When "Relative Remap" option was added, the intention was only to remap
paths that were already relative. However it remapped all paths.
This was reported as T62612 and fixed recently,
however some Python script authors depended on the old behavior.
For users, it's reasonable to use the existing operators to make paths
absolute/relative. For scripts however it's useful to be able to write
out individual data-blocks with the ability to make all paths relative.
Now `bpy.data.libraries.write()` takes a path_remap argument which can
be `NONE/RELATIVE/RELATIVE_ALL/ABSOLUTE` allowing the script author to
choose how paths are handled when writing out data-blocks.
Addresses T77768.
Prelimenary step to fix T77460.
Not sure how or when that thing was done, but since that call walks
around collections relationships, it's an utterly critical violation of
liblinking principles (code here should never, ever 'get outside' of its
own ID scope).
This was wroking so far only because code called through this function
(`BKE_collection_parent_relations_rebuild`) was only following parents
pointers (in `BKE_collection_find_cycle()`), which would be either valid
or non-existent.
But next commit is going to change that to also check collection's
objects instancing of other collections.
When a fluid is put under influence of gravity or acceleration, it
forms an internal pressure gradient, which causes observable effects
like buoyancy. Since now cloth has support for simulating pressure
changes caused by fluid compression or expansion, it makes sense to
also support the effects of gravity.
This is intended for better simulation of objects filled or
surrounded by fluids, especially when constrained by collisions
or pinned vertices, and should result in more realistic shapes.
Obviously, this doesn't actually simulate fluid dynamics; instead
it is assumed that the fluid immediately adapts to changes in the
shape or acceleration of the object without friction or turbulence,
and instantly reaches a new static equilibrium.
Differential Revision: https://developer.blender.org/D6442
The current particle state is stored in a `CustomData` instance and
the cache is stored in `PointCache`.
The current state exists on the copy-on-write copies of the simulation,
while the cache only exists in the original data block.
This patch implements a temporary trivial particle simulation that does not
use the node system yet. It is used for testing and will be replaced soon.
`PointCache` still has some limitations that need to be overcome using
separate refactorings. For example, we need to be able to store the number
of particles in the point cache. Also we need to change which attributes
are stored for a particle system more dynamically than is currently possible afaik.
Reviewers: brecht
Differential Revision: https://developer.blender.org/D7836
This is a critical fix that should also be backported to 2.83.1
Fairly stupid bug in fact, code detecting changes across undo steps was
assuming that each BHEAD (a block of data in blendfiles) would not be larger
than one memory chunk... Which is the case in alsmost every situation,
besides some super-heavy geometries, and other similar things (images
would also be affected e.g.).
