#!/usr/bin/env python3
# -*- coding: utf-8 -*-
__author__ = "Christian"
__doc__ = r"""
Created on 29/03/2020
"""
import numpy
from matplotlib import pyplot
from .plot3d import plot_voxelgrid
__all__ = ["VoxelGrid"]
[docs]class VoxelGrid(object):
"""description"""
[docs] def __init__(self, points, x_y_z=(1, 1, 1), bb_cuboid=True, build=True):
"""
Parameters
----------
points: (N,3) ndarray
The point cloud from wich we want to construct the VoxelGrid.
Where N is the number of points in the point cloud and the second
dimension represents the x, y and z coordinates of each point.
x_y_z: list
The segments in wich each axis will be divided.
x_y_z[0]: x axis
x_y_z[1]: y axis
x_y_z[2]: z axis
bb_cuboid(Optional): bool
If True(Default):
The bounding box of the point cloud will be adjusted
in order to have all the dimensions of equal lenght.
If False:
The bounding box is allowed to have dimensions of different sizes.
"""
self.points = points
xyz_min = numpy.min(points, axis=0) - 0.001
xyz_max = numpy.max(points, axis=0) + 0.001
if bb_cuboid:
#: adjust to obtain a minimum bounding box with all sides of equal lenght
diff = max(xyz_max - xyz_min) - (xyz_max - xyz_min)
xyz_min = xyz_min - diff / 2
xyz_max = xyz_max + diff / 2
self.xyz_min = xyz_min
self.xyz_max = xyz_max
segments = []
shape = []
for i in range(3):
# note the +1 in num
if type(x_y_z[i]) is not int:
raise TypeError(f"x_y_z[{i}] must be int")
s, step = numpy.linspace(
xyz_min[i], xyz_max[i], num=(x_y_z[i] + 1), retstep=True
)
segments.append(s)
shape.append(step)
self.segments = segments
self.shape = shape
self.n_voxels = x_y_z[0] * x_y_z[1] * x_y_z[2]
self.n_x = x_y_z[0]
self.n_y = x_y_z[1]
self.n_z = x_y_z[2]
self.id = f"{x_y_z[0]},{x_y_z[1]},{x_y_z[2]}-{bb_cuboid}"
if build:
self.build()
[docs] def build(self):
"""description"""
structure = numpy.zeros((len(self.points), 4), dtype=int)
structure[:, 0] = numpy.searchsorted(self.segments[0], self.points[:, 0]) - 1
structure[:, 1] = numpy.searchsorted(self.segments[1], self.points[:, 1]) - 1
structure[:, 2] = numpy.searchsorted(self.segments[2], self.points[:, 2]) - 1
# i = ((y * n_x) + x) + (z * (n_x * n_y))
structure[:, 3] = ((structure[:, 1] * self.n_x) + structure[:, 0]) + (
structure[:, 2] * (self.n_x * self.n_y)
)
self.structure = structure
vector = numpy.zeros(self.n_voxels)
count = numpy.bincount(self.structure[:, 3])
vector[: len(count)] = count
self.vector = vector.reshape(self.n_z, self.n_y, self.n_x)
[docs] def plot(self, d=2, cmap="Oranges", show_axis: bool = False):
"""
Args:
d:
cmap:
axis:
Returns:
:param show_axis:
:type show_axis:
"""
if d == 2:
fig, axes = pyplot.subplots(
int(numpy.ceil(self.n_z / 4)), 4, figsize=(8, 8)
)
pyplot.tight_layout()
for i, ax in enumerate(axes.flat):
if i >= len(self.vector):
break
im = ax.imshow(self.vector[i], cmap=cmap, interpolation="none")
ax.set_title("Level " + str(i))
fig.subplots_adjust(right=0.8)
cbar_ax = fig.add_axes([0.85, 0.15, 0.05, 0.7])
cbar = fig.colorbar(im, cax=cbar_ax)
cbar.set_label("NUMBER OF POINTS IN VOXEL")
elif d == 3:
return plot_voxelgrid(self, cmap=cmap, show_axis=show_axis)
