Previously, the lifetimes of anonymous attributes were determined by
reference counts which were non-deterministic when multiple threads
are used. Now the lifetimes of anonymous attributes are handled
more explicitly and deterministically. This is a prerequisite for any kind
of caching, because caching the output of nodes that do things
non-deterministically and have "invisible inputs" (reference counts)
doesn't really work.
For more details for how deterministic lifetimes are achieved, see D16858.
No functional changes are expected. Small performance changes are expected
as well (within few percent, anything larger regressions should be reported as
bugs).
Differential Revision: https://developer.blender.org/D16858
a5e7657cee didn't account for slices of zero sizes, and the asserts
were slightly incorrect otherwise. Also, the change didn't apply to
`Span`, only `MutableSpan`, which was a mistake. This also adds "safe"
methods to `IndexMask`, and switches function calls where necessary.
String attributes are intentionally not fully supported in geometry nodes
yet because more design work is necessary to decide how they should behave.
For now just disable handling string attributes to avoid crashes.
This is the last node to use the `CurveEval` type. Since the curve to
points node is basically the same as the resample node, now it just
reuses the resample code and moves the curve point `CustomData` to a
new point cloud at the end. I had to add support for sampling tangents
and normals to the resampling.
There is one behavior change: If the radius attribute doesn't exist,
the node won't set the radius to 1 for the output point cloud anymore.
Instead, the default radius for point clouds will be used.
That issue was similar to T99814.
Differential Revision: https://developer.blender.org/D16008
Using the same `GeometryComponentFieldContext` for all situations,
even when only one geometry type is supported is misleading, and mixes
too many different abstraction levels into code that could be simpler.
With the attribute API moved out of geometry components recently,
the "component" system is just getting in the way here.
This commit adds specific field contexts for geometry types: meshes,
curves, point clouds, and instances. There are also separate field input
helper classes, to help reduce boilerplate for fields that only support
specific geometry types.
Another benefit of this change is that it separates geometry components
from fields, which makes it easier to see the purpose of the two concepts,
and how they relate.
Because we want to be able to evaluate a field on just `CurvesGeometry`
rather than the full `Curves` data-block, the generic "geometry context"
had to be changed to avoid using `GeometryComponent`, since there is
no corresponding geometry component type. The resulting void pointer
is ugly, but only turns up in three places in practice. When Apple clang
supports `std::variant`, that could be used instead.
Differential Revision: https://developer.blender.org/D15519
These mutable pointers present problems with ownership in relation to
proper copy-on-write for attributes. The simplest solution is to just
remove them and retrieve the layers from `CustomData` when they are
needed. This also removes the complexity and redundancy of having to
update the pointers as the curves change. A similar change will apply
to meshes and point clouds.
One downside of this change is that it makes random access with RNA
slower. However, it's simple to just use the RNA attribute API instead,
which is unaffected. In this patch I updated Cycles to do that. With
the future attribute CoW changes, this generic approach makes sense
because Cycles can just request ownership of the existing arrays.
Differential Revision: https://developer.blender.org/D15486
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
This refactor had two main goals:
* Simplify the sampling code by using an algorithm with fewer special cases.
* Generalize the sampling to support non-sorted samples.
The `SampleSegmentHint` optimization was inspired by `ValueAccessor` from
OpenVDB and improves performance 2x in my test cases.
Differential Revision: https://developer.blender.org/D15348
This commit ports the "Set Spline Type" node to the new curves type.
Performance should be improved in similar ways to the other refactors
from the conversion task (T95443). Converting to and from Catmull Rom
curves is now supported. There are a few cases where a lot of work can
be skipped: when the number of points doesn't change, and when the
types already match the goal type.
The refactor has a few other explicit goals as well:
- Don't count on initialization of attribute arrays when they are
first allocated.
- Avoid copying the entire data-block when possible.
- Make decisions about which attributes to copy when changing curves
more obvious.
- Use higher-level methods to copy data between curve points.
- Optimize for the common cases of single types and full selections.
- Process selected curves of the same types in the same loop.
The Bezier to NURBS conversion is written by Piotr Makal (@pmakal).
Differential Revision: https://developer.blender.org/D14769
This commit adds an option to interpolate the number of control points
in new curves based on the count in neighboring existing curves. The
idea is to provide a more automatic default than manually controlling
the number of points in a curve, so users don't have to think about
the resolution quite as much.
Internally, some utilities for creating new curves are extracted to a
new header file. These can be used for the various nodes and operators
that create new curves.
The top-bar UI will be adjusted in a separate patch, probably moving
all of the settings that affect the size and shape of the new curves
into a popover.
Differential Revision: https://developer.blender.org/D14877
