PointCloudVolume/crop-demo-1.py

import json
import numpy as np
import open3d as o3d

CUBOID_EXTENT_METERS = 200

METERS_BELOW_START = 5
METERS_ABOVE_START = 30

def main():
  ## Point Cloud
  points = np.array([
    ## These points lie inside the cuboid
    [-2770.94365061042, 722.0595600050154, -20.004812609192445],
    [-2755.94365061042, 710.0595600050154, -20.004812609192445],
    [-2755.94365061042, 710.0595600050154, -15.004812609192445],

    ## These points lie outside the cuboid
    [-2755.94365061042 + CUBOID_EXTENT_METERS, 710.0595600050154, -15.004812609192445],
    [-2755.94365061042, 710.0595600050154 + CUBOID_EXTENT_METERS, -15.004812609192445],
  ]).reshape([-1, 3])

  point_cloud = o3d.geometry.PointCloud()
  point_cloud.points = o3d.utility.Vector3dVector(points)

  ## Start point here corresponds to an ego vehicle position start in a point cloud
  start_position = {'x': -2755.94365061042, 'y': 722.0595600050154, 'z': -20.004812609192445}
  cuboid_points = getCuboidPoints(start_position)

  points = o3d.utility.Vector3dVector(cuboid_points)
  oriented_bounding_box = o3d.geometry.OrientedBoundingBox.create_from_points(points)
  point_cloud_crop = point_cloud.crop(oriented_bounding_box)

  # View original point cloud with the cuboid, all 5 points present
  o3d.visualization.draw_geometries([point_cloud, oriented_bounding_box])

  # View cropped point cloud with the cuboid, only 3 points present
  o3d.visualization.draw_geometries([point_cloud_crop, oriented_bounding_box])

def getCuboidPoints(start_position):
  return np.array([
    # Vertices Polygon1
    [start_position['x'] + (CUBOID_EXTENT_METERS / 2), start_position['y'] + (CUBOID_EXTENT_METERS / 2), start_position['z'] + METERS_ABOVE_START], # face-topright
    [start_position['x'] - (CUBOID_EXTENT_METERS / 2), start_position['y'] + (CUBOID_EXTENT_METERS / 2), start_position['z'] + METERS_ABOVE_START], # face-topleft
    [start_position['x'] - (CUBOID_EXTENT_METERS / 2), start_position['y'] - (CUBOID_EXTENT_METERS / 2), start_position['z'] + METERS_ABOVE_START], # rear-topleft
    [start_position['x'] + (CUBOID_EXTENT_METERS / 2), start_position['y'] - (CUBOID_EXTENT_METERS / 2), start_position['z'] + METERS_ABOVE_START], # rear-topright

    # Vertices Polygon 2
    [start_position['x'] + (CUBOID_EXTENT_METERS / 2), start_position['y'] + (CUBOID_EXTENT_METERS / 2), start_position['z'] - METERS_BELOW_START],
    [start_position['x'] - (CUBOID_EXTENT_METERS / 2), start_position['y'] + (CUBOID_EXTENT_METERS / 2), start_position['z'] - METERS_BELOW_START],
    [start_position['x'] - (CUBOID_EXTENT_METERS / 2), start_position['y'] - (CUBOID_EXTENT_METERS / 2), start_position['z'] - METERS_BELOW_START],
    [start_position['x'] + (CUBOID_EXTENT_METERS / 2), start_position['y'] - (CUBOID_EXTENT_METERS / 2), start_position['z'] - METERS_BELOW_START],
  ]).astype("float64") 

if __name__ == '__main__':
  main()