Currently shouldn't make any difference, but this is something what needs to be
done to sanitize drivers relations )with the idea to re-use some generic code
to get operations for driver variables.
Those are unused, and not clear whether we will ever support this.
Seems to be better having more like "component" tags, would be less magic
involved to guess what exactly is to be tagged.
This way we can inform editors about all edits at once. Currently this is not
used, but in the next commits we will inform editors about what exactly has
changed.
Since we are ditching layers from Blender (2.8) we need a replacement to
control groups visibility. This commit introduces collections as the building
blocks for groups, allowing users to control visibility as well as overrides
for groups.
Features
========
* Groups now have collections
This way you can change the visibility of a collection inside a group, and add
overrides which are part of the group and are prioritized over other overrides.
* Outliner
Groups can inspect their collections, change visibility, and add/remove members.
To change an override of a group collection, you need to select an instance of
the group, and then you can choose "group" in the collection properties editor
to edit this group active collection instead of the view layer one.
* Dupli groups overrides
We can now have multiple instances of the same group with an original "override"
and different overrides depending on the collection the instanced object is part
of.
Technical
=========
* Layers
We use the same api for groups and scene as much as possible.
Reviewers: sergey (depsgraph), mont29 (read/write and user count)
Differential Revision: https://developer.blender.org/D2892
It makes more sense to stick to DEG_iterator_object order in name, since we can
have functions to iterate over different entities and we want all of them to
have common prefix.
We should keep base_flags after CoW object datablock was updated. Not entirely
happy with current solution, but it fixes crash and allows us to run tests
again.
More proper solution would be to make CoW operation a per-component thingie,
which will only update corresponding parts.
There were following issues:
- This was used in a similar way of DEG's ID update callback. No reason to have
yet-another-way of informing editors/engines about changes. Better to keep
regular update mechanism usable and fast for those needs.
- It wasn't granular at all, and granularity in flags is something what we
need to support anyway, even for existing ID update.
- There is no reason to have it per-object. Depsgraph operates on IDs.
- It wasn't clear when and who clears the flag, and was possible to run into
conflicts.
This commit effectively reverts fix T45702 done in 067fe2719a.
Reasoning:
- Blender Internal is being replaced with Eevee, and will be removed entirely
rather soon.
- All render engines are planned to have own depsgraph, so such threading
conflicts should no longer be an issue.
- We don't want to spend time on porting workarounds for EOL things to a new
design. Less code -- faster the work :)
- If such notifications will end up needed for some other cases, we would
need to re-implement this a more proper depsgraph tagging/flushing and make
it to work with all copy-on-write datablocks and everything.
There might be much more logic involved there, also we might not know proper
evaluated CoW pointer there yet. So we leave this to dependency graph to
decide what exactly to do here.
This reverts commit 90ff88646d.
Can not do this yet, if object is not part of graph yet it will not have entry
taq. Need some more generic solution here.
