There is some texture corruption in Unigine Sanctuary v2.3, it looks almost like if you were watching very low quality video.
83ebc01c1dd1cd8a960a2a61fc7203f8312644d5 is the first bad commit
Author: Dave Airlie <email@example.com>
Date: Fri Feb 25 09:24:15 2011 +1000
mesa/st: add RGTC format support.
this just adds a format check + format conversion.
Workaround is MESA_EXTENSION_OVERRIDE="-GL_ARB_texture_compression_rgtc -GL_EXT_texture_compression_rgtc".
Fixed with commit 7a61957424a457f416d20c2b366232fb4bbc7761. Closing..