点云文件常用格式转换（pcd,txt,ply,obj,stl）

pcd转txt

#include 
#include 
#include    

int main(int argc, char *argv[])
{
	pcl::PointCloud<pcl::PointXYZ>::Ptr cloud(new pcl::PointCloud<pcl::PointXYZ>);
	pcl::io::loadPCDFile("rabbit.pcd", *cloud);

	std::ofstream outfile;
	outfile.open("rabbit.txt");

	for (size_t i = 0; i < cloud->points.size(); ++i)
	{
		outfile << cloud->points[i].x << "\t" << cloud->points[i].y << "\t" << cloud->points[i].z << "\n";
	}

	return 0;
}

txt转pcd

#include 
#include 
#include    

int main(int argc, char *argv[])
{
	std::ifstream infile;
	infile.open("rabbit.txt");
	
	float x, y, z;
	pcl::PointCloud<pcl::PointXYZ>::Ptr cloud(new pcl::PointCloud<pcl::PointXYZ>);
	while (infile >> x >> y >> z)
	{
		cloud->push_back(pcl::PointXYZ(x, y, z));
	}
	pcl::io::savePCDFileBinary("rabbit.pcd", *cloud);

	return 0;
}

pcd转ply

#include           
#include   
#include  
#include   

int main(int argc, char** argv)
{
	pcl::PointCloud<pcl::PointXYZ>::Ptr cloud(new pcl::PointCloud<pcl::PointXYZ>);
	pcl::io::loadPCDFile("rabbit.pcd", *cloud);
	pcl::io::savePLYFileBinary("rabbit.ply", *cloud);

	return 0;
}

pcd转ply(三角网格化）

#include 
#include 
#include 
#include   
#include 
#include 
#include 

using namespace std;

int main(int argc, char** argv)
{
	// Load input file
	pcl::PointCloud<pcl::PointXYZ>::Ptr cloud(new pcl::PointCloud<pcl::PointXYZ>);
	pcl::io::loadPCDFile("rabbit.pcd", *cloud);

	// Normal estimation*
	pcl::NormalEstimation<pcl::PointXYZ, pcl::Normal> n;
	pcl::PointCloud<pcl::Normal>::Ptr normals(new pcl::PointCloud<pcl::Normal>);
	pcl::search::KdTree<pcl::PointXYZ>::Ptr tree(new pcl::search::KdTree<pcl::PointXYZ>);
	tree->setInputCloud(cloud);
	n.setInputCloud(cloud);
	n.setSearchMethod(tree);
	n.setKSearch(10);
	n.compute(*normals);
	//* normals should not contain the point normals + surface curvatures

	// Concatenate the XYZ and normal fields*
	pcl::PointCloud<pcl::PointNormal>::Ptr cloud_with_normals(new pcl::PointCloud<pcl::PointNormal>);
	pcl::concatenateFields(*cloud, *normals, *cloud_with_normals);
	//* cloud_with_normals = cloud + normals

	// Create search tree*
	pcl::search::KdTree<pcl::PointNormal>::Ptr tree2(new pcl::search::KdTree<pcl::PointNormal>);
	tree2->setInputCloud(cloud_with_normals);

	// Initialize objects
	pcl::GreedyProjectionTriangulation<pcl::PointNormal> gp3;
	pcl::PolygonMesh triangles;

	// Set the maximum distance between connected points (maximum edge length)
	gp3.setSearchRadius(1);

	// Set typical values for the parameters
	gp3.setMu(2.5);
	gp3.setMaximumNearestNeighbors(100);
	gp3.setMaximumSurfaceAngle(M_PI / 4); // 45 degrees
	gp3.setMinimumAngle(M_PI / 18); // 10 degrees
	gp3.setMaximumAngle(2 * M_PI / 3); // 120 degrees
	gp3.setNormalConsistency(false);

	// Get result
	gp3.setInputCloud(cloud_with_normals);
	gp3.setSearchMethod(tree2);
	gp3.reconstruct(triangles);
	pcl::io::savePLYFile("rabbit.ply", triangles);
	return 0;
}

ply转pcd

#include           
#include   
#include  
#include   

int main(int argc, char** argv)
{
	pcl::PointCloud<pcl::PointXYZ>::Ptr cloud(new pcl::PointCloud<pcl::PointXYZ>);
	pcl::io::loadPLYFile("rabbit.ply", *cloud);
	pcl::io::savePCDFileBinary("rabbit.pcd", *cloud);

	return 0;
}

obj/ply转pcd（均匀采样）

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 


VTK_MODULE_INIT(vtkRenderingOpenGL2)
VTK_MODULE_INIT(vtkInteractionStyle)


inline double uniform_deviate(int seed)
{
	double ran = seed * (1.0 / (RAND_MAX + 1.0));
	return ran;
}

inline void randomPointTriangle(float a1, float a2, float a3, float b1, float b2, float b3, float c1, float c2, float c3, Eigen::Vector4f& p)
{
	float r1 = static_cast<float> (uniform_deviate(rand()));
	float r2 = static_cast<float> (uniform_deviate(rand()));
	float r1sqr = std::sqrt(r1);
	float OneMinR1Sqr = (1 - r1sqr);
	float OneMinR2 = (1 - r2);
	a1 *= OneMinR1Sqr;
	a2 *= OneMinR1Sqr;
	a3 *= OneMinR1Sqr;
	b1 *= OneMinR2;
	b2 *= OneMinR2;
	b3 *= OneMinR2;
	c1 = r1sqr * (r2 * c1 + b1) + a1;
	c2 = r1sqr * (r2 * c2 + b2) + a2;
	c3 = r1sqr * (r2 * c3 + b3) + a3;
	p[0] = c1;
	p[1] = c2;
	p[2] = c3;
	p[3] = 0;
}

inline void randPSurface(vtkPolyData * polydata, std::vector<double> * cumulativeAreas, double totalArea, Eigen::Vector4f& p, bool calcNormal, Eigen::Vector3f& n)
{
	float r = static_cast<float> (uniform_deviate(rand()) * totalArea);

	std::vector<double>::iterator low = std::lower_bound(cumulativeAreas->begin(), cumulativeAreas->end(), r);
	vtkIdType el = vtkIdType(low - cumulativeAreas->begin());

	double A[3], B[3], C[3];
	vtkIdType npts = 0;
	vtkIdType *ptIds = NULL;
	polydata->GetCellPoints(el, npts, ptIds);
	polydata->GetPoint(ptIds[0], A);
	polydata->GetPoint(ptIds[1], B);
	polydata->GetPoint(ptIds[2], C);
	if (calcNormal)
	{
		// OBJ: Vertices are stored in a counter-clockwise order by default
		Eigen::Vector3f v1 = Eigen::Vector3f(A[0], A[1], A[2]) - Eigen::Vector3f(C[0], C[1], C[2]);
		Eigen::Vector3f v2 = Eigen::Vector3f(B[0], B[1], B[2]) - Eigen::Vector3f(C[0], C[1], C[2]);
		n = v1.cross(v2);
		n.normalize();
	}
	randomPointTriangle(float(A[0]), float(A[1]), float(A[2]),
		float(B[0]), float(B[1]), float(B[2]),
		float(C[0]), float(C[1]), float(C[2]), p);
}

void uniform_sampling(vtkSmartPointer<vtkPolyData> polydata, size_t n_samples, bool calc_normal, pcl::PointCloud<pcl::PointNormal> & cloud_out)
{
	polydata->BuildCells();
	vtkSmartPointer<vtkCellArray> cells = polydata->GetPolys();

	double p1[3], p2[3], p3[3], totalArea = 0;
	std::vector<double> cumulativeAreas(cells->GetNumberOfCells(), 0);
	size_t i = 0;
	vtkIdType npts = 0, *ptIds = NULL;
	for (cells->InitTraversal(); cells->GetNextCell(npts, ptIds); i++)
	{
		polydata->GetPoint(ptIds[0], p1);
		polydata->GetPoint(ptIds[1], p2);
		polydata->GetPoint(ptIds[2], p3);
		totalArea += vtkTriangle::TriangleArea(p1, p2, p3);
		cumulativeAreas[i] = totalArea;
	}

	cloud_out.points.resize(n_samples);
	cloud_out.width = static_cast<pcl::uint32_t> (n_samples);
	cloud_out.height = 1;

	for (i = 0; i < n_samples; i++)
	{
		Eigen::Vector4f p;
		Eigen::Vector3f n;
		randPSurface(polydata, &cumulativeAreas, totalArea, p, calc_normal, n);
		cloud_out.points[i].x = p[0];
		cloud_out.points[i].y = p[1];
		cloud_out.points[i].z = p[2];
		if (calc_normal)
		{
			cloud_out.points[i].normal_x = n[0];
			cloud_out.points[i].normal_y = n[1];
			cloud_out.points[i].normal_z = n[2];
		}
	}
}

using namespace pcl;
using namespace pcl::io;
using namespace pcl::console;

const int default_number_samples = 1000000;
const float default_leaf_size = 1.0f;

void printHelp(int, char **argv)
{
	print_error("Syntax is: %s input.{ply,obj} output.pcd \n", argv[0]);
	print_info("  where options are:\n");
	print_info("                     -n_samples X      = number of samples (default: ");
	print_value("%d", default_number_samples);
	print_info(")\n");
	print_info(
		"                     -leaf_size X  = the XYZ leaf size for the VoxelGrid -- for data reduction (default: ");
	print_value("%f", default_leaf_size);
	print_info(" m)\n");
	print_info("                     -write_normals = flag to write normals to the output pcd\n");
	print_info(
		"                     -no_vis_result = flag to stop visualizing the generated pcd\n");
}

/* ---[ */
int main(int argc, char **argv)
{
	print_info("Convert a CAD model to a point cloud using uniform sampling. For more information, use: %s -h\n", argv[0]);

	if (argc < 3)
	{
		printHelp(argc, argv);
		return (-1);
	}

	// Parse command line arguments
	int SAMPLE_POINTS_ = default_number_samples;
	parse_argument(argc, argv, "-n_samples", SAMPLE_POINTS_);
	float leaf_size = default_leaf_size;
	parse_argument(argc, argv, "-leaf_size", leaf_size);
	bool vis_result = !find_switch(argc, argv, "-no_vis_result");
	const bool write_normals = find_switch(argc, argv, "-write_normals");

	// Parse the command line arguments for .ply and PCD files
	std::vector<int> pcd_file_indices = parse_file_extension_argument(argc, argv, ".pcd");
	if (pcd_file_indices.size() != 1)
	{
		print_error("Need a single output PCD file to continue.\n");
		return (-1);
	}
	std::vector<int> ply_file_indices = parse_file_extension_argument(argc, argv, ".ply");
	std::vector<int> obj_file_indices = parse_file_extension_argument(argc, argv, ".obj");
	if (ply_file_indices.size() != 1 && obj_file_indices.size() != 1)
	{
		print_error("Need a single input PLY/OBJ file to continue.\n");
		return (-1);
	}

	vtkSmartPointer<vtkPolyData> polydata1 = vtkSmartPointer<vtkPolyData>::New();
	if (ply_file_indices.size() == 1)
	{
		pcl::PolygonMesh mesh;
		pcl::io::loadPolygonFilePLY(argv[ply_file_indices[0]], mesh);
		pcl::io::mesh2vtk(mesh, polydata1);
	}
	else if (obj_file_indices.size() == 1)
	{
		vtkSmartPointer<vtkOBJReader> readerQuery = vtkSmartPointer<vtkOBJReader>::New();
		readerQuery->SetFileName(argv[obj_file_indices[0]]);
		readerQuery->Update();
		polydata1 = readerQuery->GetOutput();
	}

	//make sure that the polygons are triangles!
	vtkSmartPointer<vtkTriangleFilter> triangleFilter = vtkSmartPointer<vtkTriangleFilter>::New();
#if VTK_MAJOR_VERSION < 6
	triangleFilter->SetInput(polydata1);
#else
	triangleFilter->SetInputData(polydata1);
#endif
	triangleFilter->Update();

	vtkSmartPointer<vtkPolyDataMapper> triangleMapper = vtkSmartPointer<vtkPolyDataMapper>::New();
	triangleMapper->SetInputConnection(triangleFilter->GetOutputPort());
	triangleMapper->Update();
	polydata1 = triangleMapper->GetInput();

	bool INTER_VIS = false;

	if (INTER_VIS)
	{
		visualization::PCLVisualizer vis;
		vis.addModelFromPolyData(polydata1, "mesh1", 0);
		vis.setRepresentationToSurfaceForAllActors();
		vis.spin();
	}

	pcl::PointCloud<pcl::PointNormal>::Ptr cloud_1(new pcl::PointCloud<pcl::PointNormal>);
	uniform_sampling(polydata1, SAMPLE_POINTS_, write_normals, *cloud_1);

	if (INTER_VIS)
	{
		visualization::PCLVisualizer vis_sampled;
		vis_sampled.addPointCloud<pcl::PointNormal>(cloud_1);
		if (write_normals)
			vis_sampled.addPointCloudNormals<pcl::PointNormal>(cloud_1, 1, 0.02f, "cloud_normals");
		vis_sampled.spin();
	}

	// Voxelgrid
	VoxelGrid<PointNormal> grid_;
	grid_.setInputCloud(cloud_1);
	grid_.setLeafSize(leaf_size, leaf_size, leaf_size);

	pcl::PointCloud<pcl::PointNormal>::Ptr voxel_cloud(new pcl::PointCloud<pcl::PointNormal>);
	grid_.filter(*voxel_cloud);


	if (!write_normals)
	{
		pcl::PointCloud<pcl::PointXYZ>::Ptr cloud_xyz(new pcl::PointCloud<pcl::PointXYZ>);
		// Strip uninitialized normals from cloud:
		pcl::copyPointCloud(*voxel_cloud, *cloud_xyz);
		savePCDFileBinary(argv[pcd_file_indices[0]], *cloud_xyz);
	}
	else
	{
		savePCDFileBinary(argv[pcd_file_indices[0]], *voxel_cloud);
	}
}

pcd转obj

#include 
#include 
#include 
#include 
#include 

int main(int argc, char** argv)
{
	pcl::PointCloud<pcl::PointXYZ>::Ptr cloud(new pcl::PointCloud<pcl::PointXYZ>);
	pcl::io::loadPCDFile("rabbit.pcd", *cloud);
	pcl::PolygonMesh mesh;
	pcl::toPCLPointCloud2(*cloud, mesh.cloud);
	pcl::io::saveOBJFile("rabbit.obj", mesh);

	return 0;
}

stl转ply

#include 
#include 
#include 
#include 
#include 

using namespace std;

struct Coordinate {
	float x, y, z;
	bool operator<(const Coordinate& rhs) {
		return x<rhs.x || (x == rhs.x&&y<rhs.y) || (x == rhs.x&&y == rhs.y&&z<rhs.z);
	}
	bool operator==(const Coordinate& rhs) {
		return x == rhs.x&&y == rhs.y && z == rhs.z;
	}
};
vector<Coordinate> vecSorted, vecOrigin;
vector<Coordinate>::iterator iter, iterBegin;

int numberOfFacets;
int numberOfPoints;
int index;


char c1[] = "ply\nformat binary_little_endian 1.0\ncomment By ET \nelement vertex ";
char c2[] = "\nproperty float x\nproperty float y\nproperty float z\nelement face ";
char c3[] = "\nproperty list uchar int vertex_indices\nend_header\n";

int main(int argc, char **argv)
{
	cout << ".exe .STL .ply" << endl;
	clock_t start, finish;
	double totaltime;
	start = clock();

	int length;
	int position = 80;
	fstream fileIn(argv[1], ios::in | ios::binary);
	fileIn.seekg(0, ios::end);
	length = (int)fileIn.tellg();
	fileIn.seekg(0, ios::beg);
	char* buffer = new char[length];
	fileIn.read(buffer, length);
	fileIn.close();


	numberOfFacets = *(int*)&(buffer[position]);
	position += 4;
	cout << "Number of Facets: " << numberOfFacets << endl;
	for (int i = 0; i < numberOfFacets; i++)
	{
		Coordinate tmpC;
		position += 12;
		for (int j = 0; j < 3; j++)
		{
			tmpC.x = *(float*)&(buffer[position]);
			position += 4;
			tmpC.y = *(float*)&(buffer[position]);
			position += 4;
			tmpC.z = *(float*)&(buffer[position]);
			position += 4;
			vecOrigin.push_back(tmpC);
		}
		position += 2;
	}

	free(buffer);

	vecSorted = vecOrigin;
	sort(vecSorted.begin(), vecSorted.end());
	iter = unique(vecSorted.begin(), vecSorted.end());
	vecSorted.erase(iter, vecSorted.end());
	numberOfPoints = vecSorted.size();

	ofstream fileOut(argv[2], ios::binary | ios::out | ios::trunc);

	fileOut.write(c1, sizeof(c1) - 1);
	fileOut << numberOfPoints;
	fileOut.write(c2, sizeof(c2) - 1);
	fileOut << numberOfFacets;
	fileOut.write(c3, sizeof(c3) - 1);


	buffer = new char[numberOfPoints * 3 * 4];
	position = 0;
	for (int i = 0; i < numberOfPoints; i++)
	{
		buffer[position++] = *(char*)(&vecSorted[i].x);
		buffer[position++] = *((char*)(&vecSorted[i].x) + 1);
		buffer[position++] = *((char*)(&vecSorted[i].x) + 2);
		buffer[position++] = *((char*)(&vecSorted[i].x) + 3);
		buffer[position++] = *(char*)(&vecSorted[i].y);
		buffer[position++] = *((char*)(&vecSorted[i].y) + 1);
		buffer[position++] = *((char*)(&vecSorted[i].y) + 2);
		buffer[position++] = *((char*)(&vecSorted[i].y) + 3);
		buffer[position++] = *(char*)(&vecSorted[i].z);
		buffer[position++] = *((char*)(&vecSorted[i].z) + 1);
		buffer[position++] = *((char*)(&vecSorted[i].z) + 2);
		buffer[position++] = *((char*)(&vecSorted[i].z) + 3);
	}


	fileOut.write(buffer, numberOfPoints * 3 * 4);

	free(buffer);

	buffer = new char[numberOfFacets * 13];

	for (int i = 0; i < numberOfFacets; i++)
	{
		buffer[13 * i] = (unsigned char)3;
	}

	iterBegin = vecSorted.begin();
	position = 0;
	for (int i = 0; i < numberOfFacets; i++)
	{
		position++;
		for (int j = 0; j < 3; j++)
		{
			iter = lower_bound(vecSorted.begin(), vecSorted.end(), vecOrigin[3 * i + j]);
			index = iter - iterBegin;
			buffer[position++] = *(char*)(&index);
			buffer[position++] = *((char*)(&index) + 1);
			buffer[position++] = *((char*)(&index) + 2);
			buffer[position++] = *((char*)(&index) + 3);

		}
	}

	fileOut.write(buffer, numberOfFacets * 13);

	free(buffer);
	fileOut.close();

	finish = clock();
	totaltime = (double)(finish - start) / CLOCKS_PER_SEC * 1000;
	cout << "All Time: " << totaltime << "ms\n";

	return 0;
}

ply转stl

#include 
#include 
#include 

int main(int argc, char** argv)
{
	vtkSmartPointer<vtkPLYReader> reader = vtkSmartPointer<vtkPLYReader>::New();
	reader->SetFileName("rabbit.ply");
	reader->Update();

	vtkSmartPointer<vtkPolyData> polyData = vtkSmartPointer<vtkPolyData>::New();
	polyData = reader->GetOutput();
	polyData->GetNumberOfPoints();

	vtkSmartPointer<vtkSTLWriter> writer = vtkSmartPointer<vtkSTLWriter>::New();
	writer->SetInputData(polyData);
	writer->SetFileName("rabbit.stl");
	writer->Write();

	return 0;
}