Hi Tim,
many thanx for the answer! Dividing the vector by w was the hint I needed. Now
it works.
Best regards,
Oli
Am Samstag, 2. Oktober 2010, 13:13:35 schrieb Tim Moore:
> On Sat, Oct 2, 2010 at 4:47 AM, Oliver Burtchen <o.burtc...@gmx.de> wrote:
> > Hello at all,
> >
> > I'm currently working on frustum-culling for a
> > roam-algorithm-implemetation.
> > Maybe someone can give me a hint what I'm missing to nail my problem
> > down.
> >
> > I want to calculate the x,y-coordinates for a vertex on the screen. My
> > approach (only for testing, to nail down the problem):
> >
> > <code>
> >
> > osg::Matrixd mv = osg::Matrixd::identity();
> > osg::Matrixd mp = osg::Matrixd::identity();
> > osg::Matrixd mw = osg::Matrixd::identity();
> >
> > while( !viewer.done() )
> > {
> >
> > viewer.frame();
> >
> > if (viewer.getCameraWithFocus())
> > {
> >
> > mv = viewer.getCameraWithFocus()->getViewMatrix();
> > mp = viewer.getCameraWithFocus()->getProjectionMatrix();
> > mw =
> > viewer.getCameraWithFocus()->getViewport()->computeWindowMatrix();
> >
> > }
> >
> > }
> >
> > osg::Vec4d v = osg::Vec4d(0, 0, 0, 1.0);
> > v = v * mv;
> > v.normalize();
>
> No! don't normalize there.
>
> > v = v * mp * mw;
> >
> > This is fine, now you need to divide v by v.w().
>
> Tim
>
> > </code>
> >
> >
> > Schould this give me the last-coordinates of v on the screen, when
> > pressing "ESC" so the viewer terminates? I know this code only works, if
> > the window has
> > the focus at termination-time, this is not the problem why I'm asking.
> >
> > Best regards,
> > Oli
> >
> > --
> > Oliver Burtchen, Berlin
> > _______________________________________________
> > osg-users mailing list
> > osg-users@lists.openscenegraph.org
> > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
--
Oliver Burtchen, Berlin
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