This adds a new type of zone to Geometry Nodes that allows executing some nodes
for each element in a geometry.
## Features
* The `Selection` input allows iterating over a subset of elements on the set
domain.
* Fields passed into the input node are available as single values inside of the
zone.
* The input geometry can be split up into separate (completely independent)
geometries for each element (on all domains except face corner).
* New attributes can be created on the input geometry by outputting a single
value from each iteration.
* New geometries can be generated in each iteration.
* All of these geometries are joined to form the final output.
* Attributes from the input geometry are propagated to the output
geometries.
## Evaluation
The evaluation strategy is similar to the one used for repeat zones. Namely, it
dynamically builds a `lazy_function::Graph` once it knows how many iterations
are necessary. It contains a separate node for each iteration. The inputs for
each iteration are hardcoded into the graph. The outputs of each iteration a
passed to a separate lazy-function that reduces all the values down to the final
outputs. This final output can have a huge number of inputs and that is not
ideal for multi-threading yet, but that can still be improved in the future.
## Performance
There is a non-neglilible amount of overhead for each iteration. The overhead is
way larger than the per-element overhead when just doing field evaluation.
Therefore, normal field evaluation should be preferred when possible. That can
partially still be optimized if there is only some number crunching going on in
the zone but that optimization is not implemented yet.
However, processing many small geometries (e.g. each hair of a character
separately) will likely **always be slower** than working on fewer larger
geoemtries. The additional flexibility you get by processing each element
separately comes at the cost that Blender can't optimize the operation as well.
For node groups that need to handle lots of geometry elements, we recommend
trying to design the node setup so that iteration over tiny sub-geometries is
not required.
An opposite point is true as well though. It can be faster to process more
medium sized geometries in parallel than fewer very large geometries because of
more multi-threading opportunities. The exact threshold between tiny, medium and
large geometries depends on a lot of factors though.
Overall, this initial version of the new zone does not implement all
optimization opportunities yet, but the points mentioned above will still hold
true later.
Pull Request: https://projects.blender.org/blender/blender/pulls/127331
Along with the 4.1 libraries upgrade, we are bumping the clang-format
version from 8-12 to 17. This affects quite a few files.
If not already the case, you may consider pointing your IDE to the
clang-format binary bundled with the Blender precompiled libraries.
This struct is currently defined in the `functions` module but not actually used there. It's only used by the geometry nodes module, with an indirect dependency from blenkernel via simulation zone baking. This scope is problematic when adding grids as socket data, which should not be part of the functions module.
The `ValueOrField` struct is now moved to blenkernel, so it can be more easily extended to other kinds of data that might be passed around by geometry nodes sockets in future. No functional changes.
Pull Request: https://projects.blender.org/blender/blender/pulls/115087
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.
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/
Goals of this refactor:
* Reduce memory consumption of `IndexMask`. The old `IndexMask` uses an
`int64_t` for each index which is more than necessary in pretty much all
practical cases currently. Using `int32_t` might still become limiting
in the future in case we use this to index e.g. byte buffers larger than
a few gigabytes. We also don't want to template `IndexMask`, because
that would cause a split in the "ecosystem", or everything would have to
be implemented twice or templated.
* Allow for more multi-threading. The old `IndexMask` contains a single
array. This is generally good but has the problem that it is hard to fill
from multiple-threads when the final size is not known from the beginning.
This is commonly the case when e.g. converting an array of bool to an
index mask. Currently, this kind of code only runs on a single thread.
* Allow for efficient set operations like join, intersect and difference.
It should be possible to multi-thread those operations.
* It should be possible to iterate over an `IndexMask` very efficiently.
The most important part of that is to avoid all memory access when iterating
over continuous ranges. For some core nodes (e.g. math nodes), we generate
optimized code for the cases of irregular index masks and simple index ranges.
To achieve these goals, a few compromises had to made:
* Slicing of the mask (at specific indices) and random element access is
`O(log #indices)` now, but with a low constant factor. It should be possible
to split a mask into n approximately equally sized parts in `O(n)` though,
making the time per split `O(1)`.
* Using range-based for loops does not work well when iterating over a nested
data structure like the new `IndexMask`. Therefor, `foreach_*` functions with
callbacks have to be used. To avoid extra code complexity at the call site,
the `foreach_*` methods support multi-threading out of the box.
The new data structure splits an `IndexMask` into an arbitrary number of ordered
`IndexMaskSegment`. Each segment can contain at most `2^14 = 16384` indices. The
indices within a segment are stored as `int16_t`. Each segment has an additional
`int64_t` offset which allows storing arbitrary `int64_t` indices. This approach
has the main benefits that segments can be processed/constructed individually on
multiple threads without a serial bottleneck. Also it reduces the memory
requirements significantly.
For more details see comments in `BLI_index_mask.hh`.
I did a few tests to verify that the data structure generally improves
performance and does not cause regressions:
* Our field evaluation benchmarks take about as much as before. This is to be
expected because we already made sure that e.g. add node evaluation is
vectorized. The important thing here is to check that changes to the way we
iterate over the indices still allows for auto-vectorization.
* Memory usage by a mask is about 1/4 of what it was before in the average case.
That's mainly caused by the switch from `int64_t` to `int16_t` for indices.
In the worst case, the memory requirements can be larger when there are many
indices that are very far away. However, when they are far away from each other,
that indicates that there aren't many indices in total. In common cases, memory
usage can be way lower than 1/4 of before, because sub-ranges use static memory.
* For some more specific numbers I benchmarked `IndexMask::from_bools` in
`index_mask_from_selection` on 10.000.000 elements at various probabilities for
`true` at every index:
```
Probability Old New
0 4.6 ms 0.8 ms
0.001 5.1 ms 1.3 ms
0.2 8.4 ms 1.8 ms
0.5 15.3 ms 3.0 ms
0.8 20.1 ms 3.0 ms
0.999 25.1 ms 1.7 ms
1 13.5 ms 1.1 ms
```
Pull Request: https://projects.blender.org/blender/blender/pulls/104629
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 moves all multi-function related code in the `functions` module
into a new `multi_function` namespace. This is similar to how there
is a `lazy_function` namespace.
The main benefit of this is that many types names that were prefixed
with `MF` (for "multi function") can be simplified.
There is also a common shorthand for the `multi_function` namespace: `mf`.
This is also similar to lazy-functions where the shortened namespace
is called `lf`.
This is part of D16858. Iterating over all field inputs allows us to extract
all anonymous attributes used by a field relatively easily which is necessary
for D16858.
This could potentially be used for better field tooltips for nested fields,
but that needs further investigation.
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*/`
This refactors the geometry nodes evaluation system. No changes for the
user are expected. At a high level the goals are:
* Support using geometry nodes outside of the geometry nodes modifier.
* Support using the evaluator infrastructure for other purposes like field evaluation.
* Support more nodes, especially when many of them are disabled behind switch nodes.
* Support doing preprocessing on node groups.
For more details see T98492.
There are fairly detailed comments in the code, but here is a high level overview
for how it works now:
* There is a new "lazy-function" system. It is similar in spirit to the multi-function
system but with different goals. Instead of optimizing throughput for highly
parallelizable work, this system is designed to compute only the data that is actually
necessary. What data is necessary can be determined dynamically during evaluation.
Many lazy-functions can be composed in a graph to form a new lazy-function, which can
again be used in a graph etc.
* Each geometry node group is converted into a lazy-function graph prior to evaluation.
To evaluate geometry nodes, one then just has to evaluate that graph. Node groups are
no longer inlined into their parents.
Next steps for the evaluation system is to reduce the use of threads in some situations
to avoid overhead. Many small node groups don't benefit from multi-threading at all.
This is much easier to do now because not everything has to be inlined in one huge
node tree anymore.
Differential Revision: https://developer.blender.org/D15914
Use the newer more generic sampling and interpolation functions
developed recently (ab444a80a2) instead of the `CurveEval` type.
Functions are split up a bit more internally, to allow a separate mode
for supplying the curve index directly in the future (T92474).
In one basic test, the performance seems mostly unchanged from 3.1.
Differential Revision: https://developer.blender.org/D14621
The separate geometry and delete geometry nodes often invert the
selection so that deleting elements from a geometry can be implemented
as copying the opposite selection of elements. This should make the two
nodes faster in some cases, since the generic versions of selection
creation functions (i.e. from d3a1e9cbb9) are used instead
of the single threaded code that was used for this node.
The change also makes the deletion/separation code easier to
understand because it doesn't have to pass around the inversion.
Since {rBeae36be372a6b16ee3e76eff0485a47da4f3c230} the distinction
between float and byte colors is more explicit in the ui. So far, geometry
nodes couldn't really deal with byte colors in general. This patch fixes that.
There is still only one color socket, which contains float colors. Conversion
to and from byte colors is done when read from or writing to attributes.
* Support writing to byte color attributes in Store Named Attribute node.
* Support converting to/from byte color in attribute conversion operator.
* Support propagating byte color attributes.
* Add all the implicit conversions from byte colors to the other types.
* Display byte colors as integers in spreadsheet.
Differential Revision: https://developer.blender.org/D14705
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
Every translation unit that included the modified headers generated
some extra code, even though it was not used. This adds unnecessary
compile time overhead and is annoying when investigating the
generated assembly.
It is common to have fields that contain a constant value. Before this
commit, such constants were represented by operation nodes which
don't have inputs. Having a special node type for constants makes
working with them a bit cheaper.
It also allows skipping some unnecessary processing when evaluating
fields, because constant fields can be detected more easily.
This commit also generalizes the concept of field node types a bit.
We often had to use two `FieldEvaluator` instances to first evaluate
the selection and then the remaining fields. Now both can be done
with a single `FieldEvaluator`. This results in less boilerplate code in
many cases.
Performance is not affected by this change. In a separate patch we
could improve performance by reusing evaluated sub-fields that are
used by the selection and the other fields.
Differential Revision: https://developer.blender.org/D13571
This implements an optimization pass for multi-function procedures.
It optimizes memory reuse by moving destruct instructions up.
For more details see the in-code comment.
In very large fields with many short lived intermediate values, this change
can improve performance 3-4x. Furthermore, in such cases, peak memory
consumption is reduced significantly (e.g. 100x lower peak memory usage).
Differential Revision: https://developer.blender.org/D13548
Calling `foreach_field_input` on a highly nested field (we do that
often) has an exponential running time in the number of nodes.
That is because the same node may be visited many times.
This made Blender freeze on some setups that should work just fine.
Now every field keeps track of its inputs all the time. That replaces
the exponential algorithm with constant time access.
Most of our field inputs are currently specific to geometry. This patch introduces
a new `GeometryFieldInput` that reduces the overhead of adding new geometry
field input.
Differential Revision: https://developer.blender.org/D13489
Currently the geometry nodes evaluator always stores a field for every
type that supports it, even if it is just a single value. This results in a lot
of overhead when there are many sockets that just contain a single
value, which is often the case.
This introduces a new `ValueOrField<T>` type that is used by the geometry
nodes evaluator. Now a field will only be created when it is actually
necessary. See D13307 for more details. In extrem cases this can speed
up the evaluation 2-3x (those cases are probably never hit in practice
though, but it's good to get rid of unnecessary overhead nevertheless).
Differential Revision: https://developer.blender.org/D13307
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
We do this in other nodes to reduce overhead of using the same node more
than once. I don't think it will make a difference with index nodes
currently, but at least it's consistent.
Previously, some multi-functions were allocated in a resource scope.
This was fine as long as the multi-functions were only needed during
the current evaluation of the node tree. However, now cases arise
that require the multi-functions to be alive after the modifier is finished.
For example, we want to evaluate fields created with geometry nodes
outside of geometry nodes.
To make this work, `std::shared_ptr` has to be used in a few more places.
Realistically, this shouldn't have a noticable impact on performance.
If this does become a bottleneck in the future, we can think about ways
to make this work without using `shared_ptr` for multi-functions that
are only used once.
Previously, a debug name had to be passed to all methods
that added a resource to the `ResourceScope`. The idea was
that this would make it easier to find certain bugs. In reality
I never found this to be useful, and it was mostly annoying.
The thing is, something that is in a resource scope never leaks
(unless the resource scope is not destructed of course).
Removing the name parameter makes the structure easier to use.
Instead of comparing the referenced field node by pointer,
compare the nodes directly instead. This is important
because different field nodes might be the same semantically.
Since fields were committed to master, socket inspection did
not work correctly for all socket types anymore. Now the same
functionality as before is back. Furthermore, fields that depend
on some input will now show the inputs in the socket inspection.
I added support for evaluating constant fields more immediately.
This has the benefit that the same constant field is not evaluated
more than once. It also helps with making the field independent
of the multi-functions that it uses. We might still want to change
the ownership handling for the multi-functions of nodes a bit,
but that can be done separately.
Differential Revision: https://developer.blender.org/D12444
This implements the initial core framework for fields and anonymous
attributes (also see T91274).
The new functionality is hidden behind the "Geometry Nodes Fields"
feature flag. When enabled in the user preferences, the following
new nodes become available: `Position`, `Index`, `Normal`,
`Set Position` and `Attribute Capture`.
Socket inspection has not been updated to work with fields yet.
Besides these changes at the user level, this patch contains the
ground work for:
* building and evaluating fields at run-time (`FN_fields.hh`) and
* creating and accessing anonymous attributes on geometry
(`BKE_anonymous_attribute.h`).
For evaluating fields we use a new so called multi-function procedure
(`FN_multi_function_procedure.hh`). It allows composing multi-functions
in arbitrary ways and supports efficient evaluation as is required by
fields. See `FN_multi_function_procedure.hh` for more details on how
this evaluation mechanism can be used.
A new `AttributeIDRef` has been added which allows handling named
and anonymous attributes in the same way in many places.
Hans and I worked on this patch together.
Differential Revision: https://developer.blender.org/D12414
