libigl_Martin/python/301_Slice.py

from __future__ import print_function
import igl
from iglhelpers import *

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

igl.readOFF("../tutorial/shared/decimated-knight.off",V,F)

temp  = igl.eigen.MatrixXd()

# 100 random indicies into rows of F
temp.setRandom(100,1)

I = igl.eigen.MatrixXi()
igl.floor((0.5*(temp+1.)*F.rows()),I);

# 50 random indicies into rows of I
temp.setRandom(50,1)
J = igl.eigen.MatrixXi()
igl.floor((0.5*(temp+1.)*I.rows()),J)

# K = I(J);
K = igl.eigen.MatrixXi()
igl.slice(I,J,K)

# default green for all faces
C = p2e(np.array([[0.4,0.8,0.3]])).replicate(F.rows(),1)

# Red for each in K
R = p2e(np.array([[1.0,0.3,0.3]])).replicate(K.rows(),1)
# C(K,:) = R
igl.slice_into(R,K,1,C)

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