Hi Adrian, The OSG by default computes the near and far planes on each frame to optimize the precision of the depth buffer. You can disable this via the osg::Camera as it inherits from osg::CullSettings.
camera->setComputeNearFarMode(osg::CullSettings::DO_NOT_COMPUTE_NEAR_FAR); Whether this is appropriate for your app or not I can't say. Robert. On Fri, Oct 8, 2010 at 11:09 AM, BARRAL Adrien <[email protected]> wrote: > Hello, > > I am using a osg::CameraView to make a "first person view". The CameraView is > attached to a osg::PositionAttitudeTransform node (we will call this node > "Head"). > I can't understand why, but when I tilt the "head", the camera's Znear, and > Zfar value's change... > > I create my CameraView in this way : > > Code: > > m_viewSimulation = new CameraView; > m_viewSimulation->setPosition(Vec3f(0,-.01,0)); > m_viewSimulation->setFieldOfView(45.); > m_viewSimulation->setFieldOfViewMode(CameraView::VERTICAL); > m_viewSimulation->setFocalLength(0.); > m_tiltableHead->addChild(m_viewSimulation); > > > > > Then a CameraViewSwitchManipulator is created to choose wich of all my > cameraview will be the camera's node. > > Tilting the head is done in this way : > > Code: > > Quat cameraAttitude; > cameraAttitude.makeRotate(PI, Vec3f(0.,0.,1.), _tilt, Vec3f(1.,0.,0.), 0, > Vec3f(0,1,0)); > m_tiltableHead->setAttitude(cameraAttitude); > m_camera->setProjectionMatrixAsPerspective(60., 1., 0.01, 1000.); > > > > > Note that I set the projection matrix with a Znear and Zfar each time the > head is tilted. > > Then I get the projection matrix thanks to these lines before, and after the > call to Viewer::frame : > > Code: > > double fovy, ratio, near, far; > m_viewer.getCamera()->getProjectionMatrixAsPerspective(fovy, ratio, near, > far); > cout << "Before :Camera Frustum : FOV Y" <<fovy<<", ratio : "<<ratio<<", near > :"<<near <<", far :" << far<< endl; > > m_viewer.frame(); > > m_viewer.getCamera()->getProjectionMatrixAsPerspective(fovy, ratio, near, > far); > cout << "After :Camera Frustum : FOV Y" <<fovy<<", ratio : "<<ratio<<", near > :"<<near <<", far :" << far<< endl; > > > > > When I run my application, I can see that the cameraview is moving like the > node "TiltableHead", but Znear and Zfar envolve too, look at the console > result of the "cout" : > > > Code: > > Before :Camera Frustum : FOV Y60, ratio : 1, near :0.01, far :1000 > After :Camera Frustum : FOV Y60, ratio : 1, near :2.26244, far :4615.38 > Before :Camera Frustum : FOV Y60, ratio : 1, near :0.01, far :1000 > After :Camera Frustum : FOV Y60, ratio : 1, near :2.26716, far :4625 > Before :Camera Frustum : FOV Y60, ratio : 1, near :0.01, far :1000 > After :Camera Frustum : FOV Y60, ratio : 1, near :2.27232, far :4635.54 > Before :Camera Frustum : FOV Y60, ratio : 1, near :0.01, far :1000 > After :Camera Frustum : FOV Y60, ratio : 1, near :2.2779, far :4646.92 > Before :Camera Frustum : FOV Y60, ratio : 1, near :0.01, far :1000 > After :Camera Frustum : FOV Y60, ratio : 1, near :2.284, far :4659.36 > Before :Camera Frustum : FOV Y60, ratio : 1, near :0.01, far :1000 > After :Camera Frustum : FOV Y60, ratio : 1, near :2.29092, far :4673.47 > Before :Camera Frustum : FOV Y60, ratio : 1, near :0.01, far :1000 > After :Camera Frustum : FOV Y60, ratio : 1, near :2.2976, far :4687.11 > Before :Camera Frustum : FOV Y60, ratio : 1, near :0.01, far :1000 > After :Camera Frustum : FOV Y60, ratio : 1, near :2.30406, far :4700.29 > Before :Camera Frustum : FOV Y60, ratio : 1, near :0.01, far :1000 > After :Camera Frustum : FOV Y60, ratio : 1, near :2.31029, far :4712.99 > Before :Camera Frustum : FOV Y60, ratio : 1, near :0.01, far :1000 > After :Camera Frustum : FOV Y60, ratio : 1, near :2.31629, far :4725.22 > Before :Camera Frustum : FOV Y60, ratio : 1, near :0.01, far :1000 > > > > > > So Why does viewer::Frame change Znear and Zfar ??? > > Cheers, Adrien > > ------------------ > Read this topic online here: > http://forum.openscenegraph.org/viewtopic.php?p=32549#32549 > > > > > > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
