[osg-users] Texture Caching Problem with 3.6.3/4

[OpenSceneGraph Users]

Hi Robert,
I stumbled upon this topic while I was looking for a similar problem that I 
am having using osgEarth in an osgQt viewer. I am posting this message here 
because I think that the two problems might be related and I hope that you 
could help me. I am using OpenSceneGraph-3.6.5 and osgearth-2.10.1.

I noticed it while I was coding my application but recently I saw that the 
same error messages are displayed by osgviewerQt as well.
I am using a demo.earth file that uses local geotiff files stacked in a 
composite image and, above that, I placed the following cache configuration:

<options>
  <cache driver="filesystem">
    <path>/home/emanuele/mapsCache</path>
  </cache>
</options>

If I run "osgviewer demo.earth", the globe is shown without any error 
messages but if I run "osgviewerQt demo.earth", it happens something 
similar to what Greg described in his post: if I run osgviewerQt with an 
empty cache folder, no messages are printed but when I run osgviewerQt 
again, a few error messages are printed... and I am not sure if the program 
is loading images from the cache folder or from the specified files. The 
messages disappear if I remove the cache section from the earth file.
They are the following:

[osgEarth]* JSON decoding error: * Line 1, Column 67
  Missing '}' or object member name

[osgEarth]* [TerrainLayer] Layer "image" Metadata appears to be corrupt.
[osgEarth]* JSON decoding error: * Line 1, Column 67
  Missing '}' or object member name

[osgEarth]* [TerrainLayer] Layer "Elevation2" Metadata appears to be 
corrupt.
[osgEarth]* JSON decoding error: * Line 1, Column 67
  Missing '}' or object member name

[osgEarth]* [TerrainLayer] Layer "Elevation1" Metadata appears to be 
corrupt.
[osgEarth]* JSON decoding error: * Line 1, Column 67
  Missing '}' or object member name

[osgEarth]* [TerrainLayer] Layer "world-tiff" Metadata appears to be 
corrupt.
[osgEarth]* JSON decoding error: * Line 1, Column 67
  Missing '}' or object member name

[osgEarth]* [TerrainLayer] Layer "SermonetaWide" Metadata appears to be 
corrupt.
[osgEarth]* JSON decoding error: * Line 1, Column 67
  Missing '}' or object member name

The first error messages are printed as soon as I run the program, the 
following appear when I zoom on the map.
I have already talked with Glenn Waldron (osgEarth) about this messages and 
he thinks that, since osgviewer is working fine, they might be related to 
some threading issues in osgQt.

I'd really appreciate your help. Thank you,
 Emanuele

Il giorno lunedì 16 dicembre 2019 18:08:34 UTC+1, Robert Osfield ha scritto:
>
> Hi Greg,
>
> Today I worked on improving the ObectCache::releaseGLObjects() 
> implementation so that it removes objects in the scene that are Texture or 
> contain Textures in their subgraph, where the Texture no longer have any 
> associated osg::Image. I believe this resolves the usage case :
>
>   1.  Load the scene graph, with the Texture UnRefImageAfterApply setiings 
> are set to UnrefImageAfterApply, with the loaded textures/scene graphs 
> being cached in the osgDB::ObjectCache.
>   2. Render the scene graph, resulting the in the scene graph images being 
> unref'd from their Textures.
>   3. Close the Window, which cleans up the scene graph GL obects by 
> calling releaseGLObjects()
>   4. Load a new scene graph with textures/objects loaded from disk and 
> where possible from the ObjectCache if previously loaded and cache,  Got 
> back to 2. (Rendering etc.)
>
> I created an example that follows all these steps and it reproduced the 
> problem with the textures appearing black on the second time around when 
> loading an OpenFlight database.  With the fixes to 
> ObjectCache::releaseGLObjects() the unref'd images are automatically 
> removed from the cache as part of step 3. above, so that they aren't shared 
> any more, instead new copies are loaded from disk with their image in place.
>
> This fix is checked into the OpenSceneGraph-3.6 branch.  The commit is:
>
>     
> https://github.com/openscenegraph/OpenSceneGraph/commit/9ae47b921b2184788e6efe85692908bd0ba900a2
>
> Could you please test this out.  You should be able to remove your own 
> manually clearing of the ObjectCache now, as it will be done automatically 
> when required.
>
> Cheers,
> Robert.
>

-- 
You received this message because you are subscribed to the Google Groups "OpenSceneGraph Users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to osg-users+unsubscribe at googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/osg-users/93b6ffd8-b2e6-43c0-a6c8-3ef11949bbaf%40googlegroups.com.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openscenegraph.org/pipermail/osg-users-openscenegraph.org/attachments/20200331/b51d8dc7/attachment.html>