Commit Graph

66 Commits

Author SHA1 Message Date
Hans Goudey
19e2b13cec Cleanup: Move BKE_key.h to C++ 2024-01-30 14:42:13 -05:00
Brecht Van Lommel
d377ef2543 Clang Format: bump to version 17
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.
2024-01-03 13:38:14 +01:00
Hans Goudey
b9b47088bc Cleanup: Remove unnecessary DNA_meshdata_types.h includes
Except for vertex groups and a few older color types, these
are generally replaced by newer generic attribute types.
Also remove some includes of DNA_mesh_types.h, since it's
included indirectly by BKE_mesh.hh currently.
2023-12-20 20:58:38 -05:00
Hans Goudey
8dd8f932e2 Cleanup: Rename Mesh loop_data to corner_data
Related to #110434, efbee2d606, 7c69c8827b
2023-12-19 20:39:05 -05:00
Hans Goudey
efbee2d606 Mesh: Rename totvert, totedge, and totloop fields
Use the standard "elements_num" naming, and use the "corner" name rather
than the old "loop" name: `verts_num`, `edges_num`, and `corners_num`.
This matches the existing `faces_num` field which was already renamed.

Pull Request: https://projects.blender.org/blender/blender/pulls/116350
2023-12-20 02:21:48 +01:00
Hans Goudey
eb399678f5 Fix #115366: Missing task isolation subdividing loose edges
Nowadays we have the loose edge cache which can tell us if there will be
any loose edges to subdivide. This means the topology map creation that
included multi-threading doesn't need to be behind a lock anymore.

Pull Request: https://projects.blender.org/blender/blender/pulls/115480
2023-11-27 15:19:44 +01:00
Hans Goudey
3d57bc4397 Cleanup: Move several blenkernel headers to C++
Mostly focus on areas where we're already using C++ features,
where combining C and C++ APIs is getting in the way.

Pull Request: https://projects.blender.org/blender/blender/pulls/114972
2023-11-16 11:41:55 +01:00
Hans Goudey
9785f2631e Mesh: Add flag to store presence of overlapping topology
For improving performance in the triangulate node (#112264), it's
helpful to know whether the mesh has edges or faces that overlap
each other. If that is known to be false, the node can skip edge de-
duplication.This might apply to the future "Replace Faces" node too.

This information is stored as a flag on the mesh and set in various
places that create "clean" new meshes. It isn't calculated lazily unlike
other other areas, because the point is to improve performance, and
the calculation probably isn't faster than the duplication check it's
meant to replace.

Pull Request: https://projects.blender.org/blender/blender/pulls/113205
2023-11-15 14:02:48 +01:00
Hans Goudey
bb181fb8f1 Cleanup: Remove redundant asserts about dirty normals
These asserts basically just reiterated the way things work-- there's no
no way for them to trigger with the current code. And even if they did,
that sort of change wouldn't happen by mistake, so it's not worth
an assert.
2023-08-31 14:22:22 -04:00
Campbell Barton
e955c94ed3 License Headers: Set copyright to "Blender Authors", add AUTHORS
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.
2023-08-16 00:20:26 +10:00
Hans Goudey
731d296f35 Cleanup: Move mesh related blenkernel headers to C++
See #103343

Pull Request: https://projects.blender.org/blender/blender/pulls/110730
2023-08-02 22:14:18 +02:00
Hans Goudey
aebc743bf1 Cleanup: Make format
Sorry for the noise, I thought I ran this in the previous commit.
2023-07-25 15:23:56 -04:00
Hans Goudey
95edff7495 Cleanup: Rename mesh custom data fields
Implements the rest of #101689, after 5e9ea9243b.

- `vdata` -> `vert_data`
- `edata` -> `edge_data`
- `pdata` -> `face_data`
- `ldata` -> `loop_data`

A deeper rename of `loop` to `corner` will be proposed as a next
step, and renaming `totvert` and `totedge` can be done separately.

Pull Request: https://projects.blender.org/blender/blender/pulls/110432
2023-07-25 21:15:52 +02:00
Hans Goudey
f3f31054ba Cleanup: Make format 2023-07-24 16:32:08 -04:00
Hans Goudey
5e9ea9243b Mesh: Rename "polys" to "faces"
Implements part of #101689.

The "poly" name was chosen to distinguish the `MLoop` + `MPoly`
combination from the `MFace` struct it replaced. Those two structures
persisted together for a long time, but nowadays `MPoly` is gone, and
`MFace` is only used in some legacy code like the particle system.

To avoid unnecessarily using a different term, increase consistency
with the UI and with BMesh, and generally make code a bit easier to
read, this commit replaces the `poly` term with `poly`. Most variables
that use the term are renamed too. `Mesh.totface` and `Mesh.fdata` now
have a `_legacy` suffix to reduce confusion. In a next step, `pdata`
can be renamed to `face_data` as well.

Pull Request: https://projects.blender.org/blender/blender/pulls/109819
2023-07-24 22:06:55 +02:00
Campbell Barton
785bd13b9a Cleanup: spelling in comments 2023-07-05 14:09:33 +10:00
Hans Goudey
68c6402666 Cleanup: Use C++ accessor for mesh position attribute 2023-06-14 12:37:52 -04:00
Hans Goudey
e5ec04d73c Mesh: Move vertex/edge crease to generic attributes
Store subdivision surface creases in two new named float attributes:
- `crease_vert`
- `crease_edge`
This is similar to 2a56403cb0.

The attributes are naming conventions, so their data type and domain
aren't enforced, and may be interpolated when necessary. Editing tools
and the subdivision surface modifier use the hard-coded name. It might
be best if these were edited as generic attributes in the future, but
in the meantime using generic attributes helps.

The attributes are visible in the list, which is how they're now meant
to be removed. They are now interchangeable with any tool that works
with the generic attribute system-- even tools like vertex paint can
affect creases now.

This is a breaking change. Forward compatibility isn't preserved for
versions before 3.6, and the `crease` property in RNA is removed in
favor of making a smaller API surface area with just the attribute API.
`Mesh.vertex_creases` and `Mesh.edge_creases` now just return the
matching attribute if possible, and are now implemented in Python.
New functions `*ensure` and `*remove` also replace the operators to
add and remove the layers for Python.

A few extrude node test files have to be updated because of different
(now generic) attribute interpolation behavior.

Pull Request: https://projects.blender.org/blender/blender/pulls/108089
2023-06-13 20:23:39 +02:00
Sergey Sharybin
c1bc70b711 Cleanup: Add a copyright notice to files and use SPDX format
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/
2023-05-31 16:19:06 +02:00
Hans Goudey
4d841e1b35 Mesh: Reimplement and unify topology maps
Combine the newer less efficient C++ implementations and the older
less convenient C functions. The maps now contain one large array of
indices, split into groups by a separate array of offset indices.
Though performance of creating the maps is relatively unchanged, the
new implementation uses 4 bytes less per source element than the C
maps, and 20 bytes less than the newer C++ functions (which also
had more overhead with larger N-gons). The usage syntax is simpler
than the C functions as well.

The reduced memory usage is helpful for when these maps are cached
in the near future. It will also allow sharing the offsets between
maps for different domains like vertex to corner and vertex to face.

A simple `GroupedSpan` class is introduced to make accessing the
topology maps much simpler. It combines offset indices and a separate
span, splitting it into chunks in an efficient way.

Pull Request: https://projects.blender.org/blender/blender/pulls/107861
2023-05-24 13:16:57 +02:00
Hans Goudey
71d22331b1 Cleanup: Rename mesh loose edges tag function
To match the more recently added `tag_loose_verts_none`.
2023-05-18 23:06:15 -04:00
Campbell Barton
6859bb6e67 Cleanup: format (with BraceWrapping::AfterControlStatement "MultiLine") 2023-05-02 09:37:49 +10:00
Hans Goudey
54072154c5 Subdiv: Tag result mesh with no loose edges/verts
Avoid possible calculations of loose edges later on if the coarse mesh
doesn't have loose edges or vertices. We expect these counts to be
cached already since `BKE_subdiv_converter_init_for_mesh` calls
`verts_no_face()` and `loose_edges()` already.

Related commits:
- 63689e4756
- 8e967cfeaf
2023-04-23 15:27:20 -04:00
Hans Goudey
5bed959e81 Cleanup: Avoid magic number for bits per integer 2023-04-23 15:27:20 -04:00
Hans Goudey
10d175e223 Cleanup: Use consistent argument order for mesh creation functions
The typical order is vertex, edge, face(polygon), corner(loop), but in
these three functions polys and loops were reversed. Also use more
typical "num" variable names rather than "len"
2023-04-19 15:52:56 -04:00
Hans Goudey
2a4323c2f5 Mesh: Move edges to a generic attribute
Implements #95966, as the final step of #95965.

This commit changes the storage of mesh edge vertex indices from the
`MEdge` type to the generic `int2` attribute type. This follows the
general design for geometry and the attribute system, where the data
storage type and the usage semantics are separated.

The main benefit of the change is reduced memory usage-- the
requirements of storing mesh edges is reduced by 1/3. For example,
this saves 8MB on a 1 million vertex grid. This also gives performance
benefits to any memory-bound mesh processing algorithm that uses edges.

Another benefit is that all of the edge's vertex indices are
contiguous. In a few cases, it's helpful to process all of them as
`Span<int>` rather than `Span<int2>`. Similarly, the type is more
likely to match a generic format used by a library, or code that
shouldn't know about specific Blender `Mesh` types.

Various Notes:
- The `.edge_verts` name is used to reflect a mapping between domains,
  similar to `.corner_verts`, etc. The period means that it the data
  shouldn't change arbitrarily by the user or procedural operations.
- `edge[0]` is now used instead of `edge.v1`
- Signed integers are used instead of unsigned to reduce the mixing
  of signed-ness, which can be error prone.
- All of the previously used core mesh data types (`MVert`, `MEdge`,
  `MLoop`, `MPoly` are now deprecated. Only generic types are used).
- The `vec2i` DNA type is used in the few C files where necessary.

Pull Request: https://projects.blender.org/blender/blender/pulls/106638
2023-04-17 13:47:41 +02:00
Jacques Lucke
7eee378ecc Custom Data: support implicit sharing for custom data layers
This integrates the new implicit-sharing system (from fbcddfcd68)
with `CustomData`. Now the potentially long arrays referenced by custom
data layers can be shared between different systems but most importantly
between different geometries. This makes e.g. copying a mesh much cheaper
because none of the attributes has to be copied. Only when an attribute
is modified does it have to be copied.

Also see the original design task: #95845.

This reduces memory and improves performance by avoiding unnecessary
data copies. For example, the used memory after loading a highly
subdivided mesh is reduced from 2.4GB to 1.79GB. This is about 25%
less which is the expected amount because in `main` there are 4 copies
of the data:
1. The original data which is allocated when the file is loaded.
2. The copy for the depsgraph allocated during depsgraph evaluation.
3. The copy for the undo system allocated when the first undo step is
  created right after loading the file.
4. GPU buffers allocated for drawing.

This patch only gets rid of copy number 2 for the depsgraph. In theory
the other copies can be removed as part of follow up PRs as well though.

-----

The patch has three main components:
* Slightly modified `CustomData` API to make it work better with implicit
  sharing:
  * `CD_REFERENCE` and `CD_DUPLICATE` have been removed because they are
    meaningless when implicit-sharing is used.
  * `CD_ASSIGN` has been removed as well because it's not an allocation
    type anyway. The functionality of using existing arrays as custom
    data layers has not been removed though.
  * This can still be done with `CustomData_add_layer_with_data` which
    also has a new argument that allows passing in information about
    whether the array is shared.
  * `CD_FLAG_NOFREE` has been removed because it's no longer necessary. It
    only existed because of `CD_REFERENCE`.
  * `CustomData_copy` and `CustomData_merge` have been split up into a
    functions that do copy the actual attribute values and those that do
    not. The latter functions now have the `_layout` suffix
    (e.g. `CustomData_copy_layout`).
* Changes in `customdata.cc` to make it actually use implicit-sharing.
* Changes in various other files to adapt to the changes in `BKE_customdata.h`.

Pull Request: https://projects.blender.org/blender/blender/pulls/106228
2023-04-13 14:57:57 +02:00
Hans Goudey
fd234fe1ce Fix #106745: Subdivision surface crash with more than 8 UV maps
Before 6c774feba2, the maximum number of UV maps was
enforced throughout Blender. Now it has to be enforced in the few places
that actually have the limit. In the future the limit of the subsurf
could be lifted, but that isn't done now to keep the crash fix simple.
2023-04-11 15:28:08 -04:00
Hans Goudey
7966cd16d6 Mesh: Replace MPoly struct with offset indices
Implements #95967.

Currently the `MPoly` struct is 12 bytes, and stores the index of a
face's first corner and the number of corners/verts/edges. Polygons
and corners are always created in order by Blender, meaning each
face's corners will be after the previous face's corners. We can take
advantage of this fact and eliminate the redundancy in mesh face
storage by only storing a single integer corner offset for each face.
The size of the face is then encoded by the offset of the next face.
The size of a single integer is 4 bytes, so this reduces memory
usage by 3 times.

The same method is used for `CurvesGeometry`, so Blender already has
an abstraction to simplify using these offsets called `OffsetIndices`.
This class is used to easily retrieve a range of corner indices for
each face. This also gives the opportunity for sharing some logic with
curves.

Another benefit of the change is that the offsets and sizes stored in
`MPoly` can no longer disagree with each other. Storing faces in the
order of their corners can simplify some code too.

Face/polygon variables now use the `IndexRange` type, which comes with
quite a few utilities that can simplify code.

Some:
- The offset integer array has to be one longer than the face count to
  avoid a branch for every face, which means the data is no longer part
  of the mesh's `CustomData`.
- We lose the ability to "reference" an original mesh's offset array
  until more reusable CoW from #104478 is committed. That will be added
  in a separate commit.
- Since they aren't part of `CustomData`, poly offsets often have to be
  copied manually.
- To simplify using `OffsetIndices` in many places, some functions and
  structs in headers were moved to only compile in C++.
- All meshes created by Blender use the same order for faces and face
  corners, but just in case, meshes with mismatched order are fixed by
  versioning code.
- `MeshPolygon.totloop` is no longer editable in RNA. This API break is
  necessary here unfortunately. It should be worth it in 3.6, since
  that's the best way to allow loading meshes from 4.0, which is
  important for an LTS version.

Pull Request: https://projects.blender.org/blender/blender/pulls/105938
2023-04-04 20:39:28 +02:00
Sergey Sharybin
a12a8a71bb Remove "All Rights Reserved" from Blender Foundation copyright code
The goal is to solve confusion of the "All rights reserved" for licensing
code under an open-source license.

The phrase "All rights reserved" comes from a historical convention that
required this phrase for the copyright protection to apply. This convention
is no longer relevant.

However, even though the phrase has no meaning in establishing the copyright
it has not lost meaning in terms of licensing.

This change makes it so code under the Blender Foundation copyright does
not use "all rights reserved". This is also how the GPL license itself
states how to apply it to the source code:

    <one line to give the program's name and a brief idea of what it does.>
    Copyright (C) <year>  <name of author>

    This program is free software ...

This change does not change copyright notice in cases when the copyright
is dual (BF and an author), or just an author of the code. It also does
mot change copyright which is inherited from NaN Holding BV as it needs
some further investigation about what is the proper way to handle it.
2023-03-30 10:51:59 +02:00
Hans Goudey
16fbadde36 Mesh: Replace MLoop struct with generic attributes
Implements #102359.

Split the `MLoop` struct into two separate integer arrays called
`corner_verts` and `corner_edges`, referring to the vertex each corner
is attached to and the next edge around the face at each corner. These
arrays can be sliced to give access to the edges or vertices in a face.
Then they are often referred to as "poly_verts" or "poly_edges".

The main benefits are halving the necessary memory bandwidth when only
one array is used and simplifications from using regular integer indices
instead of a special-purpose struct.

The commit also starts a renaming from "loop" to "corner" in mesh code.

Like the other mesh struct of array refactors, forward compatibility is
kept by writing files with the older format. This will be done until 4.0
to ease the transition process.

Looking at a small portion of the patch should give a good impression
for the rest of the changes. I tried to make the changes as small as
possible so it's easy to tell the correctness from the diff. Though I
found Blender developers have been very inventive over the last decade
when finding different ways to loop over the corners in a face.

For performance, nearly every piece of code that deals with `Mesh` is
slightly impacted. Any algorithm that is memory bottle-necked should
see an improvement. For example, here is a comparison of interpolating
a vertex float attribute to face corners (Ryzen 3700x):

**Before** (Average: 3.7 ms, Min: 3.4 ms)
```
threading::parallel_for(loops.index_range(), 4096, [&](IndexRange range) {
  for (const int64_t i : range) {
    dst[i] = src[loops[i].v];
  }
});
```

**After** (Average: 2.9 ms, Min: 2.6 ms)
```
array_utils::gather(src, corner_verts, dst);
```

That's an improvement of 28% to the average timings, and it's also a
simplification, since an index-based routine can be used instead.
For more examples using the new arrays, see the design task.

Pull Request: https://projects.blender.org/blender/blender/pulls/104424
2023-03-20 15:55:13 +01:00
Hans Goudey
1dc57a89e9 Mesh: Move functions to C++ header
Refactoring mesh code, it has become clear that local cleanups and
simplifications are limited by the need to keep a C public API for
mesh functions. This change makes code more obvious and makes further
refactoring much easier.

- Add a new `BKE_mesh.hh` header for a C++ only mesh API
- Introduce a new `blender::bke::mesh` namespace, documented here:
  https://wiki.blender.org/wiki/Source/Objects/Mesh#Namespaces
- Move some functions to the new namespace, cleaning up their arguments
- Move code to `Array` and `float3` where necessary to use the new API
- Define existing inline mesh data access functions to the new header
- Keep some C API functions where necessary because of RNA
- Move all C++ files to use the new header, which includes the old one

In the future it may make sense to split up `BKE_mesh.hh` more, but for
now keeping the same name as the existing header keeps things simple.

Pull Request: https://projects.blender.org/blender/blender/pulls/105416
2023-03-12 22:29:15 +01:00
Hans Goudey
915ff8d152 Cleanup: Use references for mesh poly variables
Similar to the previous commit, this simplifies future refactoring
to change the way edges are stored, and further differentiates
single poly variables from array pointers.
2023-03-03 11:40:43 -05:00
Hans Goudey
b37111c574 Cleanup: Use consistent "vert" term for mesh normals
Use "vert" instead of "vertex" when referring to mesh normals. This was
discussed as part of 1af62cb3bf but never completely
implemented.
2023-02-27 15:52:29 -05:00
Hans Goudey
baa27d0aef Fix: Explode modifier cycles test failure after recent cleanup
Caused by 96abaae9ac. Just keep the old argument
in the `_ex` version of the function for now. It can be removed
when the explode modifier is removed in 4.0.
2023-02-27 15:29:52 -05:00
Hans Goudey
52104c1a0c Mesh: Avoid recalculating bounds after some operations
Share the bounds cache across the input and output meshes of some
mesh operations that don't change the min and max positions: simple
subdivision, edge/face deletion, and triangulation. If the source mesh's
bounds are computed, or if the mesh is persistent, this can save
recalculation of the bounding box, which takes a few milliseconds
for large meshes.
2023-02-27 12:31:09 -05:00
Hans Goudey
96abaae9ac Cleanup: Remove legacy argument from mesh creation functions
The legacy `tessface_len` argument was only used for the explode
modifier. Remove it and copy the legacy face data manually there.
2023-02-27 11:24:22 -05:00
Hans Goudey
ca2c0da79e Merge branch 'blender-v3.5-release' 2023-02-26 18:09:18 -05:00
Hans Goudey
3db246a3ce Fix #104915: Race condition writing subsurf optimal display edges
Writing to a bitmap from multiple threads causes races when writing to
bits within the same integer. Instead, write to a separate boolean
array while subdividing, then move that to the final mesh bit vector.

Notes:
 - The final copy to the bit vector could be replaced by a generic
   `copy_from(Span<bool>)` call in the future.
 - Theoretically we could entirely replace the `BitVector` with an
   `Array<bool>`, but 1/8 the memory use for edges is likely worth it.

Pull Request #105156
2023-02-26 23:59:02 +01:00
Hans Goudey
2491cd5e16 Cleanup: Move two subdiv headers to C++ 2023-02-23 18:30:47 -05:00
Hans Goudey
cb62ab5b28 Cleanup: Access mesh edges, faces, and loops with spans
Using spans instead of raw pointers helps to differentiate ararys from
pointers to single elements, gives bounds checking in debug builds, and
conveniently stores the number of elements in the same variable.

Also make variable naming consistent. For example, use `loops` instead
of `mloop`. The plural helps to clarify that the variable is an array.

I didn't change positions because there is a type mismatch between
C and C++ code that is ugly to manage. All remaining code can be
converted to C++, then that change will be simpler.

Pull Request #105138
2023-02-23 17:14:03 +01:00
Hans Goudey
7ca651d182 Mesh: Remove unnecessary edge draw flag
As described in #95966, replace the `ME_EDGEDRAW` flag with a bit
vector in mesh runtime data. Currently the the flag is only ever set
to false for the "optimal display" feature of the subdivision surface
modifier. When creating an "original" mesh in the main data-base,
the flag is always supposed to be true.

The bit vector is now created by the modifier only as necessary, and
is cleared for topology-changing operations. This fixes incorrect
interpolation of the flag as noted in #104376. Generally it isn't
possible to interpolate it through topology-changing operations.

After this, only the seam status needs to be removed from edges before
we can replace them with the generic `int2` type (or something similar)
and reduce memory usage by 1/3.

Related:
- 10131a6f62
- 145839aa42

In the future `BM_ELEM_DRAW` could be removed as well. Currently it is
used and aliased by other defines in some non-obvious ways though.

Pull Request #104417
2023-02-09 15:56:05 +01:00
Hans Goudey
75db4c082b Cleanup: Use BitVector instead of BLI_bitmap for subsurf face dot tags
For better type safety and more automatic memory management.
2023-02-06 14:13:53 -05:00
Hans Goudey
c7b601c79e Cleanup: Subdiv: Use index instead of pointer
The edge pointer was retrieved from the index and then just
used to calculate the index again. Remove the edge pointer
and only use the index.
2023-02-06 12:29:01 -05:00
Brecht Van Lommel
12a3de96bb Fix T103972: crash with cloth simulation rest shape key and subdivision surface 2023-01-19 17:33:12 +01:00
Hans Goudey
3a3d9488a1 Refactor: Const correct Custom Data API, prepare for CoW
Currently you can retrieve a mutable array from a const CustomData.
That makes code unsafe since the compiler can't check for correctness
itself. Fix that by introducing a separate function to retrieve mutable
arrays from CustomData. The new functions have the `_for_write`
suffix that make the code's intention clearer.

Because it makes retrieving write access an explicit step, this change
also makes proper copy-on-write possible for attributes.

Notes:
- The previous "duplicate referenced layer" functions are redundant
  with retrieving layers with write access
- The custom data functions that give a specific index only have
  `for_write` to simplify the API

Differential Revision: https://developer.blender.org/D14140
2023-01-13 17:22:07 -06:00
Martijn Versteegh
6c774feba2 Mesh: Move UV layers to generic attributes
Currently the `MLoopUV` struct stores UV coordinates and flags related
to editing UV maps in the UV editor. This patch changes the coordinates
to use the generic 2D vector type, and moves the flags into three
separate boolean attributes. This follows the design in T95965, with
the ultimate intention of simplifying code and improving performance.

Importantly, the change allows exporters and renderers to use UVs
"touched" by geometry nodes, which only creates generic attributes.
It also allows geometry nodes to create "proper" UV maps from scratch,
though only with the Store Named Attribute node for now.

The new design considers any 2D vector attribute on the corner domain
to be a UV map. In the future, they might be distinguished from regular
2D vectors with attribute metadata, which may be helpful because they
are often interpolated differently.

Most of the code changes deal with passing around UV BMesh custom data
offsets and tracking the boolean "sublayers". The boolean layers are
use the following prefixes for attribute names: vert selection: `.vs.`,
edge selection: `.es.`, pinning: `.pn.`. Currently these are short to
avoid using up the maximum length of attribute names. To accommodate
for these 4 extra characters, the name length limit is enlarged to 68
bytes, while the maximum user settable name length is still 64 bytes.

Unfortunately Python/RNA API access to the UV flag data becomes slower.
Accessing the boolean layers directly is be better for performance in
general.

Like the other mesh SoA refactors, backward and forward compatibility
aren't affected, and won't be changed until 4.0. We pay for that by
making mesh reading and writing more expensive with conversions.

Resolves T85962

Differential Revision: https://developer.blender.org/D14365
2023-01-10 01:01:43 -05:00
Hans Goudey
1af62cb3bf Mesh: Move positions to a generic attribute
**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
2023-01-10 00:10:43 -05:00
Hans Goudey
d1d2946f59 Merge branch 'blender-v3.4-release' 2022-11-28 14:12:04 -06:00
Hans Goudey
745851e26b Fix T102772: Propagate edge creases in subdivision surface modifier
Before rBa8a454287a27, edge creases were copied to the result mesh as
part of `MEdge`. Now they are stored in a separate `CD_CREASE` layer,
which I mistakenly disabled for interpolation. However, to maintain
the geometry node uses a field input, remove the interpolated attribute
there.
2022-11-28 14:06:25 -06:00