Re: Problems with Z-buffer.
Angus Dorbie (dorbie++at++sgi.com)
Fri, 15 May 1998 09:22:49 -0700
Kenneth Sewell wrote:
>
> I have been working on a flight sim that loads in several
> rectangular patches of terrain. The problem is that the z-buffer
> works correctly for the elements of each patch individually but
> not between the elements of two different patches. I apologize
> if I'm not being very clear, I'll give an example. If I have two
> patches A and B (each of them made up of a few thousand
> polygons) with A being closer to the viewer than B. All of
> the polygons in A have been rendered properly with respect
> to each other, all of the polygons of B have been rendered
> properly with respect to each other. However parts of B
> that should be hidden behind A, are drawn as though they
> are nearer. This only happens to part of B, the rest of it is
> behind A, like it should be. I am loading all of the patches
> at the same time and they are all children of one DCS node.
> I would appreciate any help you can offer. Thanks.
>
This is very strange.
Are you sure that you have a zbuffer, could you be getting lucky
with the order of the polygons and just seeing a painters effect
but the tiles are in the wrong order and betray what's really happening?
Cheers,Angus.
--
"Only the mediocre are always at their best." -- Jean Giraudoux
For advanced 3D graphics Performer + OpenGL based examples and tutors:
http://www.dorbie.com/
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on Mon Aug 10 1998 - 17:57:24 PDT