Thanks a lot for you replies! I tried to use the code but so far without
success. At most I get a completely black image, but sometimes the
SnapImageDrawcallback's operator() is never even called..
Here is my code. What exactly am I doing wrong here?
class SnapImageDrawCallback : public
::osg::CameraNode::DrawCallback
{
public:
SnapImageDrawCallback()
{
_snapImageOnNextFrame = false;
}
void setFileName(const std::string& filename) {
_filename = filename; }
const std::string& getFileName() const { return
_filename; }
void setSnapImageOnNextFrame(bool flag) {
_snapImageOnNextFrame = flag; }
bool getSnapImageOnNextFrame() const { return
_snapImageOnNextFrame; }
virtual void operator () (const
::osg::CameraNode& camera) const
{
::osg::notify(::osg::NOTICE) << "Saving
screen image to '"<<_filename<<"'"<< std::endl;
if (!_snapImageOnNextFrame) return;
int x,y,width,height;
x = camera.getViewport()->x();
y = camera.getViewport()->y();
width = camera.getViewport()->width();
height =
camera.getViewport()->height();
::osg::ref_ptr< ::osg::Image> image =
new ::osg::Image();
image->readPixels(x,y,width,height,GL_RGB,GL_UNSIGNED_BYTE);
if
(::osgDB::writeImageFile(*image,_filename))
{
std::cout << "Saved screen
image to '"<<_filename<<"'"<< std::endl;
}
_snapImageOnNextFrame = false;
}
protected:
::std::string _filename;
mutable bool _snapImageOnNextFrame;
};
void
renderSceneToImage(::osg::Node* pRoot, const
::std::string& sFileName_)
{
int nWidth = 640, nHeight = 480;
::osgViewer::Viewer * viewer = new
::osgViewer::Viewer();
viewer->setSceneData(pRoot);
viewer->getCamera()->setRenderTargetImplementation(::osg::CameraNode::FRAME_BUFFER_OBJECT);
::osg::ref_ptr<SnapImageDrawCallback>
snapImageDrawCallback = new SnapImageDrawCallback();
viewer->getCamera()->setPostDrawCallback
(snapImageDrawCallback.get());
snapImageDrawCallback->setFileName(sFileName_);
snapImageDrawCallback->setSnapImageOnNextFrame(true);
::osg::ref_ptr< ::osg::GraphicsContext> pbuffer;
::osg::ref_ptr< ::osg::GraphicsContext::Traits>
traits = new ::osg::GraphicsContext::Traits;
traits->x = 0;
traits->y = 0;
traits->width = nWidth;
traits->height = nHeight;
traits->red = 8;
traits->green = 8;
traits->blue = 8;
traits->alpha = 8;
traits->windowDecoration = false;
traits->pbuffer = true;
traits->doubleBuffer = true;
traits->sharedContext = 0;
pbuffer =
::osg::GraphicsContext::createGraphicsContext(traits.get());
if (pbuffer.valid())
{
::osg::ref_ptr< ::osg::Camera> camera2
= new ::osg::Camera();
camera2->setGraphicsContext(pbuffer.get());
GLenum buffer =
pbuffer->getTraits()->doubleBuffer ? GL_BACK : GL_FRONT;
camera2->setDrawBuffer(buffer);
camera2->setReadBuffer(buffer);
viewer->addSlave(camera2.get(),
::osg::Matrixd(), ::osg::Matrixd());
}
viewer->realize();
viewer->frame();
}
------------------
Read this topic online here:
http://forum.openscenegraph.org/viewtopic.php?p=33869#33869
_______________________________________________
osg-users mailing list
[email protected]
http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
