Re: [PyOpenGL-Users] culling with tétrahedron

[Roland E. <r.e...@gm...>]

Ian,

After some experiment based on what you say about the winding, I figure 
the problem, and now I have the correct behavior. But that still doesn't 
explain why GL_CULL_FACE is doing something, when using GL_LINE.

Roland.

Le 05/15/10 21:52, Roland Everaert a écrit :
> So how to explain that a spinning cube gives me what I want (the 
> verteces not seen by the camera are hidden)?
>
> The code is the same, but where GL_TRIANGLES is replaced by GL_QUADS, 
> the vertices and indices lists are filled accordingly and the 2nd 
> argument of glDrawElements replaced by the len of the indices list. 
> And there is no test on the depth.
>
>
> Thanks,
>
>
> Roland.
>
> Le 05/14/10 23:36, Ian Mallett a écrit :
>> Well, for one thing, you're drawing the tetrahedron in line mode.  
>> GL_CULL_FACE does nothing for GL_LINE.
>>
>> You might also try culling the front faces glCullFace(GL_FRONT).  If 
>> the results are expected, then reverse the winding order of the 
>> polygons (i.e., polygon [v1,v2,v3] specify as [v1,v3,v2]) and cull 
>> the back as before.
>>
>> Ian