z buffer problem in mac os x

In my application I draw a wall which consists of an inner quad (plain white) and an outer quad (textured with bricks).

In my camera setup I set the near-far plates to 1-2000 which works great in windows, but in mac when I zoom out the renderer draws the inner quad in front of the outer quad.

If I change the near plate from 1 to 10, it helps but if I zoom farther it does it again.

Why is it that the z buffer seem to be so inaccurate in mac os x but very accurate in windows?

Hi

Which version of Mac OS X and which graphics card do you use?

The test laptop is MacBook Pro:

Mac OS X 10.6.8
Graphics card: nvidia Geforce 9400M GT

Although I suspect it behaves this way in any Mac.

No it's not possible. Maybe Sven can confirm. I have no Mac.

If you send me a nice and neat test case for eclipse, I would test it on my mac mini.

Pixelapp, could you please test our executable in your mac?

it can be found free here:

http://energy.concord.org/energy3d/index.html

Both webstart and application versions are available in the above site.

After starting it, try drawing a wall so that the bricks face the camera. Then zoom out with mouse wheel, or the zoom toolbar bottom, until it stops. It shouldn't take long until you see that the white polygon behind the wall is rendered instead of the brick textured polygon in front.

On 12/10/2012 05:09 PM, runiter [via jogamp] wrote: Please provide a unit test, so we can verify this issue.
(use one of our many unit tests as a template ..)

Thank you.

~Sven

You should have a look :
http://blog.richeton.com/2007/05/09/swt-lwjgl-macos-the-depth-buffer-problem-in-opengl/

Thank you all. It turned out that there is nothing wrong with z buffer in mac.
The problem was that polygonOffset was behaving differently in mac os x.

In my project when you draw a wall, some annotation lines are drawn on it. These lines flicker or hide under the wall polygon so I was forced to use PolygonOffset. Unfortunately in OpenGL PolygonOffset doesn't have any effect on lines (am I correct?) so I had to offset the wall mesh. But doing that caused Mac OS X to render the back mesh in front.

So now I went through every single mesh in my scene and offset all of them except the lines. Is this the way to go? or was there an easier way?

Polygon offset (sometimes called depth bias) doesn't work consistently across drivers, I used it in the alpha version of my game and I will have to consider other solutions because it is not satisfying.