<html> <head> <meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type"> </head> <body text="#000000" bgcolor="#FFFFFF"> <div class="moz-cite-prefix">On 11/06/2013 12:58 PM, Brian Paul wrote: </div> <blockquote cite="mid:527AAD5C.2000804@vmware.com" type="cite">On 11/06/2013 12:34 PM, burlen wrote: <blockquote type="cite">When I build osmesa with --with-osmesa-bits=32 I notice that I get 31 bits by way of the compile line define -DDEFAULT_SOFTWARE_DEPTH_BITS=31. What's the story with the number 31? Is 31 bits really better than 32? </blockquote> IIRC, 32 bit Z never worked properly because of float->int conversion problems and such. I think I found that 31 bits worked though. It's been a long time... </blockquote> I'm using OSMesa with VTK for rendering on systems that do not have graphics hardware. I need higher than default depth buffer with OSMesa to prevent z-buffer fighting artifacts in some cases when rendering in parallel. I found that --with-osmesa-bits=32 does the trick. however when building osmesa with 32 bits, most line rendering fails. Here is a representative image diff from our regression suite that shows an example of the bug <meta http-equiv="content-type" content="text/html; charset=ISO-8859-1"> <a href="http://open.cdash.org/testDetails.php?test=216532438&build=3087854">http://open.cdash.org/testDetails.php?test=216532438&build=3087854</a> , there are 80 other failed tests, the ones I examined were all the same. Experimenting with --with-osmesa-bits options, I've found that using 32 causes the issue, while using 8 , 16 or not using it all doesn't. Do you have any idea about this? Thanks Burlen </body> </html>