To find all effectors in the scene, we need to loop over all objects.
Doing this during depsgraph evaluation caused crashes because not all
objects are guaranteed to be evaluated yet.
To fix this, we now cache the relations as part of the dependency graph
build. As a bonus this also makes evaluation faster for big scenes,
since looping over all objects for each particle system is slow.
Fixes T55156.
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/
This is something deliver form node type, there is no reason to try cache it
anywhere, especially since it's not used in any performance critical code.
Lighter weight dependency graph is what we want.
The goal is: have id->recalc flags set to components which got changed.
To make it possible for render engines to check on a more granular basis
what changed in the object. For example, is it a transform which changed
or is it just some ID property changed which has nothing to do with rendering.
The tricky part is: we don't want duplicated logic in tagging and flushing.
In order to avoid this duplication, we store ID recalc flag in the component
node type information. That type information could easily be accessed by both
tagging and flushing routines.
Remaining part of the changes are related on changing the way how tagging
works. The new idea here is to have utility function which maps update tag to
a component. This way we can easily set ID recalc flags right away. Without
any duplication of ID recalc flags set in multiple flag handler functions.
With all this being said, there should be no user measurable difference for
now, it's a gigantic basement for some upcoming work and fixes.
The idea is to de-duplicate logic in DEG_id_tag_update() and flushing where we
need to translate depsgraph tag or component type to ID level recalc flag.
Currently unused, but is required for Blender 2.8.
This commit makes it so that only ID components which correspond to the tag
flag are tagged for update (previously the whole ID would have been updated
in the most of cases).
This allows us to have more granular tag flags and prevent tagging of things
we don't want to be tagged.
This is mainly a maintenance commit which was aimed to make work with
this module more pleasant and solve such issues as:
- Annoyance with looong files, which had craftload in them
- Usage of STL for the data structures we've got in BLI
- Possible symbol conflicts
- Not real clear layout of what is located where
So in this commit the following changes are done:
- STL is prohibited, it's not really predictable on various compilers,
with our BLI algorithms we can predict things much better.
There are still few usages of std::vector, but that we'll be
solving later once we've got similar thing in BLI.
- Simplify foreach loops, avoid using const_iterator all over the place.
- New directory layout, which is hopefully easier to follow.
- Some files were split, some of them will be split soon.
The idea of this is to split huge functions into own files with
good documentation and everything.
- Removed stuff which was planned for use in the future but was never
finished, tested or anything.
Let's wipe it out for now, and bring back once we really start using
it, so it'll be more clear if it solves our needs.
- All the internal routines were moved to DEG namespace to separate
them better from rest of blender.
Some places now annoyingly using DEG::foo, but that we can olve by
moving some utility functions inside of the namespace.
While working on this we've found some hotspot in updates flush, so
now playback of blenrig is few percent faster (something like 96fps
with previous master and around 99-100fps after this change).
Not saying it's something final, there is still room for cleanup and
API simplification, but those might happen as a regular development
now without doing any global changes.
This commit integrates the work done so far on the new dependency graph system,
where goal was to replace legacy depsgraph with the new one, supporting loads of
neat features like:
- More granular dependency relation nature, which solves issues with fake cycles
in the dependencies.
- Move towards all-animatable, by better integration of drivers into the system.
- Lay down some basis for upcoming copy-on-write, overrides and so on.
The new system is living side-by-side with the previous one and disabled by
default, so nothing will become suddenly broken. The way to enable new depsgraph
is to pass `--new-depsgraph` command line argument.
It's a bit early to consider the system production-ready, there are some TODOs
and issues were discovered during the merge period, they'll be addressed ASAP.
But it's important to merge, because it's the only way to attract artists to
really start testing this system.
There are number of assorted documents related on the design of the new system:
* http://wiki.blender.org/index.php/User:Aligorith/GSoC2013_Depsgraph#Design_Documents
* http://wiki.blender.org/index.php/User:Nazg-gul/DependencyGraph
There are also some user-related information online:
* http://code.blender.org/2015/02/blender-dependency-graph-branch-for-users/
* http://code.blender.org/2015/03/more-dependency-graph-tricks/
Kudos to everyone who was involved into the project:
- Joshua "Aligorith" Leung -- design specification, initial code
- Lukas "lukas_t" Toenne -- integrating code into blender, with further fixes
- Sergey "Sergey" "Sharybin" -- some mocking around, trying to wrap up the
project and so
- Bassam "slikdigit" Kurdali -- stressing the new system, reporting all the
issues and recording/writing documentation.
- Everyone else who i forgot to mention here :)
