel(I)

igl.slice_into(igl.coloni(0, I.size() - 1), I, J)

# Pseudo-color based on sorted place
C = igl.eigen.MatrixXd()
igl.jet(J.castdouble(), True, C)

# Plot the mesh with pseudocolors
viewer = igl.glfw.Viewer()
viewer.data().set_mesh(V, F)
viewer.data().set_colors(C)
viewer.launch()