OSG 读取OSGB倾斜数据

OSGB数据是一个四叉树结构，本文测试使用OSG加载OSGB倾斜摄影测量数据。

示例数据

在这里插入图片描述

Code

1、遍历所有osgb数据文件生成空间索引
2、通过建立的空间索引加载数据

#include <iostream>
#include <string>
#include <filesystem>#include <osgViewer/Viewer>
#include <osgDB/ReadFile>
#include <osgDB/WriteFile>using namespace std;static void findDir(const string& dir, vector<string>& subDirs)
{//subDirs.clear();for (auto& i : filesystem::directory_iterator(dir)) {if (i.path().string() == "." || i.path().string() == "..")continue;if (i.is_directory()) {subDirs.push_back(i.path().string());}}
}static std::string DirOrPathGetName(std::string filePath)
{size_t m = filePath.find_last_of('\\');if (m == string::npos){return filePath;}size_t p = filePath.find_last_of('.');if (p != string::npos && p > m)		{filePath.erase(p);}std::string dirPath = filePath;dirPath.erase(0, m + 1);return dirPath;
}void createObliqueIndexes(std::string fileDir)
{string dataDir = fileDir + "/Data";osg::ref_ptr<osg::Group> group = new osg::Group();vector<string> subDirs;findDir(dataDir, subDirs);for (size_t i = 0; i < subDirs.size(); i++){string name = DirOrPathGetName(subDirs[i]);string path = subDirs[i] + "/" + name + ".osgb";if (!filesystem::exists(path))continue;osg::ref_ptr<osg::Node> node = osgDB::readNodeFile(path);osg::ref_ptr<osg::PagedLOD> lod = new osg::PagedLOD();if (!node.valid())continue;//auto bs=node->computeBound();auto bs = node->getBound();auto c = bs.center();auto r = bs.radius();lod->setCenter(c);lod->setRadius(r);lod->setRangeMode(osg::LOD::RangeMode::PIXEL_SIZE_ON_SCREEN);osg::ref_ptr<osg::Geode> geode = new osg::Geode;geode->getOrCreateStateSet();lod->addChild(geode.get());std::string relativeFilePath = "./Data/" + name + "/" + name + ".osgb";lod->setFileName(0, "");lod->setFileName(1, relativeFilePath);lod->setRange(0, 0, 1.0);																							//第一层不可见lod->setRange(1, 1.0, FLT_MAX);lod->setDatabasePath("");group->addChild(lod);}std::string outputLodFile = fileDir + "/Data.osgb";osgDB::writeNodeFile(*group, outputLodFile);
}int main(int argc, char *argv[])
{if (argc < 2)return -1;if (!filesystem::exists(argv[1]))return -1;std::string fileDir = argv[1];std::string outputLodFile = fileDir + "/Data.osgb";createObliqueIndexes(fileDir);osgViewer::Viewer viewer;osg::Node * node = new osg::Node;node = osgDB::readNodeFile(outputLodFile);viewer.setSceneData(node);viewer.setUpViewInWindow(50, 50, 800, 600);return viewer.run();
}

构建

添加 C++17支持。

cmake_minimum_required(VERSION 3.15)
project(osgDemo)set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED YES)
set(CMAKE_CXX_EXTENSIONS NO)find_package(OpenSceneGraph REQUIRED osgDB osgViewer)
include_directories(${OPENSCENEGRAPH_INCLUDE_DIR})
add_executable (osgDemo "main.cpp")
target_link_libraries(${PROJECT_NAME} ${OPENSCENEGRAPH_LIBRARIES})