Check was misc-const-correctness, combined with readability-isolate-declaration
as suggested by the docs.
Temporarily clang-format "QualifierAlignment: Left" was used to get consistency
with the prevailing order of keywords.
Pull Request: https://projects.blender.org/blender/blender/pulls/132361
* Use .empty() and .data()
* Use nullptr instead of 0
* No else after return
* Simple class member initialization
* Add override for virtual methods
* Include C++ instead of C headers
* Remove some unused includes
* Use default constructors
* Always use braces
* Consistent names in definition and declaration
* Change typedef to using
Pull Request: https://projects.blender.org/blender/blender/pulls/132361
The issue was that cycles did not take ownership of the entire `VolumeGridData`.
The `VolumeTreeAccessToken` that was used already only makes sure that the
grid is not unloaded when it was read from disk for example. It does not extend
the lifetime of the `VolumeGridData` as a whole.
There was one functional issue with the previous API which was its
use in `VolumeGrid<T>::grid_for_write(tree_token)`. The issue was
that the tree token had to be received before the grid is accessed.
However, this `grid_for_write` method might create a copy of the
`VolumeGridData` internally and if it does, the passed in `tree_token`
corresponds to the wrong tree.
The solution is to output the token as part of the method. This has two
additional benefits:
* The API is more safe, because one can't pass an r-value into the methods
anymore. This generally shouldn't be done, because the token should
live at least as long as the OpenVDB tree is used and shouldn't be freed
immediatly.
* The API is a bit simpler, because it's not necessary to call the
`VolumeGrid.tree_access_token()` method anymore.
This refactors how volume grids are stored with the following new goals in mind:
* Get a **stand-alone volume grid** data structure that can be used by geometry nodes.
Previously, the `VolumeGrid` data structure was tightly coupled with the `Volume` data block.
* Support **implicit sharing of grids and trees**. Previously, it was possible to share data
when multiple `Volume` data blocks loaded grids from the same `.vdb` files but this was
not flexible enough.
* Get a safe API for **lazy-loading and unloading** of grids without requiring explicit calls
to some "load" function all the time.
* Get a safe API for **caching grids from files** that is not coupled to the `Volume` data block.
* Get a **tiered API** for different levels of `openvdb` involvement:
* No `OpenVDB`: Since `WITH_OPENVDB` is optional, it's helpful to have parts of the API that
still work in this case. This makes it possible to write high level code for volumes that does
not require `#ifdef WITH_OPENVDB` checks everywhere. This is in `BKE_volume_grid_fwd.hh`.
* Shallow `OpenVDB`: Code using this API requires `WITH_OPENVDB` checks. However, care
is taken to not include the expensive parts of `OpenVDB` and to use forward declarations as
much as possible. This is in `BKE_volume_grid.hh` and uses `openvdb_fwd.hh`.
* "Full" `OpenVDB`: This API requires more heavy `OpenVDB` includes. Fortunately, it turned
out to be not necessary for the common API. So this is only used for task specific APIs.
At the core of the new API is the `VolumeGridData` type. It's a wrapper around an
`openvdb::Grid` and adds some features on top like implicit sharing, lazy-loading and unloading.
Then there are `GVolumeGrid` and `VolumeGrid` which are containers for a volume grid.
Semantically, each `VolumeGrid` has its own independent grid, but this is cheap due to implicit
sharing. At highest level we currently have the `Volume` data-block which contains a list of
`VolumeGrid`.
```mermaid
flowchart LR
Volume --> VolumeGrid --> VolumeGridData --> openvdb::Grid
```
The loading of `.vdb` files is abstracted away behind the volume file cache API. This API makes
it easy to load and reuse entire files and individual grids from disk. It also supports caching
simplify levels for grids on disk.
An important new concept are the "tree access tokens". Whenever some code wants to work
with an openvdb tree, it has to retrieve an access token from the corresponding `VolumeGridData`.
This access token has to be kept alive for as long as the code works with the grid data. The same
token is valid for read and write access. The purpose of these access tokens is to make it possible
to detect when some code is currently working with the openvdb tree. This allows freeing it if it's
possible to reload it later on (e.g. from disk). It's possible to free a tree that is referenced by
multiple owners, but only no one is actively working with. In some sense, this is similar to the
existing `ImageUser` concept.
The most important new files to read are `BKE_volume_grid.hh` and `BKE_volume_grid_file_cache.hh`.
Most other changes are updates to existing code to use the new API.
Pull Request: https://projects.blender.org/blender/blender/pulls/116315
Since 34b4487844, attributes are always made mutable when
accessed from the RNA API. This can result in unnecessary copies, which
increases memory usage and reduces performance.
Cycles is the only user of the C++ RNA API, which we'd like to remove
in the future since it doesn't really make sense in the big picture.
Hydra is now a better alternative for external render engines.
To start that change and fix the unnecessary copies, this commit
moves to use Blender headers directly for accessing attribute and
other geometry data. This also removes the few places that still had
overhead from the RNA API after the changes ([0]) in 3.6. In a simple
test with a large grid, I observed a 1.76x performance improvement,
from 1.04 to 0.59 seconds to extract the mesh data to Cycles.
[0]: https://wiki.blender.org/wiki/Reference/Release_Notes/3.6/Cycles#Performance
Pull Request: https://projects.blender.org/blender/blender/pulls/112306
This patch makes it possible to change the precision with which to
store volume data in the NanoVDB data structure (as float, half, or
using variable bit quantization) via the previously unused precision
field in the volume data block.
It makes it possible to further reduce memory usage during
rendering, at a slight cost to the visual detail of a volume.
Differential Revision: https://developer.blender.org/D10023
This adds support for rendering motion blur for volumes, using their
velocity field. This works for fluid simulations and imported VDB
volumes. For the latter, the name of the velocity field can be set per
volume object, with automatic detection of velocity fields that are
split into 3 scalar grids.
A new parameter is also added to scale velocity for more artistic control.
Like for Alembic and USD caches, a parameter to set the unit of time in
which the velocity vectors are expressed is also added. For Blender gas
simulations, the velocity unit should always be in seconds, so this is
only exposed for volume objects which may come from external OpenVDB
files.
These parameters are available under the `Render` panels for the fluid
domain and the volume object data properties respectively.
Credits: kernel advection code from Tangent Animation's Blackbird based
on earlier work by Geraldine Chua
Differential Revision: https://developer.blender.org/D14629
* Replace license text in headers with SPDX identifiers.
* Remove specific license info from outdated readme.txt, instead leave details
to the source files.
* Add list of SPDX license identifiers used, and corresponding license texts.
* Update copyright dates while we're at it.
Ref D14069, T95597
Remove prefix of filenames that is the same as the folder name. This used
to help when #includes were using individual files, but now they are always
relative to the cycles root directory and so the prefixes are redundant.
For patches and branches, git merge and rebase should be able to detect the
renames and move over code to the right file.
