nbv_rec_control/utils/pts_util.py
2024-10-13 19:47:05 +08:00

279 lines
10 KiB
Python

import numpy as np
import open3d as o3d
import torch
import trimesh
from scipy.spatial import cKDTree
from utils.pose_util import PoseUtil
class PtsUtil:
@staticmethod
def voxel_downsample_point_cloud(point_cloud, voxel_size=0.005):
o3d_pc = o3d.geometry.PointCloud()
o3d_pc.points = o3d.utility.Vector3dVector(point_cloud)
downsampled_pc = o3d_pc.voxel_down_sample(voxel_size)
return np.asarray(downsampled_pc.points)
@staticmethod
def random_downsample_point_cloud(point_cloud, num_points, require_idx=False):
if point_cloud.shape[0] == 0:
if require_idx:
return point_cloud, np.array([])
return point_cloud
idx = np.random.choice(len(point_cloud), num_points, replace=True)
if require_idx:
return point_cloud[idx], idx
return point_cloud[idx]
@staticmethod
def fps_downsample_point_cloud(point_cloud, num_points, require_idx=False):
N = point_cloud.shape[0]
mask = np.zeros(N, dtype=bool)
sampled_indices = np.zeros(num_points, dtype=int)
sampled_indices[0] = np.random.randint(0, N)
distances = np.linalg.norm(
point_cloud - point_cloud[sampled_indices[0]], axis=1
)
for i in range(1, num_points):
farthest_index = np.argmax(distances)
sampled_indices[i] = farthest_index
mask[farthest_index] = True
new_distances = np.linalg.norm(
point_cloud - point_cloud[farthest_index], axis=1
)
distances = np.minimum(distances, new_distances)
sampled_points = point_cloud[sampled_indices]
if require_idx:
return sampled_points, sampled_indices
return sampled_points
@staticmethod
def random_downsample_point_cloud_tensor(point_cloud, num_points):
idx = torch.randint(0, len(point_cloud), (num_points,))
return point_cloud[idx]
@staticmethod
def voxelize_points(points, voxel_size):
voxel_indices = np.floor(points / voxel_size).astype(np.int32)
unique_voxels = np.unique(voxel_indices, axis=0, return_inverse=True)
return unique_voxels
@staticmethod
def transform_point_cloud(points, pose_mat):
points_h = np.concatenate([points, np.ones((points.shape[0], 1))], axis=1)
points_h = np.dot(pose_mat, points_h.T).T
return points_h[:, :3]
@staticmethod
def get_overlapping_points(
point_cloud_L, point_cloud_R, voxel_size=0.005, require_idx=False
):
voxels_L, indices_L = PtsUtil.voxelize_points(point_cloud_L, voxel_size)
voxels_R, _ = PtsUtil.voxelize_points(point_cloud_R, voxel_size)
voxel_indices_L = voxels_L.view([("", voxels_L.dtype)] * 3)
voxel_indices_R = voxels_R.view([("", voxels_R.dtype)] * 3)
overlapping_voxels = np.intersect1d(voxel_indices_L, voxel_indices_R)
mask_L = np.isin(
indices_L, np.where(np.isin(voxel_indices_L, overlapping_voxels))[0]
)
overlapping_points = point_cloud_L[mask_L]
if require_idx:
return overlapping_points, mask_L
return overlapping_points
@staticmethod
def filter_points(
points,
points_normals,
cam_pose,
voxel_size=0.002,
theta=45,
z_range=(0.25, 0.5),
):
"""filter with z range"""
points_cam = PtsUtil.transform_point_cloud(points, np.linalg.inv(cam_pose))
idx = (points_cam[:, 2] > z_range[0]) & (points_cam[:, 2] < z_range[1])
z_filtered_points = points[idx]
""" filter with normal """
sampled_points = PtsUtil.voxel_downsample_point_cloud(
z_filtered_points, voxel_size
)
kdtree = cKDTree(points_normals[:, :3])
_, indices = kdtree.query(sampled_points)
nearest_points = points_normals[indices]
normals = nearest_points[:, 3:]
camera_axis = -cam_pose[:3, 2]
normals_normalized = normals / np.linalg.norm(normals, axis=1, keepdims=True)
cos_theta = np.dot(normals_normalized, camera_axis)
theta_rad = np.deg2rad(theta)
idx = cos_theta > np.cos(theta_rad)
filtered_sampled_points = sampled_points[idx]
return filtered_sampled_points[:, :3]
@staticmethod
def multi_scale_icp(
source, target, voxel_size_range, init_transformation=None, steps=20
):
pipreg = o3d.pipelines.registration
if init_transformation is not None:
current_transformation = init_transformation
else:
current_transformation = np.identity(4)
cnt = 0
best_score = 1e10
best_reg = None
voxel_sizes = []
for i in range(steps):
voxel_sizes.append(
voxel_size_range[0]
+ i * (voxel_size_range[1] - voxel_size_range[0]) / steps
)
for voxel_size in voxel_sizes:
radius_normal = voxel_size * 2
source_downsampled = source.voxel_down_sample(voxel_size)
source_downsampled.estimate_normals(
search_param=o3d.geometry.KDTreeSearchParamHybrid(
radius=radius_normal, max_nn=30
)
)
target_downsampled = target.voxel_down_sample(voxel_size)
target_downsampled.estimate_normals(
search_param=o3d.geometry.KDTreeSearchParamHybrid(
radius=radius_normal, max_nn=30
)
)
reg_icp = pipreg.registration_icp(
source_downsampled,
target_downsampled,
voxel_size * 2,
current_transformation,
pipreg.TransformationEstimationPointToPlane(),
pipreg.ICPConvergenceCriteria(max_iteration=500),
)
cnt += 1
if reg_icp.fitness == 0:
score = 1e10
else:
score = reg_icp.inlier_rmse / reg_icp.fitness
if score < best_score:
best_score = score
best_reg = reg_icp
return best_reg, best_score
@staticmethod
def multi_scale_ransac(source_downsampled, target_downsampled, source_fpfh, model_fpfh, voxel_size_range, steps=20):
pipreg = o3d.pipelines.registration
cnt = 0
best_score = 1e10
best_reg = None
voxel_sizes = []
for i in range(steps):
voxel_sizes.append(
voxel_size_range[0]
+ i * (voxel_size_range[1] - voxel_size_range[0]) / steps
)
for voxel_size in voxel_sizes:
reg_ransac = pipreg.registration_ransac_based_on_feature_matching(
source_downsampled,
target_downsampled,
source_fpfh,
model_fpfh,
mutual_filter=True,
max_correspondence_distance=voxel_size*2,
estimation_method=pipreg.TransformationEstimationPointToPoint(False),
ransac_n=4,
checkers=[pipreg.CorrespondenceCheckerBasedOnEdgeLength(0.9)],
criteria=pipreg.RANSACConvergenceCriteria(8000000, 500),
)
cnt += 1
if reg_ransac.fitness == 0:
score = 1e10
else:
score = reg_ransac.inlier_rmse / reg_ransac.fitness
if score < best_score:
best_score = score
best_reg = reg_ransac
return best_reg, best_score
@staticmethod
def register(pcl: np.ndarray, model: trimesh.Trimesh, voxel_size=0.01):
radius_normal = voxel_size * 2
pipreg = o3d.pipelines.registration
model_pcd = o3d.geometry.PointCloud()
model_pcd.points = o3d.utility.Vector3dVector(model.vertices)
model_downsampled = model_pcd.voxel_down_sample(voxel_size)
model_downsampled.estimate_normals(
search_param=o3d.geometry.KDTreeSearchParamHybrid(
radius=radius_normal, max_nn=30
)
)
model_fpfh = pipreg.compute_fpfh_feature(
model_downsampled,
o3d.geometry.KDTreeSearchParamHybrid(radius=radius_normal, max_nn=100),
)
source_pcd = o3d.geometry.PointCloud()
source_pcd.points = o3d.utility.Vector3dVector(pcl)
source_downsampled = source_pcd.voxel_down_sample(voxel_size)
source_downsampled.estimate_normals(
search_param=o3d.geometry.KDTreeSearchParamHybrid(
radius=radius_normal, max_nn=30
)
)
source_fpfh = pipreg.compute_fpfh_feature(
source_downsampled,
o3d.geometry.KDTreeSearchParamHybrid(radius=radius_normal, max_nn=100),
)
reg_ransac, ransac_best_score = PtsUtil.multi_scale_ransac(
source_downsampled,
model_downsampled,
source_fpfh,
model_fpfh,
voxel_size_range=(0.03, 0.005),
steps=3,
)
reg_icp, icp_best_score = PtsUtil.multi_scale_icp(
source_downsampled,
model_downsampled,
voxel_size_range=(0.02, 0.001),
init_transformation=reg_ransac.transformation,
steps=50,
)
return reg_icp.transformation
@staticmethod
def get_pts_from_depth(depth, cam_intrinsic, cam_extrinsic):
h, w = depth.shape
i, j = np.meshgrid(np.arange(w), np.arange(h), indexing="xy")
z = depth
x = (i - cam_intrinsic[0, 2]) * z / cam_intrinsic[0, 0]
y = (j - cam_intrinsic[1, 2]) * z / cam_intrinsic[1, 1]
points_camera = np.stack((x, y, z), axis=-1).reshape(-1, 3)
mask = mask.reshape(-1, 4)
points_camera = np.concatenate(
[points_camera, np.ones((points_camera.shape[0], 1))], axis=-1
)
points_world = np.dot(cam_extrinsic, points_camera.T).T[:, :3]
data = {
"points_world": points_world,
"points_camera": points_camera,
}
return data