For my application, I use this function to extract the origin and the
direction of a 2d point on the screen. My windowing system here is Qt.
I can't say this is the most efficient way to get the answer, but it works.
void QOpenSceneGraph::xyVector(const QPoint &screenpoint, osg::Vec3d
&origin, osg::Vec3d &direction)
{
osg::Matrix mat =
osg::Matrix::inverse(m_SceneView->getProjectionMatrix());
osg::Matrix cameramatrix = this->getCameraMatrix();
osg::Matrix cameramatrixnotrans = cameramatrix;
cameramatrixnotrans.setTrans(0,0,0);
osg::Vec4d d = osg::Vec4(
((double)screenpoint.x() / (double)this->width()) * 2.0 -
1.0,
-(((double)screenpoint.y() / (double)this->height()) * 2.0 -
1.0),
0.0,1.0);
d = d * mat;
d = d * cameramatrixnotrans;
direction.set(d[0],d[1],d[2]);
direction.normalize();
origin = cameramatrix.getTrans();
}
On Mon, Mar 9, 2009 at 2:31 PM, Ben Axelrod <baxel...@coroware.com> wrote:
> I have been using osgUtil::PickVisitor for a while now to pick objects in
> my tree under the mouse. But now I need to cast a ray into the scene under
> the mouse and manually intersect it with an imaginary plane. Is there some
> helper function to do this mouse ray cast for me? Specifically, something
> that would take as input 2 ints for the position of the mouse, and maybe the
> camera or projection and view matrices, then output a vector?
>
>
>
> Thanks,
>
> -Ben
>
> _______________________________________________
> osg-users mailing list
> osg-users@lists.openscenegraph.org
> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
>
>
_______________________________________________
osg-users mailing list
osg-users@lists.openscenegraph.org
http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
