Carpet textures "flicker" and get hidden by ground texture

[fabio]

Persian civic center has 4 of carpets on it. When you zoom or rotate the screen, 3 of the carpets on it (the two in front and the one on the back) "flicker" and get partially hidden by the ground texture (the one just behind the first two in the front seems not affected by this problem).

Since llvmpipe (software render) doesn't have this problem, as well other videos and screenshots found on the net, I previously reported this bug against the mesa r300 gallium graphics driver: ​https://bugs.freedesktop.org/show_bug.cgi?id=44126

However, as it is the case with #2143, this may be a limit of old graphics chips (confused by different textures on the same layer), which could eventually workarounded in 0ad. Maybe the affected carpets should be pushed a bit up (or they anyway could put the same as the not affected carpet).

Status update:

• two front carpets of Persan CC: fixed in r15700
• rear carpet Persian CC: bugged
• hieroglyphics on Ptol CC: bugged

An example screenshot is shown below:

[Stan]

I can't reproduce it, can anyone check ?

[Pureon]

In 15700:

Updated Persian Civic structure. Fixes #2630

[Pureon]

I moved the carpets up a bit more. Let me know if the bug still happens.

[fabio]

same issue on ptol CC

[fabio]

It works fine now, indeed! I have the same problem with the hieroglyphics on ptol CC however:

Could you do the same with it?

[fabio]

The response of an AMD driver developer on mesa bugzilla was:

Flickering when 2 primitives exactly intersect each other and vertex positions are not equal is a quite common programming mistake in games. Drivers cannot do anything about it.

Maybe this should be reminded in the models how-to available on wfg?

[fabio]

Also the third carpet of the original issue, the one near the back, is still not fixed.

[historic_bruno]

I'm not sure anyone on the art team checks Trac, maybe a post in the art development forum is needed.

[Stan]

I ´m the only one doing th junction so it would indeed be a good idea.

[fabio]

Reported also on forum here: http://www.wildfiregames.com/forum/index.php?showtopic=19557

[Enrique]

Cannot reporduce. Geometry is not intersecting, polygons are close but they're not ovelapping -"not occupying the same space"

[Enrique]

Closed the ticket after further testing.