Was happening when viewport visibility on the particle system is disabled.
This became an issue after c45afcf, but the actual issue goes a bit deeper
and the following aspects were involved:
- Relations builder for particle system was ignoring particle system if
it's visibility is not enabled for viewport. This is something what
shouldn't have been done -- depsgraph relations are supposed to be the
same no matter if it's viewport or render.
- Relation builder was only dealing with duplication set to object, but
was ignoring group duplication.
This is technically a regression in 2.79a-RC as well, so would need to
backport this fix to the branch after extra testing is done here in the
studio.
The new depsgraph was only considering the active action
when attaching relations from the AnimData component/operation
to the properties that are affected by the animation data.
As a result, only properties animated by the active action
were working, while those animated by NLA strips did not change
when playing back/scrubbing the timeline.
This commit fixes this introducing a recursive method to properly
visit all NLA strips, and calling DepsRelBuilder::build_animdata_curves_targets()
on each of those strips.
One thing i'm not fully happy with is all this is_same_* functions. Need to
get rid of this by probably adding explicit entry/init/whatever nodes and
maybe making node criteria aware of whether key will be used as "from" or
as "to" node.
There was a fake cyclic dependency happening when node of node tree is driving
another node of the same tree.
This is related to T53794, but more fixes is needed here.
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
Previously it was done during depsgraph iteration, which is not good at all,
since after evaluation nobody should really modify how object was evaluated.
The RenderResult struct still has a listbase of RenderLayer, but that's ok
since this is strictly for rendering.
* Subversion bump (to 2.80.2)
* DNA low level doversion (renames) - only for .blend created since 2.80 started
Note: We can't use DNA_struct_elem_find or get file version in init_structDNA,
so we are manually iterating over the array of the SDNA elements instead.
Note 2: This doversion change with renames can be reverted in a few months. But
so far it's required for 2.8 files created between October 2016 and now.
Reviewers: campbellbarton, sergey
Differential Revision: https://developer.blender.org/D2927
This is a final step of having proper ownership. Now selecting different
layers in the "top bar" will actually do what this is expected to do.
Surely, there are still things to be done under the hood, that will happen
in a less intrusive way.
Previously tagging particle settings for update will iterate over all objects and
all their particle system to see whether something needs an update or not. Now we
put ParticleSettings as an ID to the dependency graph, so tagging it for update
will nicely flush updates to all dependent particle systems.
Current downside of this is that due to limitation of flush routines it will cause
some extra particle system re-evaluation when it technically not needed, and what's
more annoying currently it will discard point caches more often.
However, this is a good and simple demonstration case to improve tagging/flushing
system to accommodate for such cases (similar issues happens with CoW and shading
components). So let's try to find some generic solution to the problem!
< Dependency graph Copy-on-Write >
--------------------------------
\ ^__^
\ (oo)\_______
(__)\ )\/\
||----w |
|| ||
This is an initial commit of Copy-on-write support added to dependency graph.
Main priority for now: get playback (Alt-A) and all operators (selection,
transform etc) to work with the new concept of clear separation between
evaluated data coming from dependency graph and original data coming from
.blend file (and stored in bmain).
= How does this work? =
The idea is to support Copy-on-Write on the ID level. This means, we duplicate
the whole ID before we cann it's evaluaiton function. This is currently done
in the following way:
- At the depsgraph construction time we create "shallow" copy of the ID
datablock, just so we know it's pointer in memory and can use for function
bindings.
- At the evaluaiton time, the copy of ID get's "expanded" (needs a better
name internally, so it does not conflict with expanding datablocks during
library linking), which means the content of the datablock is being
copied over and all IDs are getting remapped to the copied ones.
Currently we do the whole copy, in the future we will support some tricks
here to prevent duplicating geometry arrays (verts, edges, loops, faces
and polys) when we don't need that.
- Evaluation functions are operating on copied datablocks and never touching
original datablock.
- There are some cases when we need to know non-ID pointers for function
bindings. This mainly applies to scene collections and armatures. The
idea of dealing with this is to "expand" copy-on-write datablock at
the dependency graph build time. This might introduce some slowdown to the
dependency graph construction time, but allows us to have minimal changes
in the code and avoid any hash look-up from evaluation function (one of
the ideas to avoid using pointers as function bindings is to pass name
of layer or a bone to the evaluation function and look up actual data based
on that name).
Currently there is a special function in depsgraph which does such a
synchronization, in the future we might want to make it more generic.
At some point we need to synchronize copy-on-write version of datablock with
the original version. This happens, i.e., when we change active object or
change selection. We don't want any actual evaluation of update flush happening
for such thins, so now we have a special update tag:
DEG_id_tag_update((id, DEG_TAG_COPY_ON_WRITE)
- For the render engines we now have special call for the dependency graph to
give evaluated datablock for the given original one. This isn't fully ideal
but allows to have Cycles viewport render.
This is definitely a subject for further investigation / improvement.
This call will tag copy-on-write component tagged for update without causing
updates to be flushed to any other objects, causing chain reaction of updates.
This tag is handy when selection in the scene changes.
This basically summarizes ideas underneath this commit. The code should be
reasonably documented.
Here is a demo of dependency graph with all copy-on-write stuff in it:
https://developer.blender.org/F635468
= What to expect to (not) work? =
- Only meshes are properly-ish aware of copy-on-write currently, Non-mesh
geometry will probably crash or will not work at all.
- Armatures will need similar depsgraph built-time expansion of the copied
datablock.
- There are some extra tags / relations added, to keep things demo-able but
which are slowing things down for evaluation.
- Edit mode works for until click selection is used (due to the selection
code using EditDerivedMesh created ad-hoc).
- Lots of tools will lack tagging synchronization of copied datablock for
sync with original ID.
= How to move forward? =
There is some tedious work related on going over all the tools, checking
whether they need to work with original or final evaluated object and make
the required changes.
Additionally, there need synchronization tag done in fair amount of tools
and operators as well. For example, currently it's not possible to change
render engine without re-opening the file or forcing dependency graph for
re-build via python console.
There is also now some thoughts required about copying evaluated properties
between objects or from collection to a new object. Perhaps easiest way
would be to move base flag flush to Object ID node and tag new objects for
update instead of doing manual copy.
here is some WIP patch which moves such evaluaiton / flush:
https://developer.blender.org/F635479
Lots of TODOs in the code, with possible optimization.
= How to test? =
This is a feature under heavy development, so obviously it is disabled by
default. The only reason it goes to 2.8 branch is to avoid possible merge
hell.
In order to enable this feature use WITH_DEPSGRAPH_COPY_ON_WRITE CMake
configuration option.
Was rather weird and only used for time source. It is simpler to make depsgraph
to keep track of time source directly.
No need to introduce extra entitites without actual need.
Probes were completely out of depsgraph, so tagging them could not work at all.
For now using some placeholder operations just to ensure order of updates.
