This changes how we access the points that correspond to each curve in a `CurvesGeometry`.
Previously, `CurvesGeometry::points_for_curve(int curve_index) -> IndexRange`
was called for every curve in many loops. Now one has to call
`CurvesGeometry::points_by_curve() -> OffsetIndices` before the
loop and use the returned value inside the loop.
While this is a little bit more verbose in general, it has some benefits:
* Better standardization of how "offset indices" are used. The new data
structure can be used independent of curves.
* Allows for better data oriented design. Generally, we want to retrieve
all the arrays we need for a loop first and then do the processing.
Accessing the old `CurvesGeometry::points_for_curve(...)` did not follow
that design because it hid the underlying offset array.
* Makes it easier to pass the offsets to a function without having to
pass the entire `CurvesGeometry`.
* Can improve performance in theory due to one less memory access
because `this` does not have to be dereferenced every time.
This likely doesn't have a noticable impact in practice.
Differential Revision: https://developer.blender.org/D17025
**Changes**
As described in T93602, this patch removes all use of the `MVert`
struct, replacing it with a generic named attribute with the name
`"position"`, consistent with other geometry types.
Variable names have been changed from `verts` to `positions`, to align
with the attribute name and the more generic design (positions are not
vertices, they are just an attribute stored on the point domain).
This change is made possible by previous commits that moved all other
data out of `MVert` to runtime data or other generic attributes. What
remains is mostly a simple type change. Though, the type still shows up
859 times, so the patch is quite large.
One compromise is that now `CD_MASK_BAREMESH` now contains
`CD_PROP_FLOAT3`. With the general move towards generic attributes
over custom data types, we are removing use of these type masks anyway.
**Benefits**
The most obvious benefit is reduced memory usage and the benefits
that brings in memory-bound situations. `float3` is only 3 bytes, in
comparison to `MVert` which was 4. When there are millions of vertices
this starts to matter more.
The other benefits come from using a more generic type. Instead of
writing algorithms specifically for `MVert`, code can just use arrays
of vectors. This will allow eliminating many temporary arrays or
wrappers used to extract positions.
Many possible improvements aren't implemented in this patch, though
I did switch simplify or remove the process of creating temporary
position arrays in a few places.
The design clarity that "positions are just another attribute" brings
allows removing explicit copying of vertices in some procedural
operations-- they are just processed like most other attributes.
**Performance**
This touches so many areas that it's hard to benchmark exhaustively,
but I observed some areas as examples.
* The mesh line node with 4 million count was 1.5x (8ms to 12ms) faster.
* The Spring splash screen went from ~4.3 to ~4.5 fps.
* The subdivision surface modifier/node was slightly faster
RNA access through Python may be slightly slower, since now we need
a name lookup instead of just a custom data type lookup for each index.
**Future Improvements**
* Remove uses of "vert_coords" functions:
* `BKE_mesh_vert_coords_alloc`
* `BKE_mesh_vert_coords_get`
* `BKE_mesh_vert_coords_apply{_with_mat4}`
* Remove more hidden copying of positions
* General simplification now possible in many areas
* Convert more code to C++ to use `float3` instead of `float[3]`
* Currently `reinterpret_cast` is used for those C-API functions
Differential Revision: https://developer.blender.org/D15982
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
Use the same `".selection"` attribute for both curve and point domains,
instead of a different name for each. The attribute can now have
either boolean or float type. Some tools create boolean selections.
Other tools create float selections. Some tools "upgrade" the attribute
from boolean to float.
Edit mode tools that create selections from scratch can create boolean
selections, but edit mode should generally be able to handle both
selection types. Sculpt mode should be able to read boolean selections,
but can also and write float values between zero and one.
Theoretically we could just always use floats to store selections,
but the type-agnosticism doesn't cost too much complexity given the
existing APIs for dealing with it, and being able to use booleans is
clearer in edit mode, and may allow future optimizations like more
efficient ways to store boolean attributes.
The attribute API is usually used directly for accessing the selection
attribute. We rely on implicit type conversion and domain interpolation
to simplify the rest of the code.
Differential Revision: https://developer.blender.org/D16057
This separates the UV reverse sampling and the barycentric mixing of
the mesh attribute into separate multi-functions. This separates
concerns and allows for future de-duplication of the UV sampling
function if that is implemented as an optimization pass. That would
be helpful since it's the much more expensive operation.
This was simplified by returning the triangle index in the reverse
UV sampler rather than a pointer to the triangle, which required
passing a span of triangles separately in a few places.
When resizing mesh and curves attribute storage, avoid initializing the
new memory for basic types. Also, avoid skipping "no free" layers; all
layers should be reallocated to the new size since they may be accessed.
The semantics introduced in 25237d2625 are essential for this
change, because otherwise we don't have a way to construct non-trivial
types in the new memory.
In a basic test of the extrude node, I observed a performance
improvement of about 30%, from 55ms to 42ms.
Differential Revision: https://developer.blender.org/D15818
Use `verts` instead of `vertices` and `polys` instead of `polygons`
in the API added in 05952aa94d. This aligns better with
existing naming where the shorter names are much more common.
For copy-on-write, we want to share attribute arrays between meshes
where possible. Mutable pointers like `Mesh.mvert` make that difficult
by making ownership vague. They also make code more complex by adding
redundancy.
The simplest solution is just removing them and retrieving layers from
`CustomData` as needed. Similar changes have already been applied to
curves and point clouds (e9f82d3dc7, 410a6efb74). Removing use of
the pointers generally makes code more obvious and more reusable.
Mesh data is now accessed with a C++ API (`Mesh::edges()` or
`Mesh::edges_for_write()`), and a C API (`BKE_mesh_edges(mesh)`).
The CoW changes this commit makes possible are described in T95845
and T95842, and started in D14139 and D14140. The change also simplifies
the ongoing mesh struct-of-array refactors from T95965.
**RNA/Python Access Performance**
Theoretically, accessing mesh elements with the RNA API may become
slower, since the layer needs to be found on every random access.
However, overhead is already high enough that this doesn't make a
noticible differenc, and performance is actually improved in some
cases. Random access can be up to 10% faster, but other situations
might be a bit slower. Generally using `foreach_get/set` are the best
way to improve performance. See the differential revision for more
discussion about Python performance.
Cycles has been updated to use raw pointers and the internal Blender
mesh types, mostly because there is no sense in having this overhead
when it's already compiled with Blender. In my tests this roughly
halves the Cycles mesh creation time (0.19s to 0.10s for a 1 million
face grid).
Differential Revision: https://developer.blender.org/D15488
When the curve type attribute doesn't exist, there is no reason to
create an array for it only to fill the default value, which will add
overhead to subsequent "add" operations. I added a "get_if_single"
method to virtual array to simplify this check. Also use the existing
functions for filling curve types.
Differential Revision: https://developer.blender.org/D15560
The `DefaultMixer` for mixing generic data types has some issues:
1. The full buffer is always zeroed, even if only some is used.
2. Finalizing also works on all values, even if only some are used.
3. "mixing" doesn't allow setting the first value, requiring that
everything is cleared beforehand.
This commit adds the following functionality:
1. Constructor with the specified `IndexMask` for preliminary zeroing.
2. `set` method to overwrite the value.
3. `finalize` with the specified mask to process a subset of values.
This is useful in situations where you want to use the
DefaultMixer without having to overwrite all the values many times.
A performance improvement was observed for NURBS curve evaluation and
attribute interpolation from the point to curve domain of about 15% and
35% respectively (100,000 curves).
Differential Revision: https://developer.blender.org/D15434
UV maps that are used for surface attachment must not have overlapping
uv islands, because then the same uv coordinate would correspond to
multiple surface positions.
Ref T99936.
Previously, curves sculpt tools only worked on original data. This was
very limiting, because one could effectively only sculpt the curves when
all procedural effects were turned off. This patch adds support for curves
sculpting while looking the result of procedural effects (like deformation
based on the surface mesh). This functionality is also known as "crazy space"
support in Blender.
For more details see D15407.
Differential Revision: https://developer.blender.org/D15407
This commit removes the use of PolySpline for resampling curves and
replaces it with the length parameterization utility for that purpose.
I didn't test performance, but I would expect the shrinking to be
slightly faster because I reused some arrays to avoid allocating
them for every curve. I noted some potential improvements in
the "add curves" function.
Differential Revision: https://developer.blender.org/D15342
This splits out the code that samples points on a surface and the
code that initializes new curves. This code will be reused by D15134.
Differential Revision: https://developer.blender.org/D15216
