The default import method for an asset library can now be determined in
the Preferences. The Asset Browser has a new "Follow Preferences" option
for the importing. The essentials asset library still only uses "Append
(Reuse Data)".
This is part of #104686, which aims at improving the import method
selection, especially for the introduction of the new essentials library
(which doesn't support certain import methods). Further changes are
coming to improve the UI, see #104686.
Pull Request: #104688
Adds a new built-in asset library that contains all other asset
libraries visible in the asset library selector menu. This also means
all their asset catalogs will be displayed as a single merged tree. The
asset catalogs are not editable, since this would require support for
writing multiple catalog definition files, which isn't there yet.
Often it's not relevant where an asset comes from. Users just want to be
able to get an asset quickly, comparable to how people use a search
engine to browse images or the web itself, instead of first going to a
dedicated platform. They don't want to bother with first choosing where
they want the result to come from.
This especially is needed for the Asset Shelf (T102879) that is being
developed for the brush assets project (T101895). With this, users will
have access to all their brushes efficiently from the 3D view, without
much browsing.
Did an informal review of the asset system bits with Sybren.
No user visible changes expected.
If an asset library is located on disk, store the path to it in the
asset library data. This is called the "root path" now.
With this we can construct an asset identifier, which is introduced in
the following commit.
A `using FooPtr = std::unique_ptr<Foo>` isn't that useful usually, just
saves a few character stokes. It obfuscates the underlying type, which
is usually relevant information. Plus, `Ptr` for a unique pointer is
misleading (should be `UPtr` or similar).
Move "using" declarations and member variables to the top of the class.
See https://wiki.blender.org/wiki/Style_Guide/C_Cpp#Class_Layout.
Changes access specifiers of some variables from public/protected to
private, there was no point in not having them private.
Adds a new `source/blender/asset_system` directory and moves asset
related files from BKE to it. More asset related code can follow
(e.g. asset indexing, ED_assetlist stuff) but needs further work to
untangle it. I also kept `BKE_asset.h` and `asset.cc` as is, since they
deal with asset DNA data mostly, thus make sense in BKE.
Motivation:
- Makes the asset system design more present (term wasn't even used in
code before).
- An `asset_system` directory is quite descriptive (trivial to identify
core asset system features) and makes it easy to find asset code.
- Asset system is mostly runtime data, with little relation to other
`Main`/BKE/DNA types.
- There's a lot of stuff in BKE already. It shouldn't be just a dump for
all stuff that seems core enough.
- Being its own directly helps us be more mindful about encapsulating
the module well, and avoiding dependencies on other modules.
- We can be more free with splitting files here than in BKE.
- In future there might be an asset system BPY module, which would then
map quite nicely to the `asset_system` directory.
Checked with some other core devs, consensus seems that this makes
sense.
