Hi David,
There could be couple of reasons, but I can't work out from your post
exactly what is not working and where so I'll provide some general
suggestions as to what might be wrong, but given I don't know what the
actual problem is I can't provide any suggestions as to how one might
fix it.
1) Could it be z fighting? The line is disappearing under the geometry? Try
putting the scene in wireframe so that polygons won't obscure hidden lines.
2) Could it be a numerical precision issue? VPB uses local MatrixTransform
to place tiles with a local coordinate frame into ECEF to avoid precision
issues.
3) Near plan clipping?
Robert.
On Mon, Jul 12, 2010 at 9:19 PM, David Glenn <[email protected]> wrote:
> Greetings All!
>
> I hate to come up with another stupid one, but I've been banging my head with
> this one!
>
> One of the displays I doing has an ellipsoid globe appearing and above that,
> I have some Overlay lines (what we call MOA lines) or marker lines. I have
> them drawn above the globe and from a normal view the lines and polygons
> appear as they should.
>
> Note: I'm using a camera that is using the terrain manipulator to control so
> I can zoom in and out move east west north south.
>
> I'm using:
>
> Code:
>
> linesOverlay->addPrimitiveSet(new osg::DrawArrays(GL_LINE_LOOP,0,numPts));
>
>
>
> to draw the line loop and
>
> Code:
>
> linesOverlay->addPrimitiveSet(new osg::DrawArrays(GL_POLYGON,0,numPts));
>
>
>
> to draw a filled polygon.
>
> linesOverlay is a Geometry class and I'm adding it to a Grode using the
> addDrawable command.
>
> Well, I noticed that when I zoom in on the polygon. that it appears normal,
> but using the same data points for drawing a line loop, when I zoom in on a
> line, I will get to within 2000 meters of the line and it will start
> disappear. first at the middle of the focus point of the camera, then outward
> as I continue to zoom in!
>
> Note: I had similar problem with my polygon elements that seem to be getting
> cut off by my near camera plane. I readjusted the near/far ratio that seemed
> to fix it, but maybe that was the wrong approach?
>
> FYI: I'm using OSG 2.8.1
>
> I must be goofing up someware!
> Any Ideas? Grin!
> ...
> D Glenn
>
> ------------------------
> D Glenn (a.k.a David Glenn) - Join the Navy and See the World ... from your
> Desk!
>
> ------------------
> Read this topic online here:
> http://forum.openscenegraph.org/viewtopic.php?p=29937#29937
>
>
>
>
>
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