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.
Those files are still not in use (SCons will tyr to compile new CCGSubSurf files
but no code will be in use at all because those new files are fully wrapped by
ifdef WITH_OPENSUBDIV check).
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.
defvert_find_index() & co now assert when '-1' invalid vgroup index is passed.
We used to rely on NULL value returned in this case, but with the assert...
The assert completely stalls blender actually (repeated for every vertex!).
So much better to not call that func when vgroup index is invalid.
It was always only using the flags from the first source layer of a given type, not from
the layer actually being handled.
This was (probably) more or less harmless for the CD_FLAG_NOCOPY test,
but could be really bad when checking CD_FLAG_NOFREE, and when
copying the flags over to new copied data!
Several class member variables were removed (at the cost of computing their values
when retrieved) or changed to a type of smaller size. Also fixed whitespace.
There was possible race condition in the point density sampling caused
by access to the same data in particle system from sampling thread and
sampling initialization.
Could have happened when two different point density textures were using
same particle system
This commit implements point density texture for Cycles shading nodes.
It's done via creating voxel texture at shader compilation time, Not
totally memory efficient, but avoids adding sampling code to kernel
(which keeps render time as low as possible), In the future this will
be compensated by using OpenVDB for more efficient storage of sparse
volume data.
Sampling of the voxel texture is happening at blender side and the
same code is used as for Blender Internal's renderer.
This texture is controlled by only object, particle system and radius.
Linear falloff is used and there's no turbulence. This is because
falloff is expected to happen using Curve Mapping node. Turbulence
will be done as a distortion on the input coordinate. It's already
possible to fake it using nose textures and in the future we can add
more proper turbulence distortion node, which then could also be used
for 2D texture mapping.
Particle color support is done by Lukas, thanks!
Main issue in previous code was that you could not shift-alt-rmb select several
contiguous strips, result was pretty much unusable.
Also, enhanced general behavior of this selection mode, now (similar to alt-rm clicking
on handles), when you alt-rmb click on a same strip several times, you alternate between:
* Strip is selected, neighbor handles are selected;
* Strip and its handles are selected, neighbor handles are selected.
…which allows you to either grab or slide the strip.
And refactored a bit code too, linked_handle has a complete different logic
than without this option, simpler and clearer to completely separate them in code.
Initial issue reported by Leon Cheung on IRC, thanks!
