#include <osg/Notify> #include <osg/MatrixTransform> #include <osg/PositionAttitudeTransform> #include <osg/Geometry> #include <osg/Geode> #include <osgUtil/Optimizer> #include <osgDB/Registry> #include <osgDB/ReadFile> #include <osgGA/TrackballManipulator> #include <osgGA/FlightManipulator> #include <osgGA/DriveManipulator> #include <osgSim/OverlayNode> #include <osgViewer/Viewer> #include <iostream> // 创建动画路径，参数有中心点，半径，以及循环时间 osg::AnimationPath* createAnimationPath(const osg::Vec3& center,float radius,double looptime) { // 实例化动画路径类 // set up the animation path osg::AnimationPath* animationPath = new osg::AnimationPath; // 设置动画路径的播放模式，当前使用循环模式(SWING LOOP NO_LOOPING )SWING就是在一个区间内顺逆方向循环,LOOP是顺一个方向循环 animationPath->setLoopMode(osg::AnimationPath::LOOP); // 分40个阶段 这个意思就是分为四十个控制点,犹如四十条边的多边形,沿着这个路线飞行 int numSamples = 40; float yaw = 0.0f; // 偏航的分量,这是一个角度分量,算出来每一个多边形的边对应的角度分量2*PI/(n-1) float yaw_delta = 2.0f*osg::PI/((float)numSamples-1.0f); // 旋转角度为30度 float roll = osg::inDegrees(30.0f); // 时间分量 double time=0.0f; //平均的两个控制点之间的时间 double time_delta = looptime/(double)numSamples; // 将时间控制点与位置坐标插入到动画路径中 for(int i=0;i<numSamples;++i) { //这儿是计算出来每个多边形的顶点的坐标,(sinx*r,cosx*r,0.0)是相当于中心点的增量 osg::Vec3 position(center+osg::Vec3(sinf(yaw)*radius,cosf(yaw)*radius,0.0f)); //四元数表示方向,表示在3D空间中的旋转方向**四元数很复杂**这个表示,绕x轴旋转roll,y轴旋转-(yaw+90),z轴0 osg::Quat rotation(osg::Quat(roll,osg::Vec3(0.0,1.0,0.0))*osg::Quat(-(yaw+osg::inDegrees(90.0f)),osg::Vec3(0.0,0.0,1.0))); //和flash动画类似,控制点有位置和转动角度,这样控制点之间是均匀运动 animationPath->insert(time,osg::AnimationPath::ControlPoint(position,rotation)); //递增yaw和time yaw += yaw_delta; time += time_delta; } return animationPath; } // 创建底板，中心点位置在center，半径为radius osg::Node* createBase(const osg::Vec3& center,float radius) { // 一个10x10的底板 int numTilesX = 10; int numTilesY = 10; // 长度与宽度的尺寸 float width = 2*radius; float height = 2*radius; // 计算初始位置与x、y的分量 osg::Vec3 v000(center - osg::Vec3(width*0.5f,height*0.5f,0.0f)); osg::Vec3 dx(osg::Vec3(width/((float)numTilesX),0.0,0.0f)); osg::Vec3 dy(osg::Vec3(0.0f,height/((float)numTilesY),0.0f)); // 计算每个小格子的顶点坐标并压入数组中 // fill in vertices for grid, note numTilesX+1 * numTilesY+1... osg::Vec3Array* coords = new osg::Vec3Array; int iy; for(iy=0;iy<=numTilesY;++iy) { for(int ix=0;ix<=numTilesX;++ix) { coords->push_back(v000+dx*(float)ix+dy*(float)iy); } } // 设置颜色的数组，当前为黑白色两种颜色 //Just two colours - black and white. osg::Vec4Array* colors = new osg::Vec4Array; colors->push_back(osg::Vec4(1.0f,1.0f,1.0f,1.0f)); // white colors->push_back(osg::Vec4(0.0f,0.0f,0.0f,1.0f)); // black int numColors=colors->size(); // 设置绘制四边形的顶点索引与每个四边形的颜色 int numIndicesPerRow=numTilesX+1; osg::UByteArray* coordIndices = new osg::UByteArray; // assumes we are using less than 256 points... osg::UByteArray* colorIndices = new osg::UByteArray; for(iy=0;iy<numTilesY;++iy) { for(int ix=0;ix<numTilesX;++ix) { // four vertices per quad. coordIndices->push_back(ix +(iy+1)*numIndicesPerRow); coordIndices->push_back(ix +iy*numIndicesPerRow); coordIndices->push_back((ix+1)+iy*numIndicesPerRow); coordIndices->push_back((ix+1)+(iy+1)*numIndicesPerRow); // one color per quad colorIndices->push_back((ix+iy)%numColors); } } // 设置法线向量 // set up a single normal osg::Vec3Array* normals = new osg::Vec3Array; normals->push_back(osg::Vec3(0.0f,0.0f,1.0f)); // 设置顶点坐标数组 osg::Geometry* geom = new osg::Geometry; geom->setVertexArray(coords); geom->setVertexIndices(coordIndices); // 设置颜色数组 geom->setColorArray(colors); geom->setColorIndices(colorIndices); geom->setColorBinding(osg::Geometry::BIND_PER_PRIMITIVE); // 设置法线数组 geom->setNormalArray(normals); geom->setNormalBinding(osg::Geometry::BIND_OVERALL); // 需要绘制什么形状的图形，当前为四边形 geom->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS,0,coordIndices->size())); // 将绘制的的图形添加到osg::Geode中 osg::Geode* geode = new osg::Geode; geode->addDrawable(geom); return geode; } // 创建移动的模型，中心点在center，半径为radius osg::Node* createMovingModel(const osg::Vec3& center, float radius) { float animationLength = 10.0f; // 创建动画路径，中心点在center，半径为radius，循环时间为10.0f osg::AnimationPath* animationPath = createAnimationPath(center,radius,animationLength); osg::Group* model = new osg::Group; // 从外部读取一个模型glider.osg作为飞行的模型 osg::Node* glider = osgDB::readNodeFile("glider.osg"); if (glider) { // 根据模型的包围球来计算矩阵 // 平移到原点，缩放模型，然后沿z轴旋转-90度 const osg::BoundingSphere& bs = glider->getBound(); float size = radius/bs.radius()*0.3f; osg::MatrixTransform* positioned = new osg::MatrixTransform; //设置这个值在对象生命周期内为静态的不可改变的数值,或者动态的在对象生命周期内变化的值 positioned->setDataVariance(osg::Object::STATIC); //设置转移矩阵参数 positioned->setMatrix(osg::Matrix::translate(-bs.center())* /*表示平移物体,注意osg的坐标系是z轴是向上的*/ osg::Matrix::scale(size,size,size)* /*x,y,z轴的放缩比例*/ osg::Matrix::rotate(osg::inDegrees(-90.0f),0.0f,0.0f,1.0f)); /*x,y,z轴的旋转角度*/ positioned->addChild(glider); // 设置动画路径的回调函数，使在渲染循环中不停的沿动画路径移动,设置坐标系变换 osg::PositionAttitudeTransform* xform = new osg::PositionAttitudeTransform; xform->setUpdateCallback(new osg::AnimationPathCallback(animationPath,0.0,1.0)); xform->addChild(positioned); model->addChild(xform); } // 从外部读取一个模型cessna.osg // 操作同上，设置动画路径的回调函数，使在渲染的循环中不停的沿动画路径移动 osg::Node* cessna = osgDB::readNodeFile("cessna.osg"); if (cessna) { const osg::BoundingSphere& bs = cessna->getBound(); float size = radius/bs.radius()*0.3f; osg::MatrixTransform* positioned = new osg::MatrixTransform; positioned->setDataVariance(osg::Object::STATIC); positioned->setMatrix(osg::Matrix::translate(-bs.center())* osg::Matrix::scale(size,size,size)* osg::Matrix::rotate(osg::inDegrees(180.0f),0.0f,0.0f,1.0f)); positioned->addChild(cessna); osg::MatrixTransform* xform = new osg::MatrixTransform; xform->setUpdateCallback(new osg::AnimationPathCallback(animationPath,0.0f,2.0)); xform->addChild(positioned); model->addChild(xform); } return model; } // 创建覆盖图，根据覆盖的实现技术来设置 osg::Node* createModel(bool overlay, osgSim::OverlayNode::OverlayTechnique technique) { osg::Vec3 center(0.0f,0.0f,0.0f); float radius = 100.0f; osg::Group* root = new osg::Group; // 创建底板与飞行的模型 float baseHeight = center.z()-radius*0.5; osg::Node* baseModel = createBase(osg::Vec3(center.x(), center.y(), baseHeight),radius); osg::Node* movingModel = createMovingModel(center,radius*0.8f); // 是否设置覆盖图 if (overlay) { // 根据命令行传入的参数来设置 osgSim::OverlayNode* overlayNode = new osgSim::OverlayNode(technique); overlayNode->setContinuousUpdate(true); // 需要设置的覆盖的图的模型为飞行的模型，当前为从外部加载的模型 overlayNode->setOverlaySubgraph(movingModel); // 设置覆盖图距离底板的高度 overlayNode->setOverlayBaseHeight(baseHeight-0.01); overlayNode->addChild(baseModel); // 将覆盖图的节点加入到根节点中 root->addChild(overlayNode); } else { // 不设置覆盖图 root->addChild(baseModel); } root->addChild(movingModel); return root; } int main( int argc, char **argv ) { // 是否使用覆盖模拟 bool overlay = false; // 使用命令行参数实例化osg::ArgumentParset类，方便以后的操作 osg::ArgumentParser arguments(&argc,argv); while (arguments.read("--overlay")) overlay = true; // 获得覆盖节点采用哪种技术实现，提供三种实现技术 osgSim::OverlayNode::OverlayTechnique technique = osgSim::OverlayNode::OBJECT_DEPENDENT_WITH_ORTHOGRAPHIC_OVERLAY; while (arguments.read("--object")) { technique = osgSim::OverlayNode::OBJECT_DEPENDENT_WITH_ORTHOGRAPHIC_OVERLAY; overlay=true; } while (arguments.read("--ortho") || arguments.read("--orthographic")) { technique = osgSim::OverlayNode::VIEW_DEPENDENT_WITH_ORTHOGRAPHIC_OVERLAY; overlay=true; } while (arguments.read("--persp") || arguments.read("--perspective")) { technique = osgSim::OverlayNode::VIEW_DEPENDENT_WITH_PERSPECTIVE_OVERLAY; overlay=true; } // initialize the viewer. osgViewer::Viewer viewer; // 创建底板与飞行的物体,飞行物体通过外部读取 // load the nodes from the commandline arguments. osg::Node* model = createModel(overlay, technique); if (!model) { return 1; } // 创建一个osg::MatrixTransform并设置场景沿x轴旋转30度 // tilt the scene so the default eye position is looking down on the model. osg::MatrixTransform* rootnode = new osg::MatrixTransform; rootnode->setMatrix(osg::Matrix::rotate(osg::inDegrees(30.0f),1.0f,0.0f,0.0f)); rootnode->addChild(model); /// 对整个场景进行优化 // run optimization over the scene graph osgUtil::Optimizer optimzer; optimzer.optimize(rootnode); // 将整个节点设置到场景中进行渲染 // set the scene to render viewer.setSceneData(rootnode); // 设置相机的操作器，当前使用跟踪球的模式进行操作 viewer.setCameraManipulator(new osgGA::TrackballManipulator()); // viewer.setUpViewOnSingleScreen(1); // 提供两中渲染的循环模式 // 第一中采用老式的模式 // 第二中采用封装模式 #if 0 // use of custom simulation time. viewer.realize(); double simulationTime = 0.0; while (!viewer.done()) { viewer.frame(simulationTime); simulationTime += 0.001; } return 0; #else // normal viewer usage. return viewer.run(); #endif }