[osg-users] Vanishing letters in osg::Text

[Robert Osfield]

On 25 April 2017 at 06:34, Wouter Roos <rooswouter at gmail.com> wrote:
> I've experienced a similar issue lately where we were running a project on lower spec systems with only an integrated GPU. On those systems the frame rate would not show properly, having the same issue as described here, with some numbers not showing properly.
> I did a test on my laptop, and when I force it to use the integrated GPU (4600) the problems shows up as well. If I switch to use the GTX970M everything is fine again. This is all on Windows 10, osg 3.4.0
> I haven't done any further investigation as the project is not using any Text objects, but maybe this might help somehow.

Some hardware/drivers don't support texture sub-loading correctly so
the osgText subloading of new glyphs could cause problems, perhaps
this is what you are seeing.  It's problem that originally occurred on
Radeon's and some SGI hardware so there is a workaround in osgText
that detects these combinations in drivers, you can also enable the
workaround by setting the env var OSG_TEXT_INCREMENTAL_SUBLOADING to
OFF i.e. under bash you'd do:

  export OSG_TEXT_INCREMENTAL_SUBLOADING=OFF
  osgtext

Under windows I think it's something like:

  set OSG_TEXT_INCREMENTAL_SUBLOADING=OFF
  osgtext

The OSG master version has a had a major rewrite of osgText so it no
longer uses the texture subloading as may well just work out of the
box on the Intel GPU/drivers that you have.

Robert.