This change restores the use of 4-bits in Far::PatchParam to
encode the refinement level of a patch. This restores one bit
that was stolen to allow for more general encoding of boundary
edge and transition edge masks. In order to accommodate all
of the bits that are required, the transition edge mask bits
are now stored along with the faceId bits.
Also, accessors are now exposed directly as members of Far::PatchParam
and the internal bitfield class is no longer directly exposed.
Unified transition patch drawing affects the calculation of
tessellation level metrics. Because a single edge of a shader
patch might be split into two halfs along a transition edge,
the effective maximum number of spans along any adaptive edge
is limited to half of the device maximum.
Besides we've not been computing accurate derivatives on gregory patch,
there was a separate bug in shaders which gives completely bogus dUdV on
corner vertices. This change fixes that significant artifact, however,
is still approximating derivatives by ignoring rational components.
- add HLSL equivalents of the previous GLSL change
- rename OsdGetSingleCreaseSegmentParameter to
OsdGetPatchSingleCreaseSegmentParameter.
- add shadingMode UI for dxViewer similar to glViewer
use boundaryMask to identify the crease edge from 4 edges.
with this change, single-crease patch no longer needs to be rotated on
its population.
In shader, experimentally use same infinite sharp matrix for both
boundary and single-crease patch.
Added a size specifier to the shader output array declaration
in the GregoryBasis and Gregory control shaders. This seems
to be required by the GLSL compiler on AMD and is harmless elsewhere.
Added a size specifier to the shader output array declaration
in the BSpline control shader. This seems to be required by the
GLSL compiler on AMD and is harmless elsewhere.
This change refactors the GLSL and HLSL patch shader code so that
most of the work is implemented within a library of common functions
and the remaining shader snippets just manage plumbing.
There is more to do here:
- varying and face-varying data can be managed entirely by the client
- similarly, displacement can be implemented in client code
- there's still quite a bit of residual boiler-plate code needed
in each shader stage that we should be able to wrap up in a more
convenient form.
To encapsulate endcap functions from public API, add methods to
tell the number of patch points needed (GetNumLocalPoints()) and
to compute those patch points as a result of change of basis from
the refined vertices (ComputeLocalPointValues()).
ComputeLocalPointValues takes contiguous source data of all levels
including level0 control vertices.
It looks like there's a compiler bug in some earlier nvidia driver 340/346 releases.
It has been fixed in 348.07 (win) as far as I can tell.
Following code behaves incorrectly.
void f(int a) {
for (int i=0; i<3; ++i) doSomething(a, i);
}
void g() {
for (int i=0; i<100; ++i) f(i);
}
The workaround is to use different identifiers for each function.
Add EvalStencils and EvalPatches API for most of CPU and GPU evaluators.
with this change, Eval API in the osd layer consists of following parts:
- Evaluators (Cpu, Omp, Tbb, Cuda, CL, GLXFB, GLCompute, D3D11Compute)
implements EvalStencils and EvalPatches(*). Both supports derivatives
(not fully implemented though)
- Interop vertex buffer classes (optional, same as before)
Note that these classes are not necessary to use Evaluators.
All evaluators have EvalStencils/Patches which take device-specific
buffer objects. For example, GLXFBEvaluator can take GLuint directly
for both stencil tables and input primvars. Although using these
interop classes makes it easy to integrate osd into relatively
simple applications.
- device-dependent StencilTable and PatchTable (optional)
These are also optional, but can be used simply a substitute of
Far::StencilTable and Far::PatchTable for osd evaluators.
- PatchArray, PatchCoord, PatchParam
They are tiny structs used for GPU based patch evaluation.
(*) TODO and known issues:
- CLEvaluator and D3D11Evaluator's EvalPatches() have not been implemented.
- GPU Gregory patch evaluation has not been implemented in EvalPatches().
- CudaEvaluator::EvalPatches() is very unstable.
- All patch evaluation kernels have not been well optimized.
- Currently GLXFB kernel doesn't support derivative evaluation.
There's a technical difficulty for the multi-stream output.
- it takes number and pointer for the input PatchCoords.
- add derivative evaluations.
- enhance glEvalLimit example to see the derivative evaluation works.
Cleaned up the Legacy Gregory shader source by accessing buffer
data through helper functions.
Switched to performing tessellation in untransformed (object) space.
In osd layer, we use GLPatchTable (D3D11PatchTable) as a
device-specific representation of FarPatchTables instead of
DrawContext. GLPatchTable may be used not only for drawing
but also for GPU eval APIs (not yet supported though.
We may add CudaPatchTable etc as needed).
The legacy gregory patch drawing buffers are carved out to
the separate class, named GLLegacyGregoryPatchTable.
Also face-varying data are split into client side for now, until
we add new and more robust face-varying drawing structure
(scheduled at 3.1 release)
Tentatively replicate PatchArray structure in GLPatchTables. It will
be revised in the upcoming change.
Shifting hard-coded SRV locations of legacy gregory buffers in HLSL shaders.
- changes completely deprecate AddWithWeight(T, float, float, float)
- added new EvaluateBasis() method to PatchTables
- replaced usage of old Evaluate...<T,U>() methods with EvaluateBasis()
- removed old Evaluate...<T,U>() methods
- removed now unused Interpolate...<T,U>() functions in far/interpolate.h
- moved low-level basis code from far/interpolate.* to patchBasis.*
hlslPatchGregoryBasis.hlsl is an equivalent to glslPatchGregoryBasis.
Update dxViewer to be able to switch among bspline, gregorybasis, legacy
end capping.
also fixes a bug of GLSL legacy gregory shader which had an inconsistent
resource naming with example codes.
It looks like there's still an issue of D3D11 patchParam data fetching.
we'll come back to that bug.
While this may be worth revisiting, we should first quantify the benefits and
identify the compilers that support it. Ultimately, we may never use pragma
once in favor of strictly using standard C++.
As a preparation for retiring DrawContext, move SupportsAdaptiveTessellation
method to examples/common/glUtils, which is renamed and namespaced
from gl_common.{cpp,h} to be consistent to other files.
Same renamings applied to other example files.
Remove DrawRegistry from osd layer and put a simple shader caching
utility into examples/common. osd layer only provides patch shader
snippet and let client configure and compile the code. Clients also
maintain the lifetime of shader object, which is preferable for the
actual application integration.
update all examples to use the new scheme.
These are now redundant since all bspline patches are encoded in
the patch tables consistently using 16 point indices with boundary
and corner edges indicated in the boundary mask of the patch params.
Since unified shading work already removed subPatch info from
Osd::PatchDescriptor, the difference between Far::PatchDescriptor and
Osd::PatchDescriptor is just maxValence and numElements. They are used
for legacy gregory patch drawing.
Both maxValence and numElements are actually constant within a topology
(drawContext). This change move maxValence to DrawContext and let client
manage numElements, then we can eliminate Osd::PatchDescriptor and simply
use Far::PatchDescritor instead.
This is still an intermediate step toward further DrawRegistry refactoring.
For the time being, adding EffectDesc struct to include maxValence and
numValence to be maintained by the clients. They will be cleaned up later.
The side benefit of this change is we no longer need to recompile regular b-spline
shaders for the different max-valences.
- Remove MeshPtexData bit from Osd::MeshBits. It's not used any more
- Rename ptexIndexBuffer in D3D11DrawContext to paramParamBuffer
- Remove Is/SetPtexEnabled from D3D11DrawRegistry
In OpenSubdiv 2.x, we encapsulated subdivision tables into
compute context in osd layer since those tables are order-dependent
and have to be applied in a certain manner. In 3.0, we adopted stencil
table based refinement. It's more simple and such an encapsulation is
no longer needed. Also 2.0 API has several ownership issues of GPU
kernel caching, and forces unnecessary instantiation of controllers
even though the cpu kernels typically don't need instances unlike GPU ones.
This change completely revisit osd client facing APIs. All contexts and
controllers were replaced with device-specific tables and evaluators.
While we can still use consistent API across various device backends,
unnecessary complexities have been removed. For example, cpu evaluator
is just a set of static functions and also there's no need to replicate
FarStencilTables to ComputeContext.
Also the new API delegates the ownership of compiled GPU kernels
to clients, for the better management of resources especially in multiple
GPU environment.
In addition to integrating ComputeController and EvalStencilController into
a single function Evaluator::EvalStencils(), EvalLimit API is also added
into Evaluator. This is working but still in progress, and we'll make a followup
change for the complete implementation.
-some naming convention changes:
GLSLTransformFeedback to GLXFBEvaluator
GLSLCompute to GLComputeEvaluator
-move LimitLocation struct into examples/glEvalLimit.
We're still discussing patch evaluation interface. Basically we'd like
to tease all ptex-specific parametrization out of far/osd layer.
TODO:
-implments EvalPatches() in the right way
-derivative evaluation API is still interim.
-VertexBufferDescriptor needs a better API to advance its location
-synchronization mechanism is not ideal (too global).
-OsdMesh class is hacky. need to fix it.
