Open3D 处理

直接pip install open3d即可

查询已有安装包：pip list

以下分别是从不同角度扫描到的兔子的点云，以bun000为例

import open3d as o3d
import numpy as np

print("Open3D read Point Cloud")
pcd=o3d.io.read_point_cloud(r"bunnydatabun000.ply")
print(pcd)

o3d.visualization.draw_geometries([pcd],width=800,height=600)

 可以看出生成的是一片，不是整个兔子

import open3d as o3d
import numpy as np

print("Open3D read Point Cloud")
pcd=o3d.io.read_point_cloud(r"bunnybunny10k.ply")
print(pcd)

o3d.visualization.draw_geometries([pcd],width=800,height=600)

pcd = o3d.io.read_point_cloud(r"bunnybunny10k.ply")
pcd.paint_uniform_color([0.5, 0.5, 0.5]) #这里的rgb取值为0-1，[0.5, 0.5, 0.5]意味着整个兔子的点云都以灰色呈现

pcd_tree = o3d.geometry.KDTreeFlann(pcd) #KD树贴着物体表面去找近邻的点
pcd.colors[100] = [1, 0, 0] #兔子点云的第100个点以红色呈现（一共6k+个点，不能超过这个范围）

[k, idx, _] = pcd_tree.search_knn_vector_3d(pcd.points[100],100) #对树做近邻搜索，以第一百个点为中心，找附近的一百个点
np.asarray(pcd.colors)[idx[1:], :] = [0, 1, 0] #将返回找到的点的坐标放到一个数组里，色彩设置为绿的

o3d.visualization.draw_geometries([pcd],width=1200,height=1000) #绘制pcd

[k,idx,_] = pcd_tree.search_radius_vector_3d(pcd.points[3000],0.1) #索引半径小于0.02
np.asarray(pcd.colors)[idx[1:], :] = [0, 0, 1]

pcd.colors[2000]=[1, 0, 0]
[k2, idx2, _]=pcd_tree.search_hybrid_vector_3d(pcd.points[2000],0.05,200)
np.asarray(pcd.colors)[idx2[1:], :] = [0, 1, 0.8]
o3d.visualization.draw_geometries([pcd],width=1200,height=1000)

令点与其他临近点生成平面，根据距平面最近距离判断法向量

import open3d as o3d
import numpy as np

print("Open3D read Point Cloud")
pcd = o3d.io.read_point_cloud(r"databunny10k.ply")
print(pcd)
dumppcd = pcd.voxel_down_sample(voxel_size=0.01)  #下采样（降采样）

dumppcd.estimate_normals(search_param=o3d.geometry.KDTreeSearchParamHybrid(radius=0.01,max_nn=30))

print(dumppcd.normals[0])
print(np.asarray(dumppcd.normals)[:10,:])

o3d.visualization.draw_geometries([dumppcd],point_show_normal=True,
                                  window_name="法线估计", width=1200,height=1000,                                mesh_show_back_face=False)

炸毛兔子（×）

需要先计算法向量，判断哪些点应该相连生成平面

print("Open3D read Point Cloud")
pcd = o3d.io.read_triangle_mesh(r"bunny/bunny10k.ply")  #newrabbit.pcd")
print(pcd)
pcd.compute_vertex_normals()
pcdmesh = pcd.sample_points_poisson_disk(3000)
o3d.visualization.draw_geometries([pcdmesh],point_show_normal=True)

radii=[0.005, 0.01, 0.02, 0.04]

ballmesh = o3d.geometry.TriangleMesh.create_from_point_cloud_ball_pivoting(pcdmesh,o3d.utility.DoubleVector(radii))
print(ballmesh)
o3d.visualization.draw_geometries([ballmesh])

o3d.visualization.draw_geometries([pcd, ballmesh])

参考链接：Mesh — Open3D 0.13.0 documentation

mesh = o3d.geometry.TriangleMesh.create_sphere()
mesh.compute_vertex_normals()
o3d.visualization.draw_geometries([mesh])
pcd = mesh.sample_points_uniformly(number_of_points=500)
o3d.visualization.draw_geometries([pcd])