Previously, the attribute accessor were defined in the `geometry_component_*.cc`
files. This made sense back in the day, because this attribute API was only used
through `GeometryComponent`. However, nowadays this attribute API is independent
of `GeometryComponent`. E.g. one can use `mesh.attributes()` without ever
creating a component.
The refactor contains the following changes:
* Move attribute accessors to separate files for each geometry type. E.g. from
`geometry_component_mesh.cc` to `mesh_attributes.cc`.
* Move implementations of e.g. `Mesh::attributes()` to `mesh.cc`.
* Provide access to the `AttributeAccessorFunctions` without actually having a
geometry. This will be useful to e.g. implement
`attribute_is_builtin_on_component_type` without dummy components.
Pull Request: https://projects.blender.org/blender/blender/pulls/130516
We often have the situation where it would be good if we could easily estimate
the memory usage of some value (e.g. a mesh, or volume). Examples of where we
ran into this in the past:
* Undo step size.
* Caching of volume grids.
* Caching of loaded geometries for import geometry nodes.
Generally, most caching systems would benefit from the ability to know how much
memory they currently use to make better decisions about which data to free and
when. The goal of this patch is to introduce a simple general API to count the
memory usage that is independent of any specific caching system. I'm doing this
to "fix" the chicken and egg problem that caches need to know the memory usage,
but we don't really need to count the memory usage without using it for caches.
Implementing caching and memory counting at the same time make both harder than
implementing them one after another.
The main difficulty with counting memory usage is that some memory may be shared
using implicit sharing. We want to avoid double counting such memory. How
exactly shared memory is treated depends a bit on the use case, so no specific
assumptions are made about that in the API. The gathered memory usage is not
expected to be exact. It's expected to be a decent approximation. It's neither a
lower nor an upper bound unless specified by some specific type. Cache systems
generally build on top of heuristics to decide when to free what anyway.
There are two sides to this API:
1. Get the amount of memory used by one or more values. This side is used by
caching systems and/or systems that want to present the used memory to the
user.
2. Tell the caller how much memory is used. This side is used by all kinds of
types that can report their memory usage such as meshes.
```cpp
/* Get how much memory is used by two meshes together. */
MemoryCounter memory;
mesh_a->count_memory(memory);
mesh_b->count_memory(memory);
int64_t bytes_used = memory.counted_bytes();
/* Tell the caller how much memory is used. */
void Mesh::count_memory(blender::MemoryCounter &memory) const
{
memory.add_shared(this->runtime->face_offsets_sharing_info,
this->face_offsets().size_in_bytes());
/* Forward memory counting to lower level types. This should be fairly common. */
CustomData_count_memory(this->vert_data, this->verts_num, memory);
}
void CustomData_count_memory(const CustomData &data,
const int totelem,
blender::MemoryCounter &memory)
{
for (const CustomDataLayer &layer : Span{data.layers, data.totlayer}) {
memory.add_shared(layer.sharing_info, [&](blender::MemoryCounter &shared_memory) {
/* Not quite correct for all types, but this is only a rough approximation anyway. */
const int64_t elem_size = CustomData_get_elem_size(&layer);
shared_memory.add(totelem * elem_size);
});
}
}
```
Pull Request: https://projects.blender.org/blender/blender/pulls/126295
This was necessary when attributes were stored embedded in legacy
structs like `MPoly`. Nowadays that isn't the case anymore, and there
doesn't seem to be a reason to restrict the creation of attributes.
All builtin attributes are now stored as named attributes, so the old
code path from where they were stored with non-generic types can be
removed. The stored type and attribute type don't have to be tracked
separately anymore either.
Each value is now out of the global namespace, so they can be shorter
and easier to read. Most of this commit just adds the necessary casting
and namespace specification. `enum class` can be forward declared since
it has a specified size. We will make use of that in the next commit.
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.
Remove the "_for_read" suffix from methods to get geometry and geometry
components. That should be considered the default, so the suffix just
adds unnecessary text. This is consistent with the attribute API and
various implicit sharing data access methods.
Use "from_mesh" instead of "create_with_mesh". This is consistent with
the recently used naming for the `IndexMask` API.
Pull Request: https://projects.blender.org/blender/blender/pulls/110738
Move `GeometrySet` and `GeometryComponent` and subclasses
to the `blender::bke` namespace. This wasn't done earlier since
these were one of the first C++ classes used throughout Blender,
but now it is common.
Also remove the now-unnecessary C-header, since all users of
the geometry set header are now in C++.
Pull Request: https://projects.blender.org/blender/blender/pulls/109020
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/
The main goal of these changes is to support checking if some data has
been changed over time. This is used by the WIP simulation nodes during
baking to detect which attributes have to be stored in every frame because
they have changed.
By using a combination of a weak user count and a version counter, it is
possible to detect that an attribute (or any data controlled by implicit
sharing) has not been changed with O(1) memory and time. It's still
possible that the data has been changed multiple times and is the same
in the end and beginning of course. That wouldn't be detected using this
mechanism.
The `ImplicitSharingInfo` struct has a new weak user count. A weak
reference is one that does not keep the referenced data alive, but makes sure
that the `ImplicitSharingInfo` itself is not deleted. If some piece of
data has one strong and multiple weak users, it is still mutable. If the
strong user count goes down to zero, the referenced data is freed.
Remaining weak users can check for this condition using `is_expired`.
This is a bit similar to `std::weak_ptr` but there is an important difference:
a weak user can not become a strong user while one can create a `shared_ptr`
from a `weak_ptr`. This restriction is necessary, because some code might
be changing the referenced data assuming that it is the only owner. If
another thread suddenly adds a new owner, the data would be shared again
and the first thread would not have been allowed to modify the data in
the first place.
There is also a new integer version counter in `ImplicitSharingInfo`.
It is incremented whenever some code wants to modify the referenced data.
Obviously, this can only be done when the data is not shared because then
it would be immutable. By comparing an old and new version number of the
same sharing info, one can check if the data has been modified. One has
to keep a weak reference to the sharing info together with the old version
number to ensure that the new sharing info is still the same as the old one.
Without this, it can happen that the sharing info was freed and a new
one was allocated at the same pointer address. Using a strong reference
for this purpose does not work, because then the data would never be
modified because it's shared.
Implicit sharing means attribute ownership is shared between geometry
data-blocks, and the sharing happens automatically. So it's unnecessary
to choose whether to enable it when copying a mesh.
Add the ability to retrieve implicit sharing info directly from the
C++ attribute API, which simplifies memory usage and performance
optimizations making use of it. This commit uses the additions to
the API to avoid copies in a few places:
- The "rest_position" attribute in the mesh modifier stack
- Instance on Points node
- Instances to points node
- Mesh to points node
- Points to vertices node
Many files are affected because in order to include the new information
in the API's returned data, I had to switch a bunch of types from
`VArray` to `AttributeReader`. This generally makes sense anyway, since
it allows retrieving the domain, which wasn't possible before in some
cases. I overloaded the `*` deference operator for some syntactic sugar
to avoid the (very ugly) `.varray` that would be necessary otherwise.
Pull Request: https://projects.blender.org/blender/blender/pulls/107059
We don't use the callbacks that create virtual arrays from the custom data
anymore, they just add extra indirection. The only non-obvious case was
the crease attribute which had a setter function. Replace that with an
attribute validator like the other similar attributes.
Pull Request: https://projects.blender.org/blender/blender/pulls/107088
For example
```
OIIOOutputDriver::~OIIOOutputDriver()
{
}
```
becomes
```
OIIOOutputDriver::~OIIOOutputDriver() {}
```
Saves quite some vertical space, which is especially handy for
constructors.
Pull Request: https://projects.blender.org/blender/blender/pulls/105594
This reverts commit 19222627c6.
Something went wrong here, seems like this commit merged the main branch
into the release branch, which should never be done.
This reverts commit 68181c2560.
I merged 3.6 into 3.5 by mistake. Basically I had a PR against main,
then changed it in the last minute to be against 3.5 via the
web-interface unaware that I shouldn't do it without updating the
patch.
Original Pull Request: #104889
Note that the node group has its sockets names
translated, while the built-in nodes don't.
So we need to use data_ for the built-in nodes names,
and the sockets of the created node groups.
Pull Request #104889
Bounding box calculation can be a large in some situations, especially
instancing. This patch caches the min and max of the bounding box in
runtime data of meshes, point clouds, and curves, implementing part of
T96968.
Bounds are now calculated lazily-- only after they are tagged dirty.
Also, cached bounds are also shared when copying geometry data-blocks
that have equivalent data. When bounds are calculated on an evaluated
data-block, they are also accessible on the original, and the next
evaluated ID will also share them. A geometry will stop sharing bounds
as soon as its positions (or radii) are changed.
Just caching the bounds gave a 2-3x speedup with thousands of mesh
geometry instances in the viewport. Sharing the bounds can eliminate
recalculations entirely in cases like copying meshes in geometry nodes
or the selection paint brush in curves sculpt mode, which causes a
reevaluation but doesn't change the positions.
**Implementation**
The sharing is achieved with a `shared_ptr` that points to a cache mutex
(from D16419) and the cached bounds data. When geometries are copied,
the bounds are shared by default, and only "un-shared" when the bounds
are tagged dirty.
Point clouds have a new runtime struct to store this data. Functions
for tagging the data dirty are improved for added for point clouds
and improved for curves. A missing tag has also been fixed for mesh
sculpt mode.
**Future**
There are further improvements which can be worked on next
- Apply changes to volume objects and other types where it makes sense
- Continue cleanup changes described in T96968
- Apply shared cache design to more expensive data like triangulation
or normals
Differential Revision: https://developer.blender.org/D16204
This is the conventional way of dealing with unused arguments in C++,
since it works on all compilers.
Regex find and replace: `UNUSED\((\w+)\)` -> `/*$1*/`
Replace `mesh_attributes`, `mesh_attributes_for_write` and the point
cloud versions with methods on the `Mesh` and `PointCloud` types.
This makes them friendlier to use and improves readability.
Differential Revision: https://developer.blender.org/D15907
A geometry component may reference read-only geometry.
In this case it has to be copied before making changes to it.
This was caused by rBb876ce2a4a4638142.
Currently, there are two attribute API. The first, defined in `BKE_attribute.h` is
accessible from RNA and C code. The second is implemented with `GeometryComponent`
and is only accessible in C++ code. The second is widely used, but only being
accessible through the `GeometrySet` API makes it awkward to use, and even impossible
for types that don't correspond directly to a geometry component like `CurvesGeometry`.
This patch adds a new attribute API, designed to replace the `GeometryComponent`
attribute API now, and to eventually replace or be the basis of the other one.
The basic idea is that there is an `AttributeAccessor` class that allows code to
interact with a set of attributes owned by some geometry. The accessor itself has
no ownership. `AttributeAccessor` is a simple type that can be passed around by
value. That makes it easy to return it from functions and to store it in containers.
For const-correctness, there is also a `MutableAttributeAccessor` that allows
changing individual and can add or remove attributes.
Currently, `AttributeAccessor` is composed of two pointers. The first is a pointer
to the owner of the attribute data. The second is a pointer to a struct with
function pointers, that is similar to a virtual function table. The functions
know how to access attributes on the owner.
The actual attribute access for geometries is still implemented with the `AttributeProvider`
pattern, which makes it easy to support different sources of attributes on a
geometry and simplifies dealing with built-in attributes.
There are different ways to get an attribute accessor for a geometry:
* `GeometryComponent.attributes()`
* `CurvesGeometry.attributes()`
* `bke::mesh_attributes(const Mesh &)`
* `bke::pointcloud_attributes(const PointCloud &)`
All of these also have a `_for_write` variant that returns a `MutabelAttributeAccessor`.
Differential Revision: https://developer.blender.org/D15280
Use a shorter/simpler license convention, stops the header taking so
much space.
Follow the SPDX license specification: https://spdx.org/licenses
- C/C++/objc/objc++
- Python
- Shell Scripts
- CMake, GNUmakefile
While most of the source tree has been included
- `./extern/` was left out.
- `./intern/cycles` & `./intern/atomic` are also excluded because they
use different header conventions.
doc/license/SPDX-license-identifiers.txt has been added to list SPDX all
used identifiers.
See P2788 for the script that automated these edits.
Reviewed By: brecht, mont29, sergey
Ref D14069
- Added space below non doc-string comments to make it clear
these aren't comments for the symbols directly below them.
- Use doxy sections for some headers.
- Minor improvements to doc-strings.
Ref T92709
Goals of this refactor:
* Simplify creating virtual arrays.
* Simplify passing virtual arrays around.
* Simplify converting between typed and generic virtual arrays.
* Reduce memory allocations.
As a quick reminder, a virtual arrays is a data structure that behaves like an
array (i.e. it can be accessed using an index). However, it may not actually
be stored as array internally. The two most important implementations
of virtual arrays are those that correspond to an actual plain array and those
that have the same value for every index. However, many more
implementations exist for various reasons (interfacing with legacy attributes,
unified iterator over all points in multiple splines, ...).
With this refactor the core types (`VArray`, `GVArray`, `VMutableArray` and
`GVMutableArray`) can be used like "normal values". They typically live
on the stack. Before, they were usually inside a `std::unique_ptr`. This makes
passing them around much easier. Creation of new virtual arrays is also
much simpler now due to some constructors. Memory allocations are
reduced by making use of small object optimization inside the core types.
Previously, `VArray` was a class with virtual methods that had to be overridden
to change the behavior of a the virtual array. Now,`VArray` has a fixed size
and has no virtual methods. Instead it contains a `VArrayImpl` that is
similar to the old `VArray`. `VArrayImpl` should rarely ever be used directly,
unless a new virtual array implementation is added.
To support the small object optimization for many `VArrayImpl` classes,
a new `blender::Any` type is added. It is similar to `std::any` with two
additional features. It has an adjustable inline buffer size and alignment.
The inline buffer size of `std::any` can't be relied on and is usually too
small for our use case here. Furthermore, `blender::Any` can store
additional user-defined type information without increasing the
stack size.
Differential Revision: https://developer.blender.org/D12986
In order to address feedback that the "Stable ID" was not easy enough
to use, remove the "Stable ID" output from the distribution node and
the input from the instance on points node. Instead, the nodes write
or read a builtin named attribute called `id`. In the future we may
add more attributes like `edge_id` and `face_id`.
The downside is that more behavior is invisible, which is les
expected now that most attributes are passed around with node links.
This behavior will have to be explained in the manual.
The random value node's "ID" input that had an implicit index input
is converted to a special implicit input that uses the `id` attribute
if possible, but otherwise defaults to the index. There is no way to
tell in the UI which it uses, except by knowing that rule and checking
in the spreadsheet for the id attribute.
Because it isn't always possible to create stable randomness, this
attribute does not always exist, and it will be possible to remove it
when we have the attribute remove node back, to improve performance.
Differential Revision: https://developer.blender.org/D12903
A virtual array is a data structure that is similar to a normal array
in that its elements can be accessed by an index. However, a virtual
array does not have to be a contiguous array internally. Instead, its
elements can be layed out arbitrarily while element access happens
through a virtual function call. However, the virtual array data
structures are designed so that the virtual function call can be avoided
in cases where it could become a bottleneck.
Most commonly, a virtual array is backed by an actual array/span or
is a single value internally, that is the same for every index.
Besides those, there are many more specialized virtual arrays like the
ones that provides vertex positions based on the `MVert` struct or
vertex group weights.
Not all attributes used by geometry nodes are stored in simple contiguous
arrays. To provide uniform access to all kinds of attributes, the attribute
API has to provide virtual array functionality that hides the implementation
details of attributes.
Before this refactor, the attribute API provided its own virtual array
implementation as part of the `ReadAttribute` and `WriteAttribute` types.
That resulted in unnecessary code duplication with the virtual array system.
Even worse, it bound many algorithms used by geometry nodes to the specifics
of the attribute API, even though they could also use different data sources
(such as data from sockets, default values, later results of expressions, ...).
This refactor removes the `ReadAttribute` and `WriteAttribute` types and
replaces them with `GVArray` and `GVMutableArray` respectively. The `GV`
stands for "generic virtual". The "generic" means that the data type contained
in those virtual arrays is only known at run-time. There are the corresponding
statically typed types `VArray<T>` and `VMutableArray<T>` as well.
No regressions are expected from this refactor. It does come with one
improvement for users. The attribute API can convert the data type
on write now. This is especially useful when writing to builtin attributes
like `material_index` with e.g. the Attribute Math node (which usually
just writes to float attributes, while `material_index` is an integer attribute).
Differential Revision: https://developer.blender.org/D10994
Previously, the spreadsheet editor could only show data of the original
and of the final evaluated object. Now it is possible to show the data
at some intermediate stages too.
For that the mode has to be set to "Node" in the spreadsheet editor.
Furthermore, the preview of a specific node has to be activated by
clicking the new icon in the header of geometry nodes.
The exact ui of this feature might be refined in upcoming commits.
It is already very useful for debugging node groups in it's current
state though.
Differential Revision: https://developer.blender.org/D10875
After further thought, the implementation of the "normal" attribute
from D10541 is not the best approach to expose this data, mainly
because it blindly copied existing design rather than using the
best method in the context of the generalized attribute system.
In Blender, vertex normals are simply a cache of the average normals
from the surrounding / connected faces. Because we have automatic
interpolation between domains already, we don't need a special
`vertex_normal` attribute for this case, we can just let the
generalized interpolation do the hard work where necessary,
simplifying the set of built-in attributes to only include the
`normal` attribute from faces.
The fact that vertex normals are just a cache also raised another
issue, because the cache could be dirty, so mutex locks were
necessary to calculate normals. That isn't necessarily a problem,
but it's nice to avoid where possible.
Another downside of the current attribute naming is that after the
point distribute node there would be two normal attributes.
This commit reverts the `vertex_normal` attribute so that
it can be replaced by the implementation in D10677.
Differential Revision: https://developer.blender.org/D10676
Currently the implementations specific to each geometry type are in
the same file. This makes it difficult to tell which code is generic
for all component types and which is specific to a certain type.
The two files, `attribute_access.cc`, and `geometry_set.cc` are
also getting quite long.
This commit splits up the implementation for every geometry component,
and adds an internal header file for the common parts of the attribute
access code. This was discussed with Jacques Lucke.
