Previously the UV unwrapping handling for subsurf modifiers used
`DerivedMesh`to implement the subdivision. Since we're trying to remove
`DerivedMesh` in general, and since this just made use of the `Mesh`
data anyway, it's relatively simple to remove it here. Combined with
D15939, this makes it possible to remove more `DerivedMesh` code.
Differential Revision: https://developer.blender.org/D16487
Instancing with geometry nodes uses just the evaluated Mesh, and ignores the
Object that it came from. That meant that it would try to look up the subsurf
modifier on the instancer object which does not have the subsurf modifier.
Instead of storing a session UUID and looking up the modifier data, store a
point to the subsurf modifier runtime data. Unlike the modifier data, this
runtime data is preserved across depsgraph CoW. It must be for the subdiv
descriptor contained in it to stay valid along with the draw cache.
As a bonus, this moves various Mesh_Runtime variables into the subsurf runtime
data, reducing memory usage for meshes not using subdivision surfaces.
Also fixes T98693, issues with subdivision level >= 8 due to integer overflow.
Differential Revision: https://developer.blender.org/D15184
The problem is that depsgraph evaluation happens before the OpenGL context
is initialized, and so modifier evaluation happens without GPU subdivision.
Later the BKE_subsurf_modifier_can_do_gpu_subdiv test in the draw code gives
a different result.
This just checks if the mesh has information for GPU subdivision in the draw
code, and if so uses it. This is only set if the test for supported GPU
subdivision passes in the modifier evaluation.
Additionally it may be good to perform OpenGL context initialization earlier
so background render can take advantage of GPU subdivision, but this is more
complicated.
Differential Revision: https://developer.blender.org/D14969
Some old platforms and drivers have limited amount of SSBO binding per
compute shader. This disables GPU subdivision if we cannot possibly
bind all required buffers within this limit.
For now the maximum number of buffers used by the GPU code is hardcoded,
but will be programmatically detected when shader creation is automated.
Ref D14337
These features are complicated to support on GPU and hardly compatible
with subdivision in the first place. In the future, with T68891 and
T68893, subdivision and custom smooth shading will be separate workflows.
For now, and to better prepare for this future (although long term
plan), we should discourage workflows mixing subdivision and custom
smooth normals, and as such, this disables GPU subdivision when
autosmoothing or custom split normals are used.
This also adds a message in the modifier's UI to indicate that GPU
subdivision will be disabled if autosmooth or custom split normals are
used on the mesh.
Differential Revision: https://developer.blender.org/D14194
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
This evaluator is used in order to evaluate subdivision at render time, allowing for
faster renders of meshes with a subdivision surface modifier placed at the last
position in the modifier list.
When evaluating the subsurf modifier, we detect whether we can delegate evaluation
to the draw code. If so, the subdivision is first evaluated on the GPU using our own
custom evaluator (only the coarse data needs to be initially sent to the GPU), then,
buffers for the final `MeshBufferCache` are filled on the GPU using a set of
compute shaders. However, some buffers are still filled on the CPU side, if doing so
on the GPU is impractical (e.g. the line adjacency buffer used for x-ray, whose
logic is hardly GPU compatible).
This is done at the mesh buffer extraction level so that the result can be readily used
in the various OpenGL engines, without having to write custom geometry or tesselation
shaders.
We use our own subdivision evaluation shaders, instead of OpenSubDiv's vanilla one, in
order to control the data layout, and interpolation. For example, we store vertex colors
as compressed 16-bit integers, while OpenSubDiv's default evaluator only work for float
types.
In order to still access the modified geometry on the CPU side, for use in modifiers
or transform operators, a dedicated wrapper type is added `MESH_WRAPPER_TYPE_SUBD`.
Subdivision will be lazily evaluated via `BKE_object_get_evaluated_mesh` which will
create such a wrapper if possible. If the final subdivision surface is not needed on
the CPU side, `BKE_object_get_evaluated_mesh_no_subsurf` should be used.
Enabling or disabling GPU subdivision can be done through the user preferences (under
Viewport -> Subdivision).
See patch description for benchmarks.
Reviewed By: campbellbarton, jbakker, fclem, brecht, #eevee_viewport
Differential Revision: https://developer.blender.org/D12406
