The main goal here is to rename things in a way that makes sense for
simulation baking, but also for the upcoming bake node.
This also removes some versioning code from 3.6 which initialized the
default bake path. Baked data from back then can't be loaded anymore
anyway, and the way the default path is generated is different now as well.
Pull Request: https://projects.blender.org/blender/blender/pulls/111845
Blob stands for "binary large object" and is a known term. I used to use the term `bdata`
to mean "binary data", mainly because I didn't think of a better name. Blob is a much
better name as it captures the intend of those files much better.
This change breaks existing bakes, because I rename the folder from `bdata` to `blobs`.
I think that is ok, because I also just broke bakes two days ago in a larger refactor
(e92c59bc9b).
Pull Request: https://projects.blender.org/blender/blender/pulls/111822
The hash tables and vector blenlib headers were pulling many more
headers than they actually need, including the C base math header,
our C string API header, and the StringRef header. All of this
potentially slows down compilation and polutes autocomplete
with unrelated information.
Also remove the `ListBase` constructor for `Vector`. It wasn't used
much, and making it easy to use `ListBase` isn't worth it for the
same reasons mentioned above.
It turns out a lot of files depended on indirect includes of
`BLI_string.h` and `BLI_listbase.h`, so those are fixed here.
Pull Request: https://projects.blender.org/blender/blender/pulls/111801
`BKE_simulation_state_serialize.hh` is not necessary anymore,
because the serialization is done at a lower level.
The functionality that lived there in the past is now part of
`BKE_bake_items_serialize.hh`.
Goals of the refactor:
* Internal support for baking individual simulation zones (not exposed in the UI yet).
* More well-defined access to simulation data in geometry nodes. Especially, it
should be more obvious where data is modified. A similar approach should also
work for the Bake node.
Previously, there were a bunch of simulation specific properties in `GeoNodesModifierData`
and then the simulation input and output nodes would have to figure out what to do with that
data. Now, there is a new `GeoNodesSimulationParams` which controls the behavior of
simulation zones. Contrary to before, different simulation zones can now be handled
independently, even if that is not really used yet. `GeoNodesSimulationParams` has to be
subclassed by a user of the geometry nodes API. The subclass controls what each simulation
input and output node does. This some of the logic that was part of the node before, into
the modifier.
The way we store simulation data is "transposed". Previously, we stored zone data per
frame, but now we store frame data per zone. This allows different zones to be more
independent. Consequently, the way the simulation cache is accessed changed. I kept
things simpler for now, avoiding many of the methods we had before, and directly
accessing the data more often which is often simple enough. This change also makes
it theoretically possible to store baked data for separate zones independently.
A downside of this is, that existing baked data can't be read anymore. We don't really
have compatibility guarantees for this format yet, so it's ok. Users will have to bake again.
The bake folder for the modifier now contains an extra subfolder for every zone.
Drawing the cached/baked frames in the timeline is less straight forward now. Currently,
it just draws the state of one of the zones, which usually is identical to that of all other
zones. This will change in the future though, and then the timeline drawing also needs
some new UI work.
Pull Request: https://projects.blender.org/blender/blender/pulls/111623
Listing the "Blender Foundation" as copyright holder implied the Blender
Foundation holds copyright to files which may include work from many
developers.
While keeping copyright on headers makes sense for isolated libraries,
Blender's own code may be refactored or moved between files in a way
that makes the per file copyright holders less meaningful.
Copyright references to the "Blender Foundation" have been replaced with
"Blender Authors", with the exception of `./extern/` since these this
contains libraries which are more isolated, any changed to license
headers there can be handled on a case-by-case basis.
Some directories in `./intern/` have also been excluded:
- `./intern/cycles/` it's own `AUTHORS` file is planned.
- `./intern/opensubdiv/`.
An "AUTHORS" file has been added, using the chromium projects authors
file as a template.
Design task: #110784
Ref !110783.
The `OBJECT_OT_simulation_nodes_cache_delete` operator
would delete the parent bake directory. This could lead to catastrophic
loss of data if the user set their bake directory to a folder that
contains other files or folders.
This commit makes sure that only the "meta" and "bdata" folders get
deleted in the parent directory.
Pull Request: https://projects.blender.org/blender/blender/pulls/110999
The goal is to reuse the same bake items for simulation and normal baking (#110137).
Previously, the bake data was tied to a simulation state which made it harder to reuse.
Now the code for the following things can be reused easily:
- Convert geometry node socket values into bake items and back.
- Serialize and deserialize bake items.
Pull Request: https://projects.blender.org/blender/blender/pulls/110577
String search & replace is a higher level function (unlike BLI_string.h)
which handlers lower level replacements for printing and string copying.
Also use BLI_string_* prefix (matching other utilities).
This makes it possible to use BLI_string in Blender's internal utilities
without depending on DynStr, MemArena... etc.
Modifiers can use the same bake directory now. If multiple modifiers
using conflicting paths are baked at the same time there is now an
error popup.
Modifiers can also bake to directories that already contain data
(including their own). To give users a heads-up there is now a
confirmation popup in that case. It only comes up once per bake operator
invoke to strike a balance between silently overwriting data and not
being too obnoxious when users want to rebake the same simulation many
times.
Pull Request: https://projects.blender.org/blender/blender/pulls/108288
With this the simulation cache pointer is copied over to the evaluated modifier.
This allows the original modifier to be removed without breaking the evaluated
modifier, which results in better decoupling. This can avoid issues when a
non-active depsgraph is evaluated in the background while the user is manipulating
the scene.
Also, it is now assumed that the simulation cache is always allocated even if
there is no simulation (similar to run-time data). This simplifies the code.
Pull Request: https://projects.blender.org/blender/blender/pulls/108976
A lot of files were missing copyright field in the header and
the Blender Foundation contributed to them in a sense of bug
fixing and general maintenance.
This change makes it explicit that those files are at least
partially copyrighted by the Blender Foundation.
Note that this does not make it so the Blender Foundation is
the only holder of the copyright in those files, and developers
who do not have a signed contract with the foundation still
hold the copyright as well.
Another aspect of this change is using SPDX format for the
header. We already used it for the license specification,
and now we state it for the copyright as well, following the
FAQ:
https://reuse.software/faq/
Baking simulations for an object with more than one geonodes modifier
creates cache folders for _all_ modifiers, even if some of them do not
actually have simulation zones. The simulations zones also don't need to
be connected to the output to generate cache folders.
This patch restricts cache folder generation to modifiers which actually
have simulation zones and use them.
Extra cache folders were created because executed modifiers were only
checking if a simulation state exists and not whether it contains actual
zone data (`sim_state->zone_states_.is_empty()`). The modifiers are
always executed if the object is evaluated by the depsgraph, which
happens if _any_ of the modifiers is time-dependent. Time dependency in
turn is enabled if a simulation zone exists in the tree, regardless of
whether it is used.
Checking for zone states in the cache output during baking lets us
decide if a cache folder is needed.
Pull Request: https://projects.blender.org/blender/blender/pulls/108278
This adds `char *simulation_bake_directory` to the nodes modifier. The path is automatically generated the first time the modifier is baked. It is _not_ automatically changed afterwards. The path is relative to the .blend file by default. For now, the path is not exposed in the UI or Python API.
This fixes issues where renaming objects/modifiers can cause the baked data to not work anymore.
Pull Request: https://projects.blender.org/blender/blender/pulls/108201
This adds support for building simulations with geometry nodes. A new
`Simulation Input` and `Simulation Output` node allow maintaining a
simulation state across multiple frames. Together these two nodes form
a `simulation zone` which contains all the nodes that update the simulation
state from one frame to the next.
A new simulation zone can be added via the menu
(`Simulation > Simulation Zone`) or with the node add search.
The simulation state contains a geometry by default. However, it is possible
to add multiple geometry sockets as well as other socket types. Currently,
field inputs are evaluated and stored for the preceding geometry socket in
the order that the sockets are shown. Simulation state items can be added
by linking one of the empty sockets to something else. In the sidebar, there
is a new panel that allows adding, removing and reordering these sockets.
The simulation nodes behave as follows:
* On the first frame, the inputs of the `Simulation Input` node are evaluated
to initialize the simulation state. In later frames these sockets are not
evaluated anymore. The `Delta Time` at the first frame is zero, but the
simulation zone is still evaluated.
* On every next frame, the `Simulation Input` node outputs the simulation
state of the previous frame. Nodes in the simulation zone can edit that
data in arbitrary ways, also taking into account the `Delta Time`. The new
simulation state has to be passed to the `Simulation Output` node where it
is cached and forwarded.
* On a frame that is already cached or baked, the nodes in the simulation
zone are not evaluated, because the `Simulation Output` node can return
the previously cached data directly.
It is not allowed to connect sockets from inside the simulation zone to the
outside without going through the `Simulation Output` node. This is a necessary
restriction to make caching and sub-frame interpolation work. Links can go into
the simulation zone without problems though.
Anonymous attributes are not propagated by the simulation nodes unless they
are explicitly stored in the simulation state. This is unfortunate, but
currently there is no practical and reliable alternative. The core problem
is detecting which anonymous attributes will be required for the simulation
and afterwards. While we can detect this for the current evaluation, we can't
look into the future in time to see what data will be necessary. We intend to
make it easier to explicitly pass data through a simulation in the future,
even if the simulation is in a nested node group.
There is a new `Simulation Nodes` panel in the physics tab in the properties
editor. It allows baking all simulation zones on the selected objects. The
baking options are intentially kept at a minimum for this MVP. More features
for simulation baking as well as baking in general can be expected to be added
separately.
All baked data is stored on disk in a folder next to the .blend file. #106937
describes how baking is implemented in more detail. Volumes can not be baked
yet and materials are lost during baking for now. Packing the baked data into
the .blend file is not yet supported.
The timeline indicates which frames are currently cached, baked or cached but
invalidated by user-changes.
Simulation input and output nodes are internally linked together by their
`bNode.identifier` which stays the same even if the node name changes. They
are generally added and removed together. However, there are still cases where
"dangling" simulation nodes can be created currently. Those generally don't
cause harm, but would be nice to avoid this in more cases in the future.
Co-authored-by: Hans Goudey <h.goudey@me.com>
Co-authored-by: Lukas Tönne <lukas@blender.org>
Pull Request: https://projects.blender.org/blender/blender/pulls/104924
