Hi everyone, I am working on a system to drag and drop shapes into the scenegraph in a Qt application. I have the ability to drag shapes from a list widget into the QOSGWidget and then render the shape at (0, 0, 0). What I would like to do is modify this to attach the shape to the mouse so the user can place the shape where they want instead of just plopping it at the origin. I'm using a GUIEventHandler to get the mouse position of the drop, then I am trying to covert the mouse coordinates into the scenegraph world coordinates. I've managed to get this working because I am right now rendering dummy spheres and they show up directly under the mouse. However, I would like to be able to have the coordinate be modified so the y-position is always at zero so the shapes are being drug in the xz plane. This would make a lot more sense to a user when the place the shape. I just can't figure out how to take my world space coordinate, zero out the y-position, and modify the xz values so that the sp heres still show up under the mouse.
Here's the code I'm using to convert the mouse position into world coordinates: Code: v3 mousePos(ea.getX(), _widgetHeight - ea.getY(), 0.0f); osg::Matrix viewMatrix = viewer->getCamera()->getViewMatrix(); osg::Matrix projectionMatrix = viewer->getCamera()->getProjectionMatrix(); osg::Matrix windowMatrix = viewer->getCamera()->getViewport()->computeWindowMatrix(); osg::Matrix cameraMatrix = viewMatrix * projectionMatrix * windowMatrix; osg::Matrix inverseCameraMatrix; inverseCameraMatrix.invert(cameraMatrix); v3 newPos = mousePos * inverseCameraMatrix; Anyone have any insight as to how I can move the newPos down to a y-value of 0.0f and still have it show up under the mouse? I've used LineSegmenetIntersectors before for doing this sort of thing, but they only work if you are intersecting with geometry. A really hacked solution I can think of is to render a big xz plane and use a line segment intersector to find the intersection point. But this just seems like a really bad approach, even if I hide the plane. Thanks for all the help! Cheers, Christian ------------------ Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=33709#33709 _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
