OpenSubdiv/opensubdiv/osd/hlslPatchBoxSplineTriangle.hlsl
David G Yu 67cc2a3810 Irregular patch shader transition edges
Updated the Gregory patch tessellation shaders to account for
transition edges.

Changed the implementation of OsdGetTessParameterizationTriangle()
to take the input parametric location as a 3-component value. This
allows the edge parameterization to be more numerically robust and
consistent.

Also, corrected some minor discrepancies between the various
tessellation shader configurations.
2019-06-03 15:34:40 -07:00

148 lines
4.9 KiB
HLSL

//
// Copyright 2019 Pixar
//
// Licensed under the Apache License, Version 2.0 (the "Apache License")
// with the following modification; you may not use this file except in
// compliance with the Apache License and the following modification to it:
// Section 6. Trademarks. is deleted and replaced with:
//
// 6. Trademarks. This License does not grant permission to use the trade
// names, trademarks, service marks, or product names of the Licensor
// and its affiliates, except as required to comply with Section 4(c) of
// the License and to reproduce the content of the NOTICE file.
//
// You may obtain a copy of the Apache License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the Apache License with the above modification is
// distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. See the Apache License for the specific
// language governing permissions and limitations under the Apache License.
//
//----------------------------------------------------------
// Patches.VertexBoxSplineTriangle
//----------------------------------------------------------
void vs_main_patches( in InputVertex input,
out HullVertex output )
{
output.position = input.position;
OSD_PATCH_CULL_COMPUTE_CLIPFLAGS(input.position);
}
//----------------------------------------------------------
// Patches.HullBoxSplineTriangle
//----------------------------------------------------------
[domain("tri")]
[partitioning(OSD_PARTITIONING)]
[outputtopology("triangle_cw")]
[outputcontrolpoints(15)]
[patchconstantfunc("HSConstFunc")]
OsdPerPatchVertexBezier hs_main_patches(
in InputPatch<HullVertex, 12> patch,
uint primitiveID : SV_PrimitiveID,
in uint ID : SV_OutputControlPointID )
{
OsdPerPatchVertexBezier output;
float3 cv[12];
for (int i=0; i<12; ++i) {
cv[i] = patch[i].position.xyz;
}
int3 patchParam = OsdGetPatchParam(OsdGetPatchIndex(primitiveID));
OsdComputePerPatchVertexBoxSplineTriangle(patchParam, ID, cv, output);
return output;
}
HS_CONSTANT_FUNC_TRIANGLE_OUT
HSConstFunc(
InputPatch<HullVertex, 12> patch,
OutputPatch<OsdPerPatchVertexBezier, 15> bezierTrianglePatch,
uint primitiveID : SV_PrimitiveID)
{
HS_CONSTANT_FUNC_TRIANGLE_OUT output;
int3 patchParam = OsdGetPatchParam(OsdGetPatchIndex(primitiveID));
float4 tessLevelOuter = float4(0,0,0,0);
float2 tessLevelInner = float2(0,0);
float4 tessOuterLo = float4(0,0,0,0);
float4 tessOuterHi = float4(0,0,0,0);
OSD_PATCH_CULL_TRIANGLE(12);
#if defined OSD_ENABLE_SCREENSPACE_TESSELLATION
float3 bezcv[15];
for (int i=0; i<15; ++i) {
bezcv[i] = bezierTrianglePatch[i].P;
}
OsdEvalPatchBezierTriangleTessLevels(bezcv, patchParam,
tessLevelOuter, tessLevelInner,
tessOuterLo, tessOuterHi);
#else
OsdGetTessLevelsUniformTriangle(patchParam, tessLevelOuter, tessLevelInner,
tessOuterLo, tessOuterHi);
#endif
output.tessLevelOuter[0] = tessLevelOuter[0];
output.tessLevelOuter[1] = tessLevelOuter[1];
output.tessLevelOuter[2] = tessLevelOuter[2];
output.tessLevelInner[0] = tessLevelInner[0];
output.tessOuterLo = tessOuterLo;
output.tessOuterHi = tessOuterHi;
return output;
}
//----------------------------------------------------------
// Patches.DomainBoxSplineTriangle
//----------------------------------------------------------
[domain("tri")]
void ds_main_patches(
in HS_CONSTANT_FUNC_TRIANGLE_OUT input,
in OutputPatch<OsdPerPatchVertexBezier, 15> patch,
in float3 domainCoord : SV_DomainLocation,
out OutputVertex output )
{
float3 P = float3(0,0,0), dPu = float3(0,0,0), dPv = float3(0,0,0);
float3 N = float3(0,0,0), dNu = float3(0,0,0), dNv = float3(0,0,0);
OsdPerPatchVertexBezier cv[15];
for (int i=0; i<15; ++i) {
cv[i] = patch[i];
}
float2 UV = OsdGetTessParameterizationTriangle(domainCoord,
input.tessOuterLo,
input.tessOuterHi);
int3 patchParam = patch[0].patchParam;
OsdEvalPatchBezierTriangle(patchParam, UV, cv, P, dPu, dPv, N, dNu, dNv);
// all code below here is client code
output.position = mul(OsdModelViewMatrix(), float4(P, 1.0f));
output.normal = mul(OsdModelViewMatrix(), float4(N, 0.0f)).xyz;
output.tangent = mul(OsdModelViewMatrix(), float4(dPu, 0.0f)).xyz;
output.bitangent = mul(OsdModelViewMatrix(), float4(dPv, 0.0f)).xyz;
#ifdef OSD_COMPUTE_NORMAL_DERIVATIVES
output.Nu = dNu;
output.Nv = dNv;
#endif
output.patchCoord = OsdInterpolatePatchCoordTriangle(UV, patchParam);
OSD_DISPLACEMENT_CALLBACK;
output.positionOut = mul(OsdProjectionMatrix(), output.position);
output.edgeDistance = 0;
}