The evaluated mesh is a result of evaluated modifiers, and referencing
other evaluated IDs such as materials.
It can not be stored in the EditMesh structure which is intended to be
re-used by many areas. Such sharing was causing ownership errors causing
bugs like
T93855: Cycles crash with edit mode and simultaneous viewport and final render
The proposed solution is to store the evaluated edit mesh and its cage in
the object's runtime field. The motivation goes as following:
- It allows to avoid ownership problems like the ones in the linked report.
- Object level is chosen over mesh level is because the evaluated mesh
is affected by modifiers, which are on the object level.
This patch allows to have modifier stack of an object which shares mesh with
an object which is in edit mode to be properly taken into account (before
the change the modifier stack from the active object will be used for all
objects which share the mesh).
There is a change in the way how copy-on-write is handled in the edit mode to
allow proper state update when changing active scene (or having two windows
with different scenes). Previously, the copt-on-write would have been ignored
by skipping tagging CoW component. Now it is ignored from within the CoW
operation callback. This allows to update edit pointers for objects which are
not from the current depsgraph and where the edit_mesh was never assigned in
the case when the depsgraph was evaluated prior the active depsgraph.
There is no user level changes changes expected with the CoW handling changes:
should not affect on neither performance, nor memory consumption.
Tested scenarios:
- Various modifiers configurations of objects sharing mesh and be part of the
same scene.
- Steps from the reports: T93855, T82952, T77359
This also fixes T76609, T72733 and perhaps other reports.
Differential Revision: https://developer.blender.org/D13824
As described in T91186, this commit moves mesh vertex normals into a
contiguous array of float vectors in a custom data layer, how face
normals are currently stored.
The main interface is documented in `BKE_mesh.h`. Vertex and face
normals are now calculated on-demand and cached, retrieved with an
"ensure" function. Since the logical state of a mesh is now "has
normals when necessary", they can be retrieved from a `const` mesh.
The goal is to use on-demand calculation for all derived data, but
leave room for eager calculation for performance purposes (modifier
evaluation is threaded, but viewport data generation is not).
**Benefits**
This moves us closer to a SoA approach rather than the current AoS
paradigm. Accessing a contiguous `float3` is much more efficient than
retrieving data from a larger struct. The memory requirements for
accessing only normals or vertex locations are smaller, and at the
cost of more memory usage for just normals, they now don't have to
be converted between float and short, which also simplifies code
In the future, the remaining items can be removed from `MVert`,
leaving only `float3`, which has similar benefits (see T93602).
Removing the combination of derived and original data makes it
conceptually simpler to only calculate normals when necessary.
This is especially important now that we have more opportunities
for temporary meshes in geometry nodes.
**Performance**
In addition to the theoretical future performance improvements by
making `MVert == float3`, I've done some basic performance testing
on this patch directly. The data is fairly rough, but it gives an idea
about where things stand generally.
- Mesh line primitive 4m Verts: 1.16x faster (36 -> 31 ms),
showing that accessing just `MVert` is now more efficient.
- Spring Splash Screen: 1.03-1.06 -> 1.06-1.11 FPS, a very slight
change that at least shows there is no regression.
- Sprite Fright Snail Smoosh: 3.30-3.40 -> 3.42-3.50 FPS, a small
but observable speedup.
- Set Position Node with Scaled Normal: 1.36x faster (53 -> 39 ms),
shows that using normals in geometry nodes is faster.
- Normal Calculation 1.6m Vert Cube: 1.19x faster (25 -> 21 ms),
shows that calculating normals is slightly faster now.
- File Size of 1.6m Vert Cube: 1.03x smaller (214.7 -> 208.4 MB),
Normals are not saved in files, which can help with large meshes.
As for memory usage, it may be slightly more in some cases, but
I didn't observe any difference in the production files I tested.
**Tests**
Some modifiers and cycles test results need to be updated with this
commit, for two reasons:
- The subdivision surface modifier is not responsible for calculating
normals anymore. In master, the modifier creates different normals
than the result of the `Mesh` normal calculation, so this is a bug
fix.
- There are small differences in the results of some modifiers that
use normals because they are not converted to and from `short`
anymore.
**Future improvements**
- Remove `ModifierTypeInfo::dependsOnNormals`. Code in each modifier
already retrieves normals if they are needed anyway.
- Copy normals as part of a better CoW system for attributes.
- Make more areas use lazy instead of eager normal calculation.
- Remove `BKE_mesh_normals_tag_dirty` in more places since that is
now the default state of a new mesh.
- Possibly apply a similar change to derived face corner normals.
Differential Revision: https://developer.blender.org/D12770
- 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
Adding a mirror modifier in edit-mode crashed.
Freeing meshes that hold a shallow copy happens in multiple places
while calculating modifiers, making it impractical to clear the
edit-mode pointer before freeing the mesh (as done in
BKE_editmesh_free_derived_caches).
Add a struct member to the edit-mesh struct so evaluated copies
don't free the edit-mesh contents.
Freeing the edit-mesh pointer wasn't free the edit-mesh data it's self.
Unlinking from the outliner or through the Python API leaked memory.
This didn't often cause leaks in practice since ED_editors_exit
exits edit-mode for all objects.
Now freeing mesh data frees the edit-mode data as well,
this matches the behavior of other object types that support edit-mode.
Rename:
- EDBM_mesh_free -> EDBM_mesh_free_data
BKE_editmesh_free -> BKE_editmesh_free_data
Since this doesn't free the edit-mesh pointer.
- BKE_editmesh_free_derivedmesh -> BKE_editmesh_free_derived_caches
Since this no longer uses derived-mesh, match naming for the related
object function BKE_object_free_derived_caches.
Also remove `do_tessellate` argument from BKE_editmesh_create,
since the caller can explicitly do this if it's needed,
with the advantage that it can be combined with normal calculation
which is faster on high-poly meshes.
Support calculating face normals when tessellating. When this is done
before updating vertex normals it gives ~20% performance improvement.
Now vertex normal calculation only needs to perform a single pass on the
mesh vertices when called after tessellation.
Extended versions of normal & looptri update functions have been added:
- BM_mesh_calc_tessellation_ex
- BM_mesh_normals_update_ex
Most callers don't need to be aware of this detail by using:
- BKE_editmesh_looptri_and_normals_calc
- BKE_editmesh_looptri_and_normals_calc_with_partial
- EDBM_update also takes advantage of this,
where calling EDBM_update with calc_looptri & calc_normals
enabled uses the faster normal updating logic.
This patch exposes functionality for performing partial mesh updates
for normal calculation and face tessellation while transforming a mesh.
The partial update data only needs to be generated once,
afterwards the cached connectivity information can be reused
(with the exception of changing proportional editing radius).
Currently this is only used for transform, in the future it could be
used for other operators as well as the transform panel.
The best-case overall speedup while transforming geometry is about
1.45x since the time to update a small number of normals and faces is
negligible.
For an additional speedup partial face tessellation is multi-threaded,
this gives ~15x speedup on my system (timing tessellation alone).
Exact results depend on the number of CPU cores available.
Ref D11494
Reviewed By: mano-wii
2 sided faces aren't supported and will cause problems in many areas
of Blender's code.
Removing (implied) support for faces with fewer than 3 sides
means the total number of triangles is known ahead of time.
This simplifies adding support for multi-threading and partial updates
to an existing tessellation - as the face and loop indices can be used
to access the range of triangles associated with a face.
Also correct outdated comments.
With constructive + deform modifiers, loop-cut visualization
wasn't following the displayed mesh.
This now gets the coordinates from the cage when available.
This resolves a performance regression in 2.8x where every edit-mode
update performed an edit-mesh to mesh conversion.
Now the conversion will be lazily initialized if/when it's required.
New BKE_mesh_wrapper_* functions abstract over mesh data access.
Currently only edit-mesh and regular meshes are supported.
In the future sub-surface meshes may be supported too.
Note that this is a bit clumsy having both edit-mesh and mesh,
BKE_editmesh_ensure_autosmooth & BKE_editmesh_lnorspace_update
are often called together, these could be made into a single functions.
BF-admins agree to remove header information that isn't useful,
to reduce noise.
- BEGIN/END license blocks
Developers should add non license comments as separate comment blocks.
No need for separator text.
- Contributors
This is often invalid, outdated or misleading
especially when splitting files.
It's more useful to git-blame to find out who has developed the code.
See P901 for script to perform these edits.
This makes the Edit Mesh display settings common to all objects. They can
also be set differently per viewport.
Modifying extra data (seams, sharp edges etc...) will no longer set them
automaticaly visible.
Bumping version because we need to force set all extra draw options for
older files.
This adds initial multi-object editing support.
- Selected objects are used when entering edit & pose modes.
- Selection & tools work on all objects however many tools need porting
See: T54641 for remaining tasks.
Indentation will be done separately.
See patch: D3101
