[C++][CGAL]点云转OBJ模型（可导入Unity）-Toy模板网

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一、环境

IDE:VS2017 X64
工具库：Boost 1.7.1 、CGAL5.5.2

简介：通过读取"xyz"格式的点云文件，将点云转换成三维模型。

二、代码

#pragma once
#include <array>
#include <string>
#include <iostream>
#include <fstream>
#include <algorithm>

//CGAL SDK
#include <CGAL/Surface_mesh.h>
#include <CGAL/disable_warnings.h>
#include <CGAL/Projection_traits_xy_3.h>//xy投影面
#include <CGAL/Delaunay_triangulation_2.h>//Delaunay三角剖分
#include <CGAL/Advancing_front_surface_reconstruction.h>
#include <CGAL/Polygon_mesh_processing/compute_normal.h>
#include <CGAL/Polygon_mesh_processing/IO/polygon_mesh_io.h>
#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>// 内核
#include <CGAL/boost/graph/graph_traits_Delaunay_triangulation_2.h>

typedef CGAL::Exact_predicates_inexact_constructions_kernel Kernel;
typedef Kernel::Point_3 Point_3;
typedef Kernel::Vector_3  Vector_3;
typedef std::array<std::size_t, 3> Facet;
typedef CGAL::Surface_mesh<Point_3> Mesh;
typedef boost::graph_traits<Mesh>::vertex_descriptor  vertex_descriptor;


struct Construct
{
	Mesh& mesh;
	template < typename PointIterator>
	Construct(Mesh& mesh, PointIterator b, PointIterator e)
		: mesh(mesh)
	{
		for (; b != e; ++b)
		{
			boost::graph_traits<Mesh>::vertex_descriptor v;
			v = add_vertex(mesh);
			mesh.point(v) = *b;
		}
	}
	Construct& operator=(const Facet f)
	{
		typedef boost::graph_traits<Mesh>::vertex_descriptor vertex_descriptor;
		typedef boost::graph_traits<Mesh>::vertices_size_type size_type;
		mesh.add_face(vertex_descriptor(static_cast<size_type>(f[0])),
			vertex_descriptor(static_cast<size_type>(f[1])),
			vertex_descriptor(static_cast<size_type>(f[2])));
		return *this;
	}
	Construct&
		operator*() { return *this; }
	Construct&
		operator++() { return *this; }
	Construct
		operator++(int) { return *this; }
};


class PointCloud2Mesh
{
public:
	PointCloud2Mesh();
	~PointCloud2Mesh();
public:
	static void CreateMesh(std::string xyzfile, std::string objfile = "mesh.obj");
};

#include "PointCloud2Mesh.h"

PointCloud2Mesh::PointCloud2Mesh()
{
}

PointCloud2Mesh::~PointCloud2Mesh()
{

}

void PointCloud2Mesh::CreateMesh(std::string xyzfile, std::string objfile)
{
	//加载点云数据
	std::string filePath = CGAL::data_file_path(xyzfile);
	std::ifstream in(filePath);
	std::vector<Point_3> points;
	std::copy(std::istream_iterator<Point_3>(in), std::istream_iterator<Point_3>(), std::back_inserter(points));
	in.close();

	//转行Mesh
	Mesh dsm_mesh;
	Construct construct(dsm_mesh, points.begin(), points.end());
	CGAL::advancing_front_surface_reconstruction(points.begin(), points.end(), construct);

	auto vnormals = dsm_mesh.add_property_map<vertex_descriptor, Vector_3>("v:normals", CGAL::NULL_VECTOR).first;

	CGAL::Polygon_mesh_processing::compute_vertex_normals(dsm_mesh, vnormals);

	std::ofstream dsm_ofile(objfile, std::ios_base::binary);
	CGAL::IO::set_binary_mode(dsm_ofile);
	CGAL::IO::write_OBJ(dsm_ofile, dsm_mesh);

	for (vertex_descriptor vd : vertices(dsm_mesh))
	{
		dsm_ofile << "vn " << vnormals[vd].x() << " "
			<< vnormals[vd].y() << " "
			<< vnormals[vd].z() << "\n";
	}
	dsm_ofile.close();
}

三、使用

#include <iostream>
#include "PointCloud2Mesh.h"

using namespace std;


#define PI 3.1415926

#define XYZ "points_3/zongzi.xyz"

void Ball();
void zongzi();

int main(int argc, char** argv)
{
	//
	//Ball();
	zongzi();

	PointCloud2Mesh::CreateMesh(XYZ);
	return EXIT_SUCCESS;
}

void Ball()
{
	float Scale = 10.0f;
	//
	float u = PI * 2;
	float v = PI;

	std::ofstream fout(XYZ, ios::out | ios::app);

	for (int i = 0; i < u *Scale; i++)
	{
		for (int j = 0; j < v*Scale; j++)
		{
			float x = cos(i) * sin(j);
			float y = sin(i) * sin(j);
			float z = cos(j);
			fout << x<<" "<<y<<" "<<z<< std::endl;
		}
	}
	fout.close();
}


void zongzi()
{
	float Scale = 10.0f;
	//
	float u = PI * 2;
	float v = PI;

	std::ofstream fout(XYZ, ios::out | ios::app);

	for (int i = 0; i < u *Scale; i++)
	{
		for (int j = 0; j < v*Scale; j++)
		{
			float x = cos(i);
			float y = cos(j);
			float z = cos(i+j);
			fout << x << " " << y << " " << z << std::endl;
		}
	}
	fout.close();
}

//@2023.6.26
//info:针对破角修改
void zongzi_new()
{
	float Scale = 1.0f;
	//
	float u = PI * 2;
	float v = PI;

	std::ofstream fout(XYZ, ios::out | ios::app);

	for (float i = 0; i <= u *Scale; i += 0.01f)
	{
		for (float j = 0; j <= v*Scale; j += 0.01f)
		{
			float x = cos(i);
			float y = cos(j);
			float z = cos(i+j);
			fout << x << " " << y << " " << z << std::endl;
		}
	}
	fout.close();
}

效果图

点云数据怎么渲染出.obj模型,c++ 文章来源地址https://www.toymoban.com/news/detail-815252.html