A bit work in progress, currently the following limitations:
- Texture shading only, Material shading will come later
- No UVs subdivision yet
- Always uses active UV and currently changing active UV will
not properly update the viewport.
Well, need to start somewhere :)
This is really similar to what GPU module was already doing. There are number of
possible improvements still:
- Re-use allocated VAOs when requesting new ones instead of going to the trouble
of freeing VAO and then re-creating it again.
- Move VAO handling to GPU module.
Fixes T46589: OpenSubdiv crash with drivers
Make it so CCGDM reports 0 number of geometry when it uses GPU backend for
drawing. This screws up a bit statistics in info header and requires to have
some special handle of CCGDM in the drawing code, but makes it so non of the
areas will try to access non-existing geometry.
The idea of this commit is to make it so we can enable OpenSubdiv by default
for the release builds but keep it limited to the viewport only for a specific
meshes. This is a temporary solution for until all the needed features are
supported on the OpenSubdiv side.
Flag itself is done as a dedicated field in modifier DNA so we can easily
remove it in the future without ending up with some temporary flag hanging
around forever.
The issue was caused by CCG code being confused by number of geometry returned
by utility functions in the case of the skipped grids.
Made it so that code is always only working with CCG data and handled drawing
code in a bit special way now.
This solves such crashes as i.e. snapping.
This commit contains all the remained parts needed for initial integration of
OpenSubdiv into Blender's subdivision surface code. Includes both GPU and CPU
backends which works in the following way:
- When SubSurf modifier is the last in the modifiers stack then GPU pipeline
of OpenSubdiv is used, making viewport performance as fast as possible.
This also requires graphscard with GLSL 1.5 support. If this requirement is
not met, then no GPU pipeline is used at all.
- If SubSurf is not a last modifier or if DerivesMesh is being evaluated for
rendering then CPU limit evaluation API from OpenSubdiv is used. This only
replaces the legacy evaluation code from CCGSubSurf_legacy, but keeps CCG
structures exactly the same as they used to be for ages now.
This integration is fully covered with ifdef and not enabled by default
because there are several TODOs to be solved first:
- Face varying data interpolation is not really cleanly implemented for GPU
in OpenSubdiv 3.0. It is also not implemented for limit evaluation API.
This basically means we'll have really hard time supporting UVs.
- Limit evaluation only works with adaptivly subdivided meshes so far, which
basically means all the points of CCG are pushed to the limit. This gives
different result from old code.
- There are some serious optimizations possible on the topology refiner
creation, which would speed up initial OpenSubdiv mesh creation.
- There are some hardcoded asumptions in the GPU and DerivedMesh areas which
could be generalized.
That's something where Antony and Campbell can help, making it so the code
is structured in a way which is reusable by all planned viewport projects.
- There are also some workarounds in the dependency graph to make sure OpenGL
buffers are only freed from the main thread.
Those who'll be wanting to make experiments with this code should grab dev
branch (NOT master) from
https://github.com/Nazg-Gul/OpenSubdiv/tree/dev
There are some patches applied in there which we're working on on getting
into upstream.
This is a preparation commit for having OpenSubdiv integrated into Blender
and new layout is the following:
- CCGSubSurf.c contains implementation of common functions used by both
legacy subdivisions code and by the new code in the future.
- CCGSubSurf_inline.h contains internal functions which are to be inlined
due to the performance reasons. Those functions are only ment to be used
bu CCGSubSurf* files.
- CCGSubSurf_intern.h contains declarations of private functions and data
structures used by CCGSubSurf module.
- CCGSubSurf_legacy.c contains legacy implementation of subdivision algorithm.
- CCHSubSurf_util.c contains utility functions which are not directly related
on the subdivision code (i.e. debug functions, hash implementation etc).
There should be no functional changes so far.
Our new guarded allocator implementation has much smaller memory
block size overhead and doesn't have any locks now. So in order
to make fuller track of what's happening in blender and avoid
confusion why certain circumstances reports much less memory than
others we'll now switch to guarded allocator.
This was actually one of the biggest reasons of the confusion in
the recent memory usage investigation. There's still some overhead
is happening due to non-freeing nature of arena allocator but the
things are not nearly as bad as they looked before: memory overhead
is measured in tens of megabytes, not hundreds as it looked before.
Plus with some smarter allocation policy we can almost eliminate this
overhead.
Allocating the iterator from a BLI_memarena wasn't threadsafe.
Change the API to use stack memory for iterators.
Thanks to @mont29 for finding exact cause of the bug.
Subsurf on wire edges gave smooth results even if set to simple
subdiv. Added a field to the CCG meshIFC to flag simple subdivision,
then when syncing vertices simply skip moving vertices if in
simple-subdiv mode.
This change affects two places, the level-1 build in sync and the
subdivision up to other levels.
Fixes bug [#32268] Simple Subsurf Modifier gives unexpected results on
edges without faces
projects.blender.org/tracker/index.php?func=detail&aid=32268&group_id=9&atid=498
Changed the "exterior edge interior shift" section of subsurf calc to
always treat boundary edges the same, regardless of sharpness. We
should revisit subsurf creasing to see if more consistent and
predictable results are possible, but for now this a non-intrusive way
to avoid wavyness along the boundary.
Fixes bug [#31864] Artifacts when using Subsurf+Crease on plane
http://projects.blender.org/tracker/index.php?func=detail&aid=31864&group_id=9&atid=498
* Add new CCG function ccgSubSurf_setAllocMask(). Similar to to
ccgSubSurf_setCalcVertexNormals(), it sets whether the CCG elements
have a mask layer and what that layer's offset is. Unlike normals
however, it doesn't change any behavior during CCG calculation; it's
there only to give CCGKey information on the mask.
* Add a new flag to _getSubSurf(), CCG_ALLOC_MASK. If set, space for
an extra layer is allocated, but the number of CCG layers is not set
to include it. This is done because GridPaintMasks are absolute,
rather than being relative to the subdivided output (as MDisp
displacements are), so we skip subdividing paint masks here.
* Add a new flag to subsurf_make_derived_from_derived(),
SUBSURF_ALLOC_PAINT_MASK. This controls whether CCG_ALLOC_MASK is
set for _getSubSurf(). Related, masks are never loaded in during
ss_sync_from_derivedmesh(). After subdivision is finished, if the
alloc mask flag is set, the number of CCG layers is increase to 4
with ccgSubSurf_setNumLayers().
* Add a new flag to multires_make_from_derived(),
MULTIRES_ALLOC_PAINT_MASK. Not all multires functions need paint
mask data (e.g. multiresModifier_base_apply.) This flag is always
set in MOD_multires.c so that subdividing a mesh with a mask updates
properly even when not in sculpt mode.
* Update multiresModifier_disp_run() to apply, calculate, and add mask
elements. It's almost the same as the existing operations with xyz
coordinates, but treats masks as absolute rather than displacements
relative to subdivided values.
* Update multires_customdata_delete to free CD_GRID_PAINT_MASK in
addition to CD_MDISPS.
* Update multires_del_higher() to call the new function
multires_grid_paint_mask_downsample(), which allocates a
lower-resolution paint mask grid and copies values over from the
high-resolution grid.
CCGKey caches information about the CCGSubSurf element layout. This
data, along with the CCG_* inline functions, allows access to
CCGSubSurf elements with an arbitrary number of layers (as opposed to
the hardcoded DMGridData structure which assumes xyz coordinates
followed by three normal components.)
The CCGElem structure is declared but not defined anywhere, just used
as a convenient type.
The layout of vert data in CCGSubSurf is almost the same; previously
it was three floats (for xyz coordinate) optionally followed by three
floats for the normal. The only change is that the first three floats
can now be any number of floats.
* _getSubSurf takes a numLayers parameter to set the number of layers,
stored in CCGMeshIFC.numLayers.
* All calls to _getSubSurf currently have numLayers set to 3, except
for UV subsurf, where it is reduced to 2 (with a corresponding
change when reading the results out to use float (*)[2] rather than
float (*)[3].)
* The various VertData* macros in CCGSubSurf.c are now functions that
take a CCGSubSurf pointer, which provides access to CCGMeshIFC,
which has numLayers.
* Add ccgSubSurf_setNumLayers() to the API. Only changes the number of
layers that get subdivided, doesn't change the amount of memory
allocated. So if space for N layers is allocated, it's safe to set
the number of layers to less than N, but not more.
* The rest of the changes are just adding the 'ss' parameter.
