Donny, <div><br></div><div>Were you talking about hidden lines removal may be? </div><div><br></div><div>Thanks, </div><div><br></div><div><br></div><div><br></div><div><br><div class="gmail_quote">On Thu, Nov 18, 2010 at 9:03 AM, David Gobbi <span dir="ltr"><<a href="mailto:david.gobbi@gmail.com">david.gobbi@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">Jerome is correct, OpenGL culls faces according to the polygon<br>
winding. So wireframe polygons can be culled, but polylines cannot,<br>
even if they have normals assigned to them. There are some details in<br>
the OpenGL FAQ:<br>
<a href="http://www.opengl.org/resources/faq/technical/clipping.htm" target="_blank">http://www.opengl.org/resources/faq/technical/clipping.htm</a><br>
<font color="#888888"><br>
David<br>
</font><div><div></div><div class="h5"><br>
On Wed, Nov 17, 2010 at 11:47 PM, Jérôme <<a href="mailto:jerome.velut@gmail.com">jerome.velut@gmail.com</a>> wrote:<br>
> Hi Donny,<br>
><br>
> My feeling is that backface culling should not work with polylines because they<br>
> have actually no face.<br>
><br>
> Jerome<br>
><br>
> 2010/11/18 Donny <<a href="mailto:donnyz@charter.net">donnyz@charter.net</a>>:<br>
>> I am drawing polylines using vtkPolyData and cannot get backface culling to<br>
>> work with them.<br>
>><br>
>><br>
>><br>
>> I ran into this subject<br>
>> <a href="http://public.kitware.com/pipermail/vtkusers/2003-January/065023.html" target="_blank">http://public.kitware.com/pipermail/vtkusers/2003-January/065023.html</a> , but<br>
>> did not help.<br>
>><br>
>><br>
>><br>
>> Any solutions?<br>
>><br>
>><br>
>><br>
>> Donny Zimmerman<br>
>><br>
>> <a href="mailto:donnyz@charter.net">donnyz@charter.net</a><br>
>><br>
>> 308-227-1756<br>
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