Bug 2068 - Depth buffer issues with transparent objects (Unichrome).
Summary: Depth buffer issues with transparent objects (Unichrome).
Alias: None
Product: Mesa
Classification: Unclassified
Component: Drivers/DRI/Unichrome (show other bugs)
Version: git
Hardware: x86 (IA32) Linux (All)
: high normal
Assignee: Default DRI bug account
QA Contact:
Depends on:
Reported: 2004-12-12 14:18 UTC by Thomas Hellström
Modified: 2015-11-30 23:44 UTC (History)
1 user (show)

See Also:
i915 platform:
i915 features:


Note You need to log in before you can comment on or make changes to this bug.
Description Thomas Hellström 2004-12-12 14:18:53 UTC
There seems to be depth buffer issues with transparent objects with the Unichrome. 
Although the objects are not visible against the background since they are
transparent, they seem to somehow obscure other objects. Perhaps objects that
get drawn later. 

To reproduce: 
Launch tucracer. At the beginning of the first lap, Tux will suddenly disappear,
and then reappear again.

Also at the start of the second level, The starting banner seems to be obscured
by a transparent object.
Comment 1 Felix Kühling 2004-12-12 18:39:27 UTC
Sounds like the alpha test is broken. I vaguely remember fixing a related
problem in the Savage driver once. On the Savage there is a bit that says "write
Z after alpha test". If you don't set that bit then fragments that fail the
alpha test still write a Z value so that they "obscure" stuff that is drawn later.
Comment 2 Adam Jackson 2009-08-24 12:22:55 UTC
Mass version move, cvs -> git
Comment 3 Ian Romanick 2015-11-30 23:44:40 UTC
The Unichrome driver longer exists in Mesa.

Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.