Voxelization

0. Initialization

Importing all necessary libraries and specifying the inputs

import os
import topogenesis as tg
import pyvista as pv
import trimesh as tm
import numpy as np

#setting the specified voxel size
vs = 16.20
unit = [vs, vs, vs]
mesh_path = os.path.relpath('../data/optional_envelope.obj')

1. Input Mesh

# load the mesh from file
mesh = tm.load(mesh_path)
# Check if the mesh is watertight
print(mesh.is_watertight)

# Visualize the mesh using pyvista plotter

# initiating the plotter
pv.set_plot_theme("document")
p = pv.Plotter(notebook=True)

# convert mesh to pv_mesh
faces = np.pad(mesh.faces, ((0, 0),(1,0)), 'constant', constant_values=3)
pv_mesh = pv.PolyData(mesh.vertices, faces)
# adding the base mesh: light blue
p.add_mesh(pv_mesh, color='#abd8ff')

# plotting
cpos = [(785.8704805788776, 708.4540755788776, 741.8613927288776),
 (65.08283250000001, -12.333572500000002, 21.07374465),
 (0.0, 0.0, 1.0)]
p.camera_position = cpos
p.window_size = 2000, 2000
p.show(use_ipyvtk=True)
# p.screenshot("lattice_1")
print(p.camera_position)

2. Voxelize the Mesh

# initialize the base lattice
base_lattice = tg.lattice(mesh.bounds, unit=unit, default_value=1, dtype=int)

# check which voxel centroids is inside the mesh
interior_condition = mesh.contains(base_lattice.centroids)

# reshape the interior condition to the shape of the base_lattice
interior_array = interior_condition.reshape(base_lattice.shape)

# convert the interior array into a lattice
interior_lattice = tg.to_lattice(interior_array, base_lattice.minbound, base_lattice.unit)

# Visualize the voxelization using pyvista plotter

# initiating the plotter
p = pv.Plotter(notebook=True)

# fast visualization of the lattice
interior_lattice.fast_vis(p)

# convert mesh to pv_mesh
faces = np.pad(mesh.faces, ((0, 0),(1,0)), 'constant', constant_values=3)
pv_mesh = pv.PolyData(mesh.vertices, faces)
# adding the base mesh: light blue
p.add_mesh(pv_mesh, color='#abd8ff')

# plotting
cpos = [(785.8704805788776, 708.4540755788776, 741.8613927288776),
 (65.08283250000001, -12.333572500000002, 21.07374465),
 (0.0, 0.0, 1.0)]
p.camera_position = cpos
p.window_size = 2000, 2000
p.show(use_ipyvtk=True)
# p.screenshot("lattice_2_1620")
print(p.camera_position)

# Visualize the voxelization using pyvista plotter

# initiating the plotter
p = pv.Plotter(notebook=True)

# fast visualization of the lattice
interior_lattice.fast_vis(p)

# plotting
cpos = [(785.8704805788776, 708.4540755788776, 741.8613927288776),
 (65.08283250000001, -12.333572500000002, 21.07374465),
 (0.0, 0.0, 1.0)]
p.camera_position = cpos
p.window_size = 2000, 2000
p.show(use_ipyvtk=True)
# p.screenshot("lattice_3_1620")
print(p.camera_position)

3. Saving the lattice to CSV

csv_path = os.path.relpath('../data/lattice972.csv')
interior_lattice.to_csv(csv_path)

Credits

__author__ = "Shervin Azadi"
__license__ = "MIT"
__version__ = "1.0"
__url__ = "https://github.com/shervinazadi/spatial_computing_workshops"
__summary__ = "Spatial Computing Design Studio Workshop on Voxelization"