54 lines
1.4 KiB
Python
54 lines
1.4 KiB
Python
import open3d as o3d
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import numpy as np
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def compute_curvature_open3d(pcd, radius=0.1, max_nn=30):
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"""
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使用 Open3D 计算曲率
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Args:
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pcd: Open3D 点云对象
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radius: 搜索半径
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max_nn: 最大邻居数
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Returns:
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curvature: 曲率数组
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"""
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# 估计法线
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pcd.estimate_normals(
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search_param=o3d.geometry.KDTreeSearchParamHybrid(radius=radius, max_nn=max_nn)
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)
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# 计算曲率（Open3D 在估计法线时已计算）
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# 曲率值存储在 pcd.point.normals 的第三个分量？
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# 实际上 Open3D 需要单独计算
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# 方法：使用 PCA 重新计算
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points = np.asarray(pcd.points)
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n_points = len(points)
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curvature = np.zeros(n_points)
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tree = o3d.geometry.KDTreeFlann(pcd)
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for i in range(n_points):
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[k, idx, _] = tree.search_radius_vector_3d(pcd.points[i], radius)
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if k < 3:
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curvature[i] = 1.0
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continue
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neighbors = points[idx]
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centroid = np.mean(neighbors, axis=0)
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centered = neighbors - centroid
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cov = np.cov(centered.T)
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eigenvalues = np.linalg.eigvalsh(cov)
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eigenvalues = np.sort(eigenvalues)
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curvature[i] = eigenvalues[0] / (eigenvalues.sum() + 1e-8)
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return curvature
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# 使用示例
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pcd = o3d.io.read_point_cloud("pointcloud.pcd")
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curvature = compute_curvature_open3d(pcd, radius=0.05) |