如何利用OpenMesh实现不同格式的3D文件间的转换

可以进行的转化如下

(出处链接见文末参考文档) 

本文示例将文本格式(ASCII)的stl文件转化为二进制格式(Binary)。

目录

step 1 配置openmesh环境

step2 代码实现

step3 设置命令参数

step 4 运行程序得到输出文件

参考文档

---

step 1 配置openmesh环境

可以参考

环境配置 | VS2017配置OpenMesh源码和环境

step2 代码实现

注：debug下跑得同，release下不行，也没搞清原因

#include <iostream>
#include <iterator>
// -------------------- OpenMesh
#include <OpenMesh/Core/IO/MeshIO.hh>
#include <OpenMesh/Core/Mesh/TriMesh_ArrayKernelT.hh>
#include <OpenMesh/Tools/Utils/getopt.h>

// ----------------------------------------------------------------------------

using namespace OpenMesh;

// ----------------------------------------------------------------------------

typedef TriMesh_ArrayKernelT<>  MyMesh;

// ----------------------------------------------------------------------------

#define CHKROPT( Option ) \
  std::cout << "  provides " << #Option \
            << (ropt.check(IO::Options:: Option)?": yes\n":": no\n")

#define CHKWOPT( Option ) \
  std::cout << "  write " << #Option \
            << (wopt.check(IO::Options:: Option)?": yes\n":": no\n")

#define MESHOPT( msg, tf ) \
  std::cout << "  " << msg << ": " << ((tf)?"yes\n":"no\n")

// ----------------------------------------------------------------------------

void parse_commandline(int _argc, char **_argv, MyMesh& _mesh,
	IO::Options &ropt, IO::Options &wopt);

void usage_and_exit(int xcode);

// ----------------------------------------------------------------------------

int main(int argc, char **argv)
{
	MyMesh  mesh;
	IO::Options ropt, wopt;

	// -------------------- evaluate commandline

	parse_commandline(argc, argv, mesh, ropt, wopt);

	// -------------------- read mesh

	if (!IO::read_mesh(mesh, argv[optind], ropt))
	{
		std::cerr << "Error loading mesh from file " << argv[optind] << std::endl;
		return 1;
	}

	// -------------------- show options

	std::cout << "File " << argv[optind] << std::endl;

	std::cout << "  is binary: "
		<< (ropt.check(IO::Options::Binary) ? " yes\n" : " no\n");

	std::cout << "  byte order: ";
	if (ropt.check(IO::Options::Swap))
		std::cout << "swapped\n";
	else if (ropt.check(IO::Options::LSB))
		std::cout << "little endian\n";
	else if (ropt.check(IO::Options::MSB))
		std::cout << "big endian\n";
	else
		std::cout << "don't care\n";

	std::cout << "  provides VertexNormal"
		<< ( // strange layout for doxygen
			ropt.check(IO::Options::VertexNormal)
			? ": yes\n" : ": no\n");
	CHKROPT(VertexColor);
	CHKROPT(VertexTexCoord);
	CHKROPT(FaceNormal);
	CHKROPT(FaceColor);


	// -------------------- mesh stats

	std::cout << "# Vertices: " << mesh.n_vertices() << std::endl;
	std::cout << "# Edges   : " << mesh.n_faces() << std::endl;
	std::cout << "# Faces   : " << mesh.n_faces() << std::endl;


	// -------------------- show write options

	std::cout << "Selected write options:\n";
	std::cout << "  use binary: "
		<< (wopt.check(IO::Options::Binary) ? " yes\n" : " no\n");

	std::cout << "  byte order: ";
	if (wopt.check(IO::Options::Swap))
		std::cout << "swapped\n";
	else if (wopt.check(IO::Options::LSB))
		std::cout << "little endian\n";
	else if (wopt.check(IO::Options::MSB))
		std::cout << "big endian\n";
	else
		std::cout << "don't care\n";

	std::cout << "  write VertexNormal"
		<< (wopt.check(IO::Options::VertexNormal) ? ": yes\n" : ": no\n");
	CHKWOPT(VertexColor);
	CHKWOPT(VertexTexCoord);
	CHKWOPT(FaceNormal);
	CHKWOPT(FaceColor);

	// -------------------- show mesh capabilities

	std::cout << "Mesh supports\n";
	MESHOPT("vertex normals", mesh.has_vertex_normals());
	MESHOPT("vertex colors", mesh.has_vertex_colors());
	MESHOPT("texcoords", mesh.has_vertex_texcoords2D());
	MESHOPT("face normals", mesh.has_face_normals());
	MESHOPT("face colors", mesh.has_face_colors());

	// -------------------- write mesh

	std::cout << "Write mesh to " << argv[optind + 1] << "..";
	if (!IO::write_mesh(mesh, argv[optind + 1], wopt))
	{
		std::cerr << "Error" << std::endl;
		std::cerr << "Possible reasons:\n";
		std::cerr << "1. Chosen format cannot handle an option!\n";
		std::cerr << "2. Mesh does not provide necessary information!\n";
		std::cerr << "3. Or simply cannot open file for writing!\n";
		return 1;
	}
	else
		std::cout << "Ok.\n";

	return 0;
}

// ----------------------------------------------------------------------------

void parse_commandline(int _argc, char **_argv, MyMesh& _mesh,
	IO::Options &ropt, IO::Options &wopt)
{
	int c;
	while ((c = getopt(_argc, _argv, "bhsBF:LMSV:X:")) != -1)
	{
		switch (c)
		{
			// -------------------- read options

			// force binary input
		case 'b':
			ropt += IO::Options::Binary;
			break;

			// force swapping the byte order, when reading a binary file
		case 's':
			ropt += IO::Options::Swap;
			break;

			// -------------------- write options

			// Write binary variant of format if possible
		case 'B':
			wopt += IO::Options::Binary;
			break;

			// 
		case 'F':
			for (size_t i = 0; optarg[i]; ++i)
				switch (optarg[i]) {
				case 'n': wopt += IO::Options::FaceNormal; break;
				case 'c': wopt += IO::Options::FaceColor; break;
				}
			break;

			// Use little endian when writing binary data
		case 'L':
			wopt += IO::Options::LSB;
			break;

			// Use big endian when writing binary data
		case 'M':
			wopt += IO::Options::MSB;
			break;

			// Swap byte order when writing binary data
		case 'S':
			wopt += IO::Options::Swap;
			break;

			//
		case 'V':
		{
			for (size_t i = 0; optarg[i]; ++i)
				switch (optarg[i]) {
				case 'n': // dont't change layout!!
					wopt += IO::Options::VertexNormal;
					break;
				case 't': wopt += IO::Options::VertexTexCoord; break;
				case 'c': wopt += IO::Options::VertexColor; break;
				}
			break;
		}

		// -------------------- request mesh' standard properties
		case 'X':
		{
			char entity = '\0';
			for (size_t i = 0; optarg[i]; ++i)
				switch (optarg[i]) {
				case 'v':
				case 'f': entity = optarg[i]; break;
				case 'n':
					switch (entity) {
					case 'v': _mesh.request_vertex_normals(); break;
					case 'f': _mesh.request_face_normals(); break;
					}
					break;
				case 'c':
					switch (entity) {
					case 'v': _mesh.request_vertex_colors(); break;
					case 'f': _mesh.request_face_colors(); break;
					}
					break;
				case 't':
					switch (entity) {
					case 'v': _mesh.request_vertex_texcoords2D(); break;
					}
					break;
				}
			break;
		}

		// -------------------- help
		case 'h':
			usage_and_exit(0);
		default:
			usage_and_exit(1);
		}
	}

	if (_argc - optind != 2)
		usage_and_exit(1);
}


// ----------------------------------------------------------------------------

void usage_and_exit(int xcode)
{
	std::ostream &os = xcode ? std::cerr : std::cout;

	os << "Usage: io_options [Options] <input> <output>\n"
		<< std::endl;
	os << "  Read and write a mesh, using OpenMesh::IO::Options\n"
		<< std::endl;
	os << "Options:\n"
		<< std::endl;
	os << "a) read options\n"
		<< std::endl
		<< "  -b\n"
		<< "\tAssume input file is a binary file\n"
		<< std::endl
		<< "  -s\n"
		<< "\tSwap byte order when reading a binary file!\n"
		<< std::endl;
	os << "b) write options\n"
		<< std::endl
		<< "  -B\n"
		<< "\tWrite binary data\n"
		<< std::endl
		<< "  -S\n"
		<< "\tSwap byte order, when writing binary data\n"
		<< std::endl
		<< "  -M/-L\n"
		<< "\tUse MSB/LSB byte ordering, when writing binary data\n"
		<< std::endl
		<< "  -V{n|t|c}\n"
		<< "\tWrite vertex normals, texcoords, and/or colors\n"
		<< std::endl
		<< "  -F{n|c}\n"
		<< "\tWrite face normals, and/or colors\n"
		<< std::endl;
	os << "c) Mesh properties\n"
		<< std::endl
		<< "  -Xv{n|c|t}\n"
		<< "\tRequest vertex property normals|colors|texcoords\n"
		<< std::endl
		<< "  -Xf{n|c}\n"
		<< "\tRequest face property normals|colors\n"
		<< std::endl;
	exit(xcode);
}

// end of file
// ============================================================================

step3 设置命令参数

命令参数之间用空格而不是分号隔开

这里我设置了3个参数

-B 表示输出文件为二进制

C:\Kings3D\OFF&STL\little_0.stl 输入文件

C:\Kings3D\OFF&STL\little_0_out.stl 输出文件

step 4 运行程序得到输出文件

用一个可视化程序打开转化后的二进制stl，验证无误

参考文档

OpenMesh: Using IO::Options