OpenSceneGraph/examples/osgprerender/osgprerender.cpp

353 lines
12 KiB
C++

#include <osg/GLExtensions>
#include <osg/Node>
#include <osg/Geometry>
#include <osg/Notify>
#include <osg/MatrixTransform>
#include <osg/Texture2D>
#include <osg/Stencil>
#include <osg/ColorMask>
#include <osg/Depth>
#include <osg/Billboard>
#include <osg/Material>
#include <osgGA/TrackballManipulator>
#include <osgGA/FlightManipulator>
#include <osgGA/DriveManipulator>
#include <osgUtil/TransformCallback>
#include <osgUtil/SmoothingVisitor>
#include <osgDB/Registry>
#include <osgDB/ReadFile>
#include <osgProducer/Viewer>
// call back which cretes a deformation field to oscilate the model.
class MyGeometryCallback :
public osg::Drawable::UpdateCallback,
public osg::Drawable::AttributeFunctor
{
public:
MyGeometryCallback(const osg::Vec3& o,
const osg::Vec3& x,const osg::Vec3& y,const osg::Vec3& z,
double period,double xphase,double amplitude):
_firstCall(true),
_startTime(0.0),
_time(0.0),
_period(period),
_xphase(xphase),
_amplitude(amplitude),
_origin(o),
_xAxis(x),
_yAxis(y),
_zAxis(z) {}
virtual void update(osg::NodeVisitor* nv,osg::Drawable* drawable)
{
const osg::FrameStamp* fs = nv->getFrameStamp();
double referenceTime = fs->getReferenceTime();
if (_firstCall)
{
_firstCall = false;
_startTime = referenceTime;
}
_time = referenceTime-_startTime;
drawable->accept(*this);
drawable->dirtyBound();
osg::Geometry* geometry = dynamic_cast<osg::Geometry*>(drawable);
if (geometry)
{
osgUtil::SmoothingVisitor::smooth(*geometry);
}
}
virtual void apply(osg::Drawable::AttributeType type,unsigned int count,osg::Vec3* begin)
{
if (type == osg::Drawable::VERTICES)
{
const float TwoPI=2.0f*osg::PI;
const float phase = -_time/_period;
osg::Vec3* end = begin+count;
for (osg::Vec3* itr=begin;itr<end;++itr)
{
osg::Vec3 dv(*itr-_origin);
osg::Vec3 local(dv*_xAxis,dv*_yAxis,dv*_zAxis);
local.z() = local.x()*_amplitude*
sinf(TwoPI*(phase+local.x()*_xphase));
(*itr) = _origin +
_xAxis*local.x()+
_yAxis*local.y()+
_zAxis*local.z();
}
}
}
bool _firstCall;
double _startTime;
double _time;
double _period;
double _xphase;
float _amplitude;
osg::Vec3 _origin;
osg::Vec3 _xAxis;
osg::Vec3 _yAxis;
osg::Vec3 _zAxis;
};
osg::Node* createPreRenderSubGraph(osg::Node* subgraph, unsigned tex_width, unsigned tex_height, osg::CameraNode::RenderTargetImplementation renderImplementation)
{
if (!subgraph) return 0;
// create a group to contain the flag and the pre rendering camera.
osg::Group* parent = new osg::Group;
// texture to render to and to use for rendering of flag.
osg::Texture2D* texture = new osg::Texture2D;
texture->setTextureSize(tex_width, tex_height);
texture->setInternalFormat(GL_RGBA);
texture->setFilter(osg::Texture2D::MIN_FILTER,osg::Texture2D::LINEAR);
texture->setFilter(osg::Texture2D::MAG_FILTER,osg::Texture2D::LINEAR);
// first create the geometry of the flag of which to view.
{
// create the to visualize.
osg::Geometry* polyGeom = new osg::Geometry();
polyGeom->setSupportsDisplayList(false);
osg::Vec3 origin(0.0f,0.0f,0.0f);
osg::Vec3 xAxis(1.0f,0.0f,0.0f);
osg::Vec3 yAxis(0.0f,0.0f,1.0f);
osg::Vec3 zAxis(0.0f,-1.0f,0.0f);
float height = 100.0f;
float width = 200.0f;
int noSteps = 20;
osg::Vec3Array* vertices = new osg::Vec3Array;
osg::Vec3 bottom = origin;
osg::Vec3 top = origin; top.z()+= height;
osg::Vec3 dv = xAxis*(width/((float)(noSteps-1)));
osg::Vec2Array* texcoords = new osg::Vec2Array;
osg::Vec2 bottom_texcoord(0.0f,0.0f);
osg::Vec2 top_texcoord(0.0f,1.0f);
osg::Vec2 dv_texcoord(1.0f/(float)(noSteps-1),0.0f);
for(int i=0;i<noSteps;++i)
{
vertices->push_back(top);
vertices->push_back(bottom);
top+=dv;
bottom+=dv;
texcoords->push_back(top_texcoord);
texcoords->push_back(bottom_texcoord);
top_texcoord+=dv_texcoord;
bottom_texcoord+=dv_texcoord;
}
// pass the created vertex array to the points geometry object.
polyGeom->setVertexArray(vertices);
polyGeom->setTexCoordArray(0,texcoords);
osg::Vec4Array* colors = new osg::Vec4Array;
colors->push_back(osg::Vec4(1.0f,1.0f,1.0f,1.0f));
polyGeom->setColorArray(colors);
polyGeom->setColorBinding(osg::Geometry::BIND_OVERALL);
polyGeom->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUAD_STRIP,0,vertices->size()));
// new we need to add the texture to the Drawable, we do so by creating a
// StateSet to contain the Texture StateAttribute.
osg::StateSet* stateset = new osg::StateSet;
stateset->setTextureAttributeAndModes(0, texture,osg::StateAttribute::ON);
polyGeom->setStateSet(stateset);
polyGeom->setUpdateCallback(new MyGeometryCallback(origin,xAxis,yAxis,zAxis,1.0,1.0/width,0.2f));
osg::Geode* geode = new osg::Geode();
geode->addDrawable(polyGeom);
parent->addChild(geode);
}
// then create the camera node to do the render to texture
{
osg::CameraNode* camera = new osg::CameraNode;
// set up the background color and clear mask.
camera->setClearColor(osg::Vec4(0.1f,0.1f,0.3f,1.0f));
camera->setClearMask(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
const osg::BoundingSphere& bs = subgraph->getBound();
if (!bs.valid())
{
return subgraph;
}
float znear = 1.0f*bs.radius();
float zfar = 3.0f*bs.radius();
// 2:1 aspect ratio as per flag geomtry below.
float proj_top = 0.25f*znear;
float proj_right = 0.5f*znear;
znear *= 0.9f;
zfar *= 1.1f;
// set up projection.
camera->setProjectionMatrixAsFrustum(-proj_right,proj_right,-proj_top,proj_top,znear,zfar);
// set view
camera->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
camera->setViewMatrixAsLookAt(bs.center()-osg::Vec3(0.0f,2.0f,0.0f)*bs.radius(),bs.center(),osg::Vec3(0.0f,0.0f,1.0f));
// set viewport
camera->setViewport(0,0,tex_width,tex_height);
// set the camera to render before the main camera.
camera->setRenderOrder(osg::CameraNode::PRE_RENDER);
// tell the camera to use OpenGL frame buffer object where supported.
camera->setRenderTargetImplmentation(renderImplementation);
// attach the texture and use it as the color buffer.
camera->attach(osg::CameraNode::COLOR_BUFFER, texture);
// add subgraph to render
camera->addChild(subgraph);
parent->addChild(camera);
}
return parent;
}
int main( int argc, char **argv )
{
// use an ArgumentParser object to manage the program arguments.
osg::ArgumentParser arguments(&argc,argv);
// set up the usage document, in case we need to print out how to use this program.
arguments.getApplicationUsage()->setDescription(arguments.getApplicationName()+" is the example which demonstrates pre rendering of scene to a texture, and then apply this texture to geometry.");
arguments.getApplicationUsage()->setCommandLineUsage(arguments.getApplicationName()+" [options] filename ...");
arguments.getApplicationUsage()->addCommandLineOption("-h or --help","Display this information");
arguments.getApplicationUsage()->addCommandLineOption("--fbo","Use Frame Buffer Object for render to texture, where supported.");
arguments.getApplicationUsage()->addCommandLineOption("--fb","Use FrameBuffer for render to texture.");
arguments.getApplicationUsage()->addCommandLineOption("--pbuffer","Use Pixel Buffer for render to texture, where supported.");
arguments.getApplicationUsage()->addCommandLineOption("--window","Use a seperate Window for render to texture.");
arguments.getApplicationUsage()->addCommandLineOption("--width","Set the width of the render to texture");
arguments.getApplicationUsage()->addCommandLineOption("--height","Set the height of the render to texture");
// construct the viewer.
osgProducer::Viewer viewer(arguments);
// set up the value with sensible default event handlers.
viewer.setUpViewer(osgProducer::Viewer::STANDARD_SETTINGS);
// get details on keyboard and mouse bindings used by the viewer.
viewer.getUsage(*arguments.getApplicationUsage());
// if user request help write it out to cout.
if (arguments.read("-h") || arguments.read("--help"))
{
arguments.getApplicationUsage()->write(std::cout);
return 1;
}
unsigned tex_width = 1024;
unsigned tex_height = 512;
while (arguments.read("--width", tex_width)) {}
while (arguments.read("--height", tex_height)) {}
osg::CameraNode::RenderTargetImplementation renderImplementation = osg::CameraNode::FRAME_BUFFER_OBJECT;
while (arguments.read("--fbo")) { renderImplementation = osg::CameraNode::FRAME_BUFFER_OBJECT; }
while (arguments.read("--pbuffer")) { renderImplementation = osg::CameraNode::PIXEL_BUFFER; }
while (arguments.read("--fb")) { renderImplementation = osg::CameraNode::FRAME_BUFFER; }
while (arguments.read("--window")) { renderImplementation = osg::CameraNode::SEPERATE_WINDOW; }
// any option left unread are converted into errors to write out later.
arguments.reportRemainingOptionsAsUnrecognized();
// report any errors if they have occured when parsing the program aguments.
if (arguments.errors())
{
arguments.writeErrorMessages(std::cout);
return 1;
}
if (arguments.argc()<=1)
{
arguments.getApplicationUsage()->write(std::cout,osg::ApplicationUsage::COMMAND_LINE_OPTION);
return 1;
}
// load the nodes from the commandline arguments.
osg::Node* loadedModel = osgDB::readNodeFiles(arguments);
if (!loadedModel)
{
return 1;
}
// create a transform to spin the model.
osg::MatrixTransform* loadedModelTransform = new osg::MatrixTransform;
loadedModelTransform->addChild(loadedModel);
osg::NodeCallback* nc = new osgUtil::TransformCallback(loadedModelTransform->getBound().center(),osg::Vec3(0.0f,0.0f,1.0f),osg::inDegrees(45.0f));
loadedModelTransform->setUpdateCallback(nc);
osg::Group* rootNode = new osg::Group();
rootNode->addChild(createPreRenderSubGraph(loadedModelTransform,tex_width,tex_height, renderImplementation));
// add model to the viewer.
viewer.setSceneData( rootNode );
// create the windows and run the threads.
viewer.realize();
while( !viewer.done() )
{
// wait for all cull and draw threads to complete.
viewer.sync();
// update the scene by traversing it with the the update visitor which will
// call all node update callbacks and animations.
viewer.update();
// fire off the cull and draw traversals of the scene.
viewer.frame();
}
// wait for all cull and draw threads to complete before exit.
viewer.sync();
return 0;
}