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igl/python/tutorial/504_NRosyDesign.py
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2018-11-28 08:29:23 -05:00

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#!/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
from math import atan2, pi, cos, sin
# 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 = ["comiso", "glfw"]
check_dependencies(dependencies)
# Mesh
V = igl.eigen.MatrixXd()
F = igl.eigen.MatrixXi()
# Constrained faces id
b = igl.eigen.MatrixXi()
# Constrained faces representative vector
bc = igl.eigen.MatrixXd()
# Degree of the N-RoSy field
N = 4
# Converts a representative vector per face in the full set of vectors that describe
# an N-RoSy field
def representative_to_nrosy(V, F, R, N, Y):
B1 = igl.eigen.MatrixXd()
B2 = igl.eigen.MatrixXd()
B3 = igl.eigen.MatrixXd()
igl.local_basis(V, F, B1, B2, B3)
Y.resize(F.rows() * N, 3)
for i in range(0, F.rows()):
x = R.row(i) * B1.row(i).transpose()
y = R.row(i) * B2.row(i).transpose()
angle = atan2(y[0], x[0])
for j in range(0, N):
anglej = angle + 2 * pi * j / float(N)
xj = cos(anglej)
yj = sin(anglej)
Y.setRow(i * N + j, xj * B1.row(i) + yj * B2.row(i))
# Plots the mesh with an N-RoSy field and its singularities on top
# The constrained faces (b) are colored in red.
def plot_mesh_nrosy(viewer, V, F, N, PD1, S, b):
# Clear the mesh
viewer.data().clear()
viewer.data().set_mesh(V, F)
# Expand the representative vectors in the full vector set and plot them as lines
avg = igl.avg_edge_length(V, F)
Y = igl.eigen.MatrixXd()
representative_to_nrosy(V, F, PD1, N, Y)
B = igl.eigen.MatrixXd()
igl.barycenter(V, F, B)
Be = igl.eigen.MatrixXd(B.rows() * N, 3)
for i in range(0, B.rows()):
for j in range(0, N):
Be.setRow(i * N + j, B.row(i))
viewer.data().add_edges(Be, Be + Y * (avg / 2), igl.eigen.MatrixXd([[0, 0, 1]]))
# Plot the singularities as colored dots (red for negative, blue for positive)
for i in range(0, S.size()):
if S[i] < -0.001:
viewer.data().add_points(V.row(i), igl.eigen.MatrixXd([[1, 0, 0]]))
elif S[i] > 0.001:
viewer.data().add_points(V.row(i), igl.eigen.MatrixXd([[0, 1, 0]]));
# Highlight in red the constrained faces
C = igl.eigen.MatrixXd.Constant(F.rows(), 3, 1)
for i in range(0, b.size()):
C.setRow(b[i], igl.eigen.MatrixXd([[1, 0, 0]]))
viewer.data().set_colors(C)
# It allows to change the degree of the field when a number is pressed
def key_down(viewer, key, modifier):
global N
if ord('1') <= key <= ord('9'):
N = key - ord('0')
R = igl.eigen.MatrixXd()
S = igl.eigen.MatrixXd()
igl.comiso.nrosy(V, F, b, bc, igl.eigen.MatrixXi(), igl.eigen.MatrixXd(), igl.eigen.MatrixXd(), N, 0.5, R, S)
plot_mesh_nrosy(viewer, V, F, N, R, S, b)
return False
# Load a mesh in OFF format
igl.readOFF(TUTORIAL_SHARED_PATH + "bumpy.off", V, F)
# Threshold faces with high anisotropy
b = igl.eigen.MatrixXd([[0]]).castint()
bc = igl.eigen.MatrixXd([[1, 1, 1]])
viewer = igl.glfw.Viewer()
# Interpolate the field and plot
key_down(viewer, ord('4'), 0)
# Plot the mesh
viewer.data().set_mesh(V, F)
viewer.callback_key_down = key_down
# Disable wireframe
viewer.data().show_lines = False
# Launch the viewer
viewer.launch()