101 lines
4.2 KiB
Python
101 lines
4.2 KiB
Python
import numpy as np
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import open3d as o3d
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import torch
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from scipy.spatial import cKDTree
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class PtsUtil:
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@staticmethod
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def voxel_downsample_point_cloud(point_cloud, voxel_size=0.005):
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o3d_pc = o3d.geometry.PointCloud()
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o3d_pc.points = o3d.utility.Vector3dVector(point_cloud)
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downsampled_pc = o3d_pc.voxel_down_sample(voxel_size)
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return np.asarray(downsampled_pc.points)
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@staticmethod
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def random_downsample_point_cloud(point_cloud, num_points, require_idx=False):
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if point_cloud.shape[0] == 0:
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if require_idx:
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return point_cloud, np.array([])
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return point_cloud
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idx = np.random.choice(len(point_cloud), num_points, replace=True)
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if require_idx:
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return point_cloud[idx], idx
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return point_cloud[idx]
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@staticmethod
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def fps_downsample_point_cloud(point_cloud, num_points, require_idx=False):
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N = point_cloud.shape[0]
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mask = np.zeros(N, dtype=bool)
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sampled_indices = np.zeros(num_points, dtype=int)
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sampled_indices[0] = np.random.randint(0, N)
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distances = np.linalg.norm(point_cloud - point_cloud[sampled_indices[0]], axis=1)
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for i in range(1, num_points):
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farthest_index = np.argmax(distances)
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sampled_indices[i] = farthest_index
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mask[farthest_index] = True
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new_distances = np.linalg.norm(point_cloud - point_cloud[farthest_index], axis=1)
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distances = np.minimum(distances, new_distances)
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sampled_points = point_cloud[sampled_indices]
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if require_idx:
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return sampled_points, sampled_indices
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return sampled_points
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@staticmethod
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def random_downsample_point_cloud_tensor(point_cloud, num_points):
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idx = torch.randint(0, len(point_cloud), (num_points,))
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return point_cloud[idx]
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@staticmethod
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def voxelize_points(points, voxel_size):
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voxel_indices = np.floor(points / voxel_size).astype(np.int32)
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unique_voxels = np.unique(voxel_indices, axis=0, return_inverse=True)
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return unique_voxels
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@staticmethod
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def transform_point_cloud(points, pose_mat):
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points_h = np.concatenate([points, np.ones((points.shape[0], 1))], axis=1)
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points_h = np.dot(pose_mat, points_h.T).T
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return points_h[:, :3]
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@staticmethod
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def get_overlapping_points(point_cloud_L, point_cloud_R, voxel_size=0.005, require_idx=False):
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voxels_L, indices_L = PtsUtil.voxelize_points(point_cloud_L, voxel_size)
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voxels_R, _ = PtsUtil.voxelize_points(point_cloud_R, voxel_size)
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voxel_indices_L = voxels_L.view([("", voxels_L.dtype)] * 3)
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voxel_indices_R = voxels_R.view([("", voxels_R.dtype)] * 3)
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overlapping_voxels = np.intersect1d(voxel_indices_L, voxel_indices_R)
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mask_L = np.isin(
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indices_L, np.where(np.isin(voxel_indices_L, overlapping_voxels))[0]
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)
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overlapping_points = point_cloud_L[mask_L]
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if require_idx:
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return overlapping_points, mask_L
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return overlapping_points
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@staticmethod
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def filter_points(points, points_normals, cam_pose, voxel_size=0.002, theta=45, z_range=(0.2, 0.45)):
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""" filter with z range """
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points_cam = PtsUtil.transform_point_cloud(points, np.linalg.inv(cam_pose))
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idx = (points_cam[:, 2] > z_range[0]) & (points_cam[:, 2] < z_range[1])
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z_filtered_points = points[idx]
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""" filter with normal """
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sampled_points = PtsUtil.voxel_downsample_point_cloud(z_filtered_points, voxel_size)
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kdtree = cKDTree(points_normals[:,:3])
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_, indices = kdtree.query(sampled_points)
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nearest_points = points_normals[indices]
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normals = nearest_points[:, 3:]
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camera_axis = -cam_pose[:3, 2]
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normals_normalized = normals / np.linalg.norm(normals, axis=1, keepdims=True)
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cos_theta = np.dot(normals_normalized, camera_axis)
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theta_rad = np.deg2rad(theta)
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idx = cos_theta > np.cos(theta_rad)
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filtered_sampled_points= sampled_points[idx]
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return filtered_sampled_points[:, :3] |