1. 飞机盘旋
代码
#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>
osg::AnimationPath* createAnimationPath(const osg::Vec3& center,float radius,double looptime)
{
// set up the animation path
osg::AnimationPath* animationPath = new osg::AnimationPath;
animationPath->setLoopMode(osg::AnimationPath::LOOP);
int numSamples = 40;
float yaw = 0.0f;
float yaw_delta = 2.0f*osg::PI/((float)numSamples-1.0f);
float roll = osg::inDegrees(30.0f);
double time=0.0f;
double time_delta = looptime/(double)numSamples;
for(int i=0;i<numSamples;++i)
{
osg::Vec3 position(center+osg::Vec3(sinf(yaw)*radius,cosf(yaw)*radius,0.0f));
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)));
animationPath->insert(time,osg::AnimationPath::ControlPoint(position,rotation));
yaw += yaw_delta;
time += time_delta;
}
return animationPath;
}
osg::Node* createBase(const osg::Vec3& center,float radius)
{
int numTilesX = 10;
int numTilesY = 10;
float width = 2*radius;
float height = 2*radius;
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));
// 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);
}
}
//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
osg::ref_ptr<osg::DrawElementsUShort> whitePrimitives = new osg::DrawElementsUShort(GL_QUADS);
osg::ref_ptr<osg::DrawElementsUShort> blackPrimitives = new osg::DrawElementsUShort(GL_QUADS);
int numIndicesPerRow=numTilesX+1;
for(iy=0;iy<numTilesY;++iy)
{
for(int ix=0;ix<numTilesX;++ix)
{
osg::DrawElementsUShort* primitives = ((iy+ix)%2==0) ? whitePrimitives.get() : blackPrimitives.get();
primitives->push_back(ix +(iy+1)*numIndicesPerRow);
primitives->push_back(ix +iy*numIndicesPerRow);
primitives->push_back((ix+1)+iy*numIndicesPerRow);
primitives->push_back((ix+1)+(iy+1)*numIndicesPerRow);
}
}
// set up a single normal
osg::Vec3Array* normals = new osg::Vec3Array;
normals->push_back(osg::Vec3(0.0f,0.0f,1.0f));
osg::Geometry* geom = new osg::Geometry;
geom->setVertexArray(coords);
geom->setColorArray(colors, osg::Array::BIND_PER_PRIMITIVE_SET);
geom->setNormalArray(normals, osg::Array::BIND_OVERALL);
geom->addPrimitiveSet(whitePrimitives.get());
geom->addPrimitiveSet(blackPrimitives.get());
osg::Geode* geode = new osg::Geode;
geode->addDrawable(geom);
return geode;
}
osg::Node* createMovingModel(const osg::Vec3& center, float radius)
{
float animationLength = 10.0f;
osg::AnimationPath* animationPath = createAnimationPath(center,radius,animationLength);
osg::ref_ptr<osg::Group> model = new osg::Group;
osg::ref_ptr<osg::Node> glider = osgDB::readRefNodeFile("glider.osgt");
if (glider)
{
const osg::BoundingSphere& bs = glider->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(-90.0f),0.0f,0.0f,1.0f));
positioned->addChild(glider);
osg::PositionAttitudeTransform* xform = new osg::PositionAttitudeTransform;
xform->setUpdateCallback(new osg::AnimationPathCallback(animationPath,0.0,1.0));
xform->addChild(positioned);
model->addChild(xform);
}
osg::ref_ptr<osg::Node> cessna = osgDB::readRefNodeFile("cessna.osgt");
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::ref_ptr<osg::MatrixTransform> xform = new osg::MatrixTransform;
xform->setUpdateCallback(new osg::AnimationPathCallback(animationPath,0.0f,2.0));
xform->addChild(positioned);
model->addChild(xform);
}
return model.release();
}
osg::ref_ptr<osg::Group> createModel(bool overlay, osgSim::OverlayNode::OverlayTechnique technique)
{
osg::Vec3 center(0.0f,0.0f,0.0f);
float radius = 100.0f;
osg::ref_ptr<osg::Group> root = new osg::Group;
float baseHeight = center.z()-radius*0.5;
osg::ref_ptr<osg::Node> baseModel = createBase(osg::Vec3(center.x(), center.y(), baseHeight),radius);
osg::ref_ptr<osg::Node> movingModel = createMovingModel(center,radius*0.8f);
if (overlay)
{
osgSim::OverlayNode* overlayNode = new osgSim::OverlayNode(technique);
overlayNode->setContinuousUpdate(true);
overlayNode->setOverlaySubgraph(movingModel);
overlayNode->setOverlayBaseHeight(baseHeight-0.01);
overlayNode->addChild(baseModel);
root->addChild(overlayNode);
}
else
{
root->addChild(baseModel);
}
root->addChild(movingModel);
return root;
}
int main( int argc, char **argv )
{
bool overlay = false;
osg::ArgumentParser arguments(&argc,argv);
while (arguments.read("--overlay")) overlay = true;
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;
// load the nodes from the commandline arguments.
osg::ref_ptr<osg::Group> model = createModel(overlay, technique);
if (!model)
{
return 1;
}
// tilt the scene so the default eye position is looking down on the model.
osg::ref_ptr<osg::MatrixTransform> rootnode = new osg::MatrixTransform;
rootnode->setMatrix(osg::Matrix::rotate(osg::inDegrees(30.0f),1.0f,0.0f,0.0f));
rootnode->addChild(model);
// run optimization over the scene graph
osgUtil::Optimizer optimzer;
optimzer.optimize(rootnode);
// set the scene to render
viewer.setSceneData(rootnode);
viewer.setCameraManipulator(new osgGA::TrackballManipulator());
// viewer.setUpViewOnSingleScreen(1);
#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
}
1-animation.png
