若该文为原创文章，未经允许不得转载
原博主博客地址：https://blog.csdn.net/qq21497936
原博主博客导航：https://blog.csdn.net/qq21497936/article/details/102478062
本文章博客地址：https://blog.csdn.net/qq21497936/article/details/105372492
各位读者，知识无穷而人力有穷，要么改需求，要么找专业人士，要么自己研究
红胖子(红模仿)的博文大全：开发技术集合（包含Qt实用技术、树莓派、三维、OpenCV、OpenGL、ffmpeg、OSG、单片机、软硬结合等等）持续更新中...（点击传送门）
Qt开发专栏：项目实战（点击传送门）
OSG开发专栏（点击传送门）
需求
使用Qt开发内嵌的三维地理学科工具。
原理
使用Qt+Osg三维研发，依托Qt内嵌OSG。
相关博客
《OSG三维开发专栏》：循序渐进学习OSG
《OSG开发笔记（一）：OSG介绍、编译》：OSG介绍与编译
《OSG开发笔记（四）：OSG不使用osgQt重写类嵌入Qt应用程序》：OSG源码嵌入Qt
《OSG开发笔记（十）：OSG模型的变换之平移、旋转和缩放》：对于模型结点的基本操作
《OSG开发笔记（十四）：OSG交互》：按键消息和鼠标消息的交互
《OSG开发笔记（十五）：OSG光照》：光影的学习，产生立体感
《OSG开发笔记（十八）：OSG鼠标拾取pick、拽托球体以及多光源》：pick拾取三维物体交互
《OSG开发笔记（二十一）：OSG使用HUD绘制图形以及纹理混合模式》：hud绘制背景和前景
《OSG开发笔记（二十三）：Qt使用QOpenGLWidget渲染OSG和地球仪》：基础版本的地球仪开发关键
（以上是支撑该需求的三维技术博客）
Demo v3.1.0
相比于v2.0.0版本：修复了星球纹理贴图存在缝隙的问题；修复了缩放无限制的bug；对球体、贴图、2d/3d切换、缩放、旋转增加了序列化接口(demo为启动应用后恢复之前关闭的状态)。
下载地址
Demo v3.1.0运行包下载地址：https://download.csdn.net/download/qq21497936/12542665
QQ群：1047134658（点击“文件”搜索“教育学科工具”，群内与博文同步更新）
Demo v2.0.0
相比于v1.0.0版本，增加了地球以外的八大行星，对布局进行了调整，适配了多种分辨率，并且优化了部分代码；
下载地址
Demo v2.0.0运行包下载地址：https://download.csdn.net/download/qq21497936/12312105
QQ群：1047134658（点击“文件”搜索“教育学科工具”，群内与博文同步更新所有可开源的源码模板）
Demo v1.0.0
完成地理星球中地球的研发，包括基本操作、鼠标pick旋转、缩放等，包含海洋分布、人口分布、气候分布、海平线等等功能；
下载地址
Demo v1.0.0运行包下载地址：https://download.csdn.net/download/qq21497936/11489564
QQ群：1047134658（点击“文件”搜索“教育学科工具”，群内与博文同步更新所有可开源的源码模板）
关键代码
获取背景Hud结点（传入文件）
osg::ref_ptr<osg::Node> OsgStarWidget::getBackgroundNode(QString imageFile)
{
osg::ref_ptr<osg::Group> pGroup = new osg::Group();
osg::ref_ptr<osg::Camera> pCamera = 0;
osg::ref_ptr<osg::Geode> pGeode = 0;
// 创建背景相机
{
// 步骤一：创建相机
pCamera = new osg::Camera();
// 步骤二：设置矩阵 显示得界面边坐标 左 右 下 上
pCamera->setProjectionMatrixAsOrtho2D(0, 1920, 0, 1080);
// 步骤三：设置视图矩阵
pCamera->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
// 步骤四：不受父类矩阵影响
pCamera->setViewMatrix(osg::Matrix::identity());
// 步骤五：清除深度缓存
pCamera->setClearMask(GL_DEPTH_BUFFER_BIT);
// 步骤六：设置为不接受事件，让其得不到焦点
pCamera->setAllowEventFocus(false);
// 步骤七：设置渲染顺序
pCamera->setRenderOrder(osg::Camera::NESTED_RENDER); // 显示为背景HUD
// 步骤八：关闭光照，通过osg::StateSet设置
pGeode = new osg::Geode();
osg::ref_ptr<osg::StateSet> pStateSet = pGeode->getOrCreateStateSet();
pStateSet->setMode(GL_LIGHTING, osg::StateAttribute::OFF);
// 步骤九：关闭深度测试
pStateSet->setMode(GL_DEPTH_TEST, osg::StateAttribute::OFF);
}
// 创建背景图形图片
{
// 步骤一：创建几何信息体
osg::ref_ptr<osg::Geometry> pGeometry = new osg::Geometry;
// 步骤二：绑定顶点
osg::ref_ptr<osg::Vec3Array> pVec3Array = new osg::Vec3Array;
pGeometry->setVertexArray(pVec3Array.get());
// 步骤三：设置顶点(屏幕坐标)
pVec3Array->push_back(osg::Vec3( 0, 0, 0));
pVec3Array->push_back(osg::Vec3(1920, 0, 0));
pVec3Array->push_back(osg::Vec3(1920, 1080, 0));
pVec3Array->push_back(osg::Vec3( 0, 1080, 0));
// 步骤四：读取图片(纹理图片)
osg::ref_ptr<osg::Image> pImage = new osg::Image;
pImage = osgDB::readImageFile(imageFile.toStdString());
if(!pImage || !pImage->valid())
{
LOG_WARN(QString("Failed to load image file: %1").arg(imageFile));
return 0;
}
// 步骤五：创建纹理
osg::ref_ptr<osg::Texture2D> pTexture2D = new osg::Texture2D;
pTexture2D->setImage(pImage);
pTexture2D->setUnRefImageDataAfterApply(true);
// 步骤六：绑定纹理坐标
osg::ref_ptr<osg::Vec2Array> pVec2Array = new osg::Vec2Array;
pGeometry->setTexCoordArray(0, pVec2Array.get());
// 步骤七：设置纹理坐标
pVec2Array->push_back(osg::Vec2(0.0, 0.0));
pVec2Array->push_back(osg::Vec2(1.0, 0.0));
pVec2Array->push_back(osg::Vec2(1.0, 1.0));
pVec2Array->push_back(osg::Vec2(0.0, 1.0));
// 步骤八：关联纹理状态
osg::ref_ptr<osg::StateSet> pStateSet = pGeometry->getOrCreateStateSet();
pStateSet->setTextureAttributeAndModes(0, pTexture2D.get(), osg::StateAttribute::ON);
// 步骤九：绑定法线
osg::ref_ptr<osg::Vec3Array> pVec3ArrayNormal = new osg::Vec3Array;
pGeometry->setNormalArray(pVec3ArrayNormal.get());
// 步骤十：设置法线方式
pGeometry->setNormalBinding(osg::Geometry::BIND_OVERALL);
// 步骤十一：设置法线方向
pVec3ArrayNormal->push_back(osg::Vec3f(0.0, 1.0, 0.0));
// 步骤十二：绘制四个顶点的图形
pGeometry->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS, 0, 4));
// 步骤十三：将图形添加进几何节点
pGeode->addDrawable(pGeometry.get());
}
pCamera->addChild(pGeode);
pGroup->addChild(pCamera);
return pGroup;
}
更换地球纹理
void OsgStarWidget::change3DImage(QString imageFile)
{
// 步骤一：读取图片(纹理图片)
osg::ref_ptr<osg::Image> pImage = 0;
pImage = osgDB::readImageFile(imageFile.toStdString());
if(!pImage || !pImage->valid())
{
LOG_WARN(QString("Failed to load image file: %1").arg(imageFile));
return;
}
// 步骤二：创建纹理
osg::ref_ptr<osg::Texture2D> pTexture2D = new osg::Texture2D;
pTexture2D->setImage(pImage);
pTexture2D->setUnRefImageDataAfterApply(true);
// 步骤三：球体体渲染纹理
osg::ref_ptr<osg::StateSet> pStateSet = _pGeode->getOrCreateStateSet();
pStateSet->setTextureAttribute(0, pTexture2D.get());
pStateSet->setTextureMode(0, GL_TEXTURE_2D, osg::StateAttribute::ON);
_pGeode->setStateSet(pStateSet);
}拾取pick、缩放
MyUserPickEventHandler.h
#ifndef MYUSERPICKEVENTHANDLER_H
#define MYUSERPICKEVENTHANDLER_H
#include <osg/Node>
#include <osgViewer/Viewer>
class MyUserPickEventHandler : public osgGA::GUIEventHandler
{
public:
MyUserPickEventHandler();
public:
osg::ref_ptr<osg::MatrixTransform> getMatrixTransform() const;
void setMatrixTransform(const osg::ref_ptr<osg::MatrixTransform> &pMatrixTransform);
float getRadius() const;
void setRadius(float radius);
float getMinScale() const;
void setMinScale(float minScale);
float getMaxScale() const;
void setMaxScale(float maxScale);
float getZoomInStep() const;
void setZoomInStep(float zoomInStep);
float getZoomOutStep() const;
void setZoomOutStep(float zoomOutStep);
public:
/** Handle event. Override the handle(..) method in your event handlers to respond to events. */
// virtual bool handle(osgGA::Event* event, osg::Object* pObject, osg::NodeVisitor* pNodeVisitor);
/** Handle events, return true if handled, false otherwise. */
// virtual bool handle(const osgGA::GUIEventAdapter& guiEventAdapter, osgGA::GUIActionAdapter& guiActionAdapter, osg::Object* pObject, osg::NodeVisitor* pNodeVisitor);
/** Deprecated, Handle events, return true if handled, false otherwise. */
virtual bool handle(const osgGA::GUIEventAdapter& guiEventAdapter, osgGA::GUIActionAdapter& guiActionAdapter);
protected:
bool pick(const double x, const double y, osgViewer::Viewer *pViewer, osg::Vec3dArray *pVec3dArrayOut);
bool pick(const double x, const double y, osgViewer::Viewer *pViewer, osg::Node *pNode, osg::Vec3dArray *pVec3dArrayOut);
osg::Vec3d screen2Word(osg::Vec3d screenVec3d, osgViewer::Viewer *pViewer);
private:
bool _pickEarth;
osg::Vec3d _originVec3d;
osg::Vec3d _lastVec3d;
float _radius;
float _maxScale;
float _minScale;
float _zoomInStep;
float _zoomOutStep;
osg::ref_ptr<osg::MatrixTransform> _pMatrixTransform;
};
#endif // MYUSEREVENTHANDLER_H
MyUserPickEventHandler.cpp
#include "MyUserPickEventHandler.h"
#include "define.h"
#include "osg/MatrixTransform"
#include <QtMath>
#include "MyMath.h"
MyUserPickEventHandler::MyUserPickEventHandler()
: osgGA::GUIEventHandler(),
_pickEarth(false)
{
}
osg::ref_ptr<osg::MatrixTransform> MyUserPickEventHandler::getMatrixTransform() const
{
return _pMatrixTransform;
}
void MyUserPickEventHandler::setMatrixTransform(const osg::ref_ptr<osg::MatrixTransform> &pMatrixTransform)
{
_pMatrixTransform = pMatrixTransform;
}
float MyUserPickEventHandler::getRadius() const
{
return _radius;
}
void MyUserPickEventHandler::setRadius(float radius)
{
_radius = radius;
}
float MyUserPickEventHandler::getMaxScale() const
{
return _maxScale;
}
void MyUserPickEventHandler::setMaxScale(float maxScale)
{
_maxScale = maxScale;
}
float MyUserPickEventHandler::getMinScale() const
{
return _minScale;
}
void MyUserPickEventHandler::setMinScale(float minScale)
{
_minScale = minScale;
}
float MyUserPickEventHandler::getZoomInStep() const
{
return _zoomInStep;
}
void MyUserPickEventHandler::setZoomInStep(float zoomInStep)
{
_zoomInStep = zoomInStep;
}
//bool MyUserEventHandler::handle(osgGA::Event *event, osg::Object *object, osg::NodeVisitor *pNodeVisitor)
//{
// LOG_DEBUG("");
// return false;
//}
//bool MyUserEventHandler::handle(const osgGA::GUIEventAdapter &guiEventAdapter, osgGA::GUIActionAdapter &guiActionAdapter, osg::Object *pObject, osg::NodeVisitor *pNodeVisitor)
//{
// LOG_DEBUG("");
// return true;
//}
bool MyUserPickEventHandler::handle(const osgGA::GUIEventAdapter
&guiEventAdapter, osgGA::GUIActionAdapter &guiActionAdapter)
{
switch (guiEventAdapter.getEventType())
{
case osgGA::GUIEventAdapter::EventType::SCROLL:
case osgGA::GUIEventAdapter::EventType::PUSH:
case osgGA::GUIEventAdapter::EventType::RELEASE:
case osgGA::GUIEventAdapter::EventType::DRAG:
break;
default:
return true;
break;
}
bool flag = false;
if(_pMatrixTransform.get() == 0)
{
LOG_INFO("Fialed to handle, because it's not set the node of transform!!!");
return true;
}
// 使用智能指针就挂，原因未知
// osg::ref_ptr<osgViewer::Viewer> pViewer = dynamic_cast<osgViewer::Viewer*>(&guiActionAdapter);
osgViewer::Viewer *pViewer = dynamic_cast<osgViewer::Viewer*>(&guiActionAdapter);
if(pViewer == 0)
{
LOG_WARN("Fialed to get viewer!");
return true;
}
osg::Matrix matrix = _pMatrixTransform->getMatrix();
osg::Vec3d vec3d;
osg::ref_ptr<osg::Vec3dArray> pVec3dArray = new osg::Vec3dArray();
qreal offsetAngle;
float nowRadius = qSqrt(_pMatrixTransform->getBound().radius2() / 3.0);
switch (guiEventAdapter.getEventType())
{
case osgGA::GUIEventAdapter::EventType::SCROLL:
switch (guiEventAdapter.getScrollingMotion())
{
case osgGA::GUIEventAdapter::SCROLL_UP: // 鼠标滚轮向上放大
if(nowRadius / _radius >= _maxScale)
{
break;
}
matrix *= osg::Matrix::scale(_zoomInStep, _zoomInStep, _zoomInStep);
_pMatrixTransform->setMatrix(matrix);
flag = true;
break;
case osgGA::GUIEventAdapter::SCROLL_DOWN: // 鼠标滚轮向下缩小
if(nowRadius / _radius <= _minScale)
{
break;
}
matrix *= osg::Matrix::scale(_zoomOutStep, _zoomOutStep, _zoomOutStep);
_pMatrixTransform->setMatrix(matrix);
flag = true;
break;
default:
break;
}
break;
case osgGA::GUIEventAdapter::EventType::PUSH:
switch (guiEventAdapter.getButton())
{
case osgGA::GUIEventAdapter::LEFT_MOUSE_BUTTON:
if(pick(guiEventAdapter.getX(), guiEventAdapter.getY(), pViewer, _pMatrixTransform, pVec3dArray.get()))
{
// 拾取到物体
_pickEarth = true;
_lastVec3d = pVec3dArray->at(0);
}else{
_pickEarth = false;
}
break;
default:
break;
}
break;
case osgGA::GUIEventAdapter::EventType::DRAG:
if(pick(guiEventAdapter.getX(), guiEventAdapter.getY(), pViewer, _pMatrixTransform, pVec3dArray.get()))
{
if(_pickEarth == false)
{
// 拾取到物体
_pickEarth = true;
_lastVec3d = pVec3dArray->at(0);
break;
}
// 相交点
vec3d = pVec3dArray->at(0);
// 计算x轴方向角度
offsetAngle = MyMath::lineAngleRakeRatio(QPoint(0,0), QPointF(vec3d.y(), vec3d.z()))
-MyMath::lineAngleRakeRatio(QPoint(0,0), QPointF(_lastVec3d.y(), _lastVec3d.z()));
matrix *= osg::Matrix::rotate(osg::DegreesToRadians(-offsetAngle), 1, 0, 0);
// 计算z轴方向角度
offsetAngle = MyMath::lineAngleRakeRatio(QPoint(0,0), QPointF(vec3d.y(), vec3d.x()))
-MyMath::lineAngleRakeRatio(QPoint(0,0), QPointF(_lastVec3d.y(), _lastVec3d.x()));
matrix *= osg::Matrix::rotate(osg::DegreesToRadians(offsetAngle), 0, 0, 1);
_pMatrixTransform->setMatrix(matrix);
_lastVec3d = vec3d;
}else{
_pickEarth = false;
}
break;
case osgGA::GUIEventAdapter::EventType::RELEASE:
_pickEarth = false;
break;
default:
break;
}
return true;
}
bool MyUserPickEventHandler::pick(const double x, const double y, osgViewer::Viewer *pViewer, osg::Vec3dArray *pVec3dArrayOut)
{
bool ret = false;
// 判断场景
if(!pViewer->getSceneData())
{
return false;
}
// 判断是否拾取到物体
osgUtil::LineSegmentIntersector::Intersections intersections;
if(pViewer->computeIntersections(x, y, intersections))
{
for(auto iter = intersections.begin();
iter != intersections.end();
iter++)
{
pVec3dArrayOut->push_back(iter->getWorldIntersectPoint());
ret = true;
}
}
return ret;
}
bool MyUserPickEventHandler::pick(const double x, const double y, osgViewer::Viewer *pViewer, osg::Node *pNode, osg::Vec3dArray *pVec3dArrayOut)
{
bool ret = false;
// 判断场景
if(!pViewer->getSceneData())
{
return false;
}
// 判断是否拾取到物体
osgUtil::LineSegmentIntersector::Intersections intersections;
if(pViewer->computeIntersections(x, y, intersections))
{
for(auto iter = intersections.begin();
iter != intersections.end();
iter++)
{
for(int index = 0; index < iter->nodePath.size(); index++)
{
if(iter->nodePath.at(index)->asNode() == pNode)
{
pVec3dArrayOut->push_back(iter->getWorldIntersectPoint());
ret = true;
break;
}
}
break;
}
}
return ret;
}
osg::Vec3d MyUserPickEventHandler::screen2Word(osg::Vec3d screenVec3d, osgViewer::Viewer *pViewer)
{
osg::ref_ptr<osg::Camera> pCamera = pViewer->getCamera();
osg::Matrix matrix = pCamera->getViewMatrix() *
pCamera->getProjectionMatrix() *
pCamera->getViewport()->computeWindowMatrix();
osg::Matrix intertMatrix = osg::Matrix::inverse(matrix);
osg::Vec3d worldVec3d = screenVec3d * intertMatrix;
return worldVec3d;
}
float MyUserPickEventHandler::getZoomOutStep() const
{
return _zoomOutStep;
}
void MyUserPickEventHandler::setZoomOutStep(float zoomOutStep)
{
_zoomOutStep = zoomOutStep;
}
原博主博客地址：https://blog.csdn.net/qq21497936
原博主博客导航：https://blog.csdn.net/qq21497936/article/details/102478062
本文章博客地址：https://blog.csdn.net/qq21497936/article/details/105372492