libigl_Martin/python/tutorial/105_Overlays.py

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 = ["viewer"]
check_dependencies(dependencies)


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

# Load a mesh in OFF format
igl.readOFF(TUTORIAL_SHARED_PATH + "bunny.off", V, F)

# Find the bounding box
m = V.colwiseMinCoeff()
M = V.colwiseMaxCoeff()

# Corners of the bounding box
V_box = igl.eigen.MatrixXd(
    [
        [m[0, 0], m[0, 1], m[0, 2]],
        [M[0, 0], m[0, 1], m[0, 2]],
        [M[0, 0], M[0, 1], m[0, 2]],
        [m[0, 0], M[0, 1], m[0, 2]],
        [m[0, 0], m[0, 1], M[0, 2]],
        [M[0, 0], m[0, 1], M[0, 2]],
        [M[0, 0], M[0, 1], M[0, 2]],
        [m[0, 0], M[0, 1], M[0, 2]]
    ]
)

E_box = igl.eigen.MatrixXi(
    [
        [0, 1],
        [1, 2],
        [2, 3],
        [3, 0],
        [4, 5],
        [5, 6],
        [6, 7],
        [7, 4],
        [0, 4],
        [1, 5],
        [2, 6],
        [7, 3]
    ]
)

# Plot the mesh
viewer = igl.viewer.Viewer()
viewer.data.set_mesh(V, F)

# Plot the corners of the bounding box as points
viewer.data.add_points(V_box, igl.eigen.MatrixXd([[1, 0, 0]]))

# Plot the edges of the bounding box
for i in range(0, E_box.rows()):
    viewer.data.add_edges(
        V_box.row(E_box[i, 0]),
        V_box.row(E_box[i, 1]),
        igl.eigen.MatrixXd([[1, 0, 0]]))

# Plot labels with the coordinates of bounding box vertices
l1 = 'x: ' + str(m[0, 0]) + ' y: ' + str(m[0, 1]) + ' z: ' + str(m[0, 2])
viewer.data.add_label(m.transpose(), l1)

l2 = 'x: ' + str(M[0, 0]) + ' y: ' + str(M[0, 1]) + ' z: ' + str(M[0, 2])
viewer.data.add_label(M.transpose(), l2)

# Launch the viewer
viewer.launch()