That feature will not be ready (or at least, not tested enough) to be
officially part of 2.80 beta. So we disable it by default, hidding it
behind a startup option (`--enable-static-override`), and a python
app var (`bpy.app.use_static_override`).
That way, people who really want to play with it can do it easily, while
not exposing/enabling non-production-ready feature by default.
Note that underlying override code remains active, i.e. files we do have
overridden data-blocks will be loaded correctly according to static override.
Again, we cannot actually get rid of G_MAIN global access here, so in
most case just 'marked' them as valid, and added assert checks to ensure
we do only work with IDs in G_MAIN in those cases.
* depsgraph.ids: all evaluated datablocks in the depsgraph
* depsgraph.objects: all evaluated objects in the depsgraph
* depsgraph.object_instances: all object instances to display or render
* depsgraph.updates: list of updates to datablocks
This introduces a new depsgraph API for getting updated datablocks,
rather than getting it from bpy.data.
* depsgraph.ids_updated gives a list of all datablocks in the depsgraph
which have been updated.
* depsgraph.id_type_updated('TYPE') is true if any datablock of the given
type has been added, removed or modified.
More API updates are coming to properly handle multiple depsgraphs and
finer update granularity, but this should make Cycles work again.
OVERVIEW
* In 2.7 terminology, all layers and groups are now collection datablocks.
* These collections are nestable, linkable, instanceable, overrideable, ..
which opens up new ways to set up scenes and link + override data.
* Viewport/render visibility and selectability are now a part of the collection
and shared across all view layers and linkable.
* View layers define which subset of the scene collection hierarchy is excluded
for each. For many workflows one view layer can be used, these are more of an
advanced feature now.
OUTLINER
* The outliner now has a "View Layer" display mode instead of "Collections",
which can display the collections and/or objects in the view layer.
* In this display mode, collections can be excluded with the right click menu.
These will then be greyed out and their objects will be excluded.
* To view collections not linked to any scene, the "Blender File" display mode
can be used, with the new filtering option to just see Colleciton datablocks.
* The outliner right click menus for collections and objects were reorganized.
* Drag and drop still needs to be improved. Like before, dragging the icon or
text gives different results, we'll unify this later.
LINKING AND OVERRIDES
* Collections can now be linked into the scene without creating an instance,
with the link/append operator or from the collections view in the outliner.
* Collections can get static overrides with the right click menu in the outliner,
but this is rather unreliable and not clearly communicated at the moment.
* We still need to improve the make override operator to turn collection instances
into collections with overrides directly in the scene.
PERFORMANCE
* We tried to make performance not worse than before and improve it in some
cases. The main thing that's still a bit slower is multiple scenes, we have to
change the layer syncing to only updated affected scenes.
* Collections keep a list of their parent collections for faster incremental
updates in syncing and caching.
* View layer bases are now in a object -> base hash to avoid quadratic time
lookups internally and in API functions like visible_get().
VERSIONING
* Compatibility with 2.7 files should be improved due to the new visibility
controls. Of course users may not want to set up their scenes differently
now to avoid having separate layers and groups.
* Compatibility with 2.8 is mostly there, and was tested on Eevee demo and Hero
files. There's a few things which are know to be not quite compatible, like
nested layer collections inside groups.
* The versioning code for 2.8 files is quite complicated, and isolated behind
#ifdef so it can be removed at the end of the release cycle.
KNOWN ISSUES
* The G-key group operators in the 3D viewport were left mostly as is, they
need to be modified still to fit better.
* Same for the groups panel in the object properties. This needs to be updated
still, or perhaps replaced by something better.
* Collections must all have a unique name. Less restrictive namespacing is to
be done later, we'll have to see how important this is as all objects within
the collections must also have a unique name anyway.
* Full scene copy and delete scene are exactly doing the right thing yet.
Differential Revision: https://developer.blender.org/D3383https://code.blender.org/2018/05/collections-and-groups/
The MovieSequence and MovieClip classes now have a metadata() function
that exposes the `IDProperty *` holding the video metadata.
Part of: https://developer.blender.org/D2273
Reviewed by: @campbellbarton
This simplifies remapping task, since you don't have to ensure your
overrides are created in the correct dependency order.
Uses famous LIB_TAG_DOIT to mark IDs to be overridden.
Currently this is a no-visible-changes change, but the idea is to use this
dedicated flag to tell which exact components of ID changed, make it more
granular than just OBJECT and OBJECT_DATA. Allow setting this field based
on what components new dependency graph flushed on evaluation.
Avoid creating new Python instances
every time a scene, object, mesh .. etc are accessed.
Also resolves crashes T28724, T53530
although it's only valid for ID types, not modifiers vertices etc.
Back-ported from blender2.8 branch.
This is essentially a huge refactor/extension of our existing RNA
compare & copy code, since static override needs more advanced handling here.
Note that not all new features are implemented yet, advanced things like
collections insertion/deletion are still TODO (medium priority).
This completes the ground work for overrides, remaining commits will be
about UI and some basic/testing activation of overrides for a limited
set of data-blocks & properties.
For details see https://developer.blender.org/D2417
