Behavior is expected to be simillar to 'make proxy' on linked groups, it
basically allows you to select which object in the group will be to
'root' override (usually, the armature), checks which other objects
needs to be overridden as well, overrides the group itself too, and
instantiates the group and the root overridden object.
It seems to be working, though handling of armature deformation is kind
of totally broken in blender2.8 currently (modifiers...). ;)
At some point, we could probably think about removing IRIS file format
support, don't think there are much of those around anymore. But for
now, let's add a translation context to wipe effect. :)
Reported in T43295 by @blend-it, thanks.
I was calling the ntree syncing function too late. So the index of the layer
was -1 since it was no longer in the ListBase, making all RenderLayer nodes
to decrease their respective `custom1` (even going to negative sometimes).
Since 30a966a726 when I removed the recursion, the code was still relying
on stack data. This would crash in release often, and it should crash always.
Big thanks to Sergey Sharybin for spotting the issue.
The issue was introduced by eb016eb as a fix for T41258, which added depsgraph
tagging with zero flag. The comment was saying that it's to make derived caches
to be updated, however bot sure how that could possibly work: tagging ID for
update with 0 flag only sets updated tags in bmain in old dependency graph.
In the new depsgraph, where object data is a part of depsgraph, doing such a
tag forces object to be updated, which re-triggers viewport rendering, which
is causing such an infinite viewport render rest.
Can not reproduce any crashes here, so maybe it's fine to move on with this
change.
This was leading to so much recursion that it was failing here.
How to test it: Open wanderer.blend and try to render (F12).
Note: This won't fix F12 rendering for wanderer with Eevee. Something else is
going wrong there.
For simplicity we choose to execute the rendering of Opengl engines in the main thread and block the interface.
This might be addressed in the future at least for video rendering.
A drawmanager wrapper (DRW_render_to_image) is called by the render pipeline to set up the Opengl state and then call the specific draw_engine->render_to_image function.
