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/******************************************************************************/
/*
Project - MudBun
Publisher - Long Bunny Labs
http://LongBunnyLabs.com
Author - Ming-Lun "Allen" Chou
http://AllenChou.net
*/
/******************************************************************************/
#pragma kernel dual_contouring_move_point
#pragma kernel dual_contouring_move_point_2d
#include "../../Shader/ComputeCommon.cginc"
#include "../../Shader/BrushFuncs.cginc"
#include "../../Shader/DualMeshingFuncs.cginc"
#include "../../Shader/GenPointDefs.cginc"
#include "../../Shader/IndirectArgsDefs.cginc"
#include "../../Shader/Math/MathConst.cginc"
#include "../../Shader/MeshingModeDefs.cginc"
#include "../../Shader/NormalFuncs.cginc"
#include "../../Shader/RenderModeDefs.cginc"
// https://www.boristhebrave.com/2018/04/15/dual-contouring-tutorial/
// https://www.mattkeeter.com/projects/contours/
float dualContouringDualQuadsBlend;
float dualContouringRelaxation;
int dualContouringSolverIterations;
int dualContouringBinarySearchIterations;
int dualContouringGradientDescentIterations;
float dualContouringGradientDescentFactor;
static int aEdgeVertIndex3d[12][2] =
{
{ 0, 1 },
{ 1, 5 },
{ 5, 4 },
{ 4, 0 },
{ 2, 3 },
{ 3, 7 },
{ 7, 6 },
{ 6, 2 },
{ 0, 2 },
{ 1, 3 },
{ 5, 7 },
{ 4, 6 },
};
static int aEdgeVertIndex2d[4][2] =
{
{ 0, 1 },
{ 1, 2 },
{ 2, 3 },
{ 3, 0 },
};
[numthreads(kThreadGroupSize, 1, 1)]
void dual_contouring_move_point(int3 id : SV_DispatchThreadID)
{
#if defined(MUDBUN_DISABLE_DUAL_CONTOURING) || defined(MUDBUN_FAST_ITERATION)
return;
#endif
if (id.x >= indirectDrawArgs[0])
return;
int iGenPoint = id.x;
if (dualContouringDualQuadsBlend >= 1.0f)
{
if (renderMode == kRenderModeQuadSplats)
aGenPoint[iGenPoint].material.size *= 0.70711f;
return;
}
float h = 0.5f * voxelSize;
float3 center = aGenPoint[iGenPoint].posNorm.xyz;
float3 minCornerOffset = -h;
int iBrushMask = aGenPoint[iGenPoint].iBrushMask;
float3 aCornerOffset[8] =
{
float3(-h, -h, -h),
float3( h, -h, -h),
float3(-h, h, -h),
float3( h, h, -h),
float3(-h, -h, h),
float3( h, -h, h),
float3(-h, h, h),
float3( h, h, h),
};
float aCornerRes[8];
SdfBrushMaterial mat;
[loop] for (int iCorner = 0; iCorner < 8; ++iCorner)
{
aCornerRes[iCorner] = sdf_masked_brushes(center + aCornerOffset[iCorner], iBrushMask, mat);
}
float3 avgEdgeOffset = 0.0f;
int numEdges = 0;
float3 aEdgeOffset[12];
[loop] for (int iEdge = 0; iEdge < 12; ++iEdge)
{
int iVert0 = aEdgeVertIndex3d[iEdge][0];
int iVert1 = aEdgeVertIndex3d[iEdge][1];
float res0 = aCornerRes[iVert0];
float res1 = aCornerRes[iVert1];
if (res0 * res1 > 0)
continue;
float3 offset0 = aCornerOffset[iVert0];
float3 offset1 = aCornerOffset[iVert1];
int iEdgeOutput = numEdges++;
float3 edgeOffset;
if (res0 == 0.0f && res1 == 0.0f)
{
edgeOffset = 0.5f * (offset0 + offset1);
}
else if (res0 == 0.0f)
{
edgeOffset = offset0;
}
else if (res1 == 0.0f)
{
edgeOffset = offset1;
}
else if (dualContouringBinarySearchIterations <= 0)
{
// lerp approximation
float t = -res0 / (res1 - res0);
edgeOffset = lerp(offset0, offset1, t);
}
else
{
// binary search
edgeOffset = 0.5f * (offset0 + offset1);
[loop] for (int iSearch = 0; iSearch < dualContouringBinarySearchIterations; ++iSearch)
{
float resT = sdf_masked_brushes(center + edgeOffset, iBrushMask, mat);
if (res0 * resT < 0.0f)
{
res1 = resT;
offset1 = edgeOffset;
}
else if (resT * res1 < 0.0f)
{
res0 = resT;
offset0 = edgeOffset;
}
edgeOffset = 0.5f * (offset0 + offset1);
}
}
avgEdgeOffset += edgeOffset;
aEdgeOffset[iEdgeOutput] = edgeOffset;
}
if (numEdges <= 0)
return;
avgEdgeOffset /= numEdges;
float3 aEdgeNorm[12];
[loop] for (int iEdgeOffset = 0; iEdgeOffset < numEdges; ++iEdgeOffset)
{
SDF_NORMAL_FULL(aEdgeNorm[iEdgeOffset], center + aEdgeOffset[iEdgeOffset], sdf_masked_brushes, iBrushMask, 1e-2f * voxelSize);
}
float3 bestOffset = 0.0f;
if (dualContouringSolverIterations > 0)
{
float aD[12];
for (int iEdgeOffset = 0; iEdgeOffset < numEdges; ++iEdgeOffset)
{
aD[iEdgeOffset] = dot(aEdgeNorm[iEdgeOffset], aEdgeOffset[iEdgeOffset]);
}
for (int iSolve = 0; iSolve < dualContouringSolverIterations; ++iSolve)
{
for (int iEdgeOffset = 0; iEdgeOffset < numEdges; ++iEdgeOffset)
{
bestOffset -= 0.75f * aEdgeNorm[iEdgeOffset] * dot(aEdgeNorm[iEdgeOffset], bestOffset - aEdgeOffset[iEdgeOffset]);
}
}
bestOffset = clamp(bestOffset, -h, h);
}
else
{
// minimize ||A * x - b||^2
float3x3 A[5];
float3 b[5];
for (int i = 0; i < 5; ++i)
{
A[i] = 0.0f;
b[i] = 0.0f;
}
{
int r = 0;
float dualContouringRelaxationComp = 1.0f - dualContouringRelaxation;
while (r < numEdges)
{
uint i = uint(r) / 3;
switch (uint(r) % 3)
{
case 0:
A[i]._m00_m01_m02 = dualContouringRelaxationComp * aEdgeNorm[r];
b[i].x = dualContouringRelaxationComp * dot(aEdgeNorm[r], aEdgeOffset[r]);
break;
case 1:
A[i]._m10_m11_m12 = dualContouringRelaxationComp * aEdgeNorm[r];
b[i].y = dualContouringRelaxationComp * dot(aEdgeNorm[r], aEdgeOffset[r]);
break;
case 2:
A[i]._m20_m21_m22 = dualContouringRelaxationComp * aEdgeNorm[r];
b[i].z = dualContouringRelaxationComp * dot(aEdgeNorm[r], aEdgeOffset[r]);
break;
}
++r;
}
A[4]._m00_m01_m02 = float3(dualContouringRelaxation, 0.0f, 0.0f);
A[4]._m10_m11_m12 = float3(0.0f, dualContouringRelaxation, 0.0f);
A[4]._m20_m21_m22 = float3(0.0f, 0.0f, dualContouringRelaxation);
b[4] = dualContouringRelaxation * avgEdgeOffset;
}
// pseudoinverse
{
float3x3 pInvA[5];
{
// tempA = (A' * A)^-1
float3x3 tempA = 0.0f;
for (int iA = 0; iA < 5; ++iA)
{
tempA += mul(transpose(A[iA]), A[iA]);
}
float3x3 tempACopy = tempA;
float det =
tempACopy._m00 * (tempACopy._m11 * tempACopy._m22 - tempACopy._m21 * tempACopy._m12) -
tempACopy._m01 * (tempACopy._m10 * tempACopy._m22 - tempACopy._m12 * tempACopy._m20) +
tempACopy._m02 * (tempACopy._m10 * tempACopy._m21 - tempACopy._m11 * tempACopy._m20);
float detInv = 1.0f / det;
tempA._m00 = (tempACopy._m11 * tempACopy._m22 - tempACopy._m21 * tempACopy._m12) * detInv;
tempA._m01 = (tempACopy._m02 * tempACopy._m21 - tempACopy._m01 * tempACopy._m22) * detInv;
tempA._m02 = (tempACopy._m01 * tempACopy._m12 - tempACopy._m02 * tempACopy._m11) * detInv;
tempA._m10 = (tempACopy._m12 * tempACopy._m20 - tempACopy._m10 * tempACopy._m22) * detInv;
tempA._m11 = (tempACopy._m00 * tempACopy._m22 - tempACopy._m02 * tempACopy._m20) * detInv;
tempA._m12 = (tempACopy._m10 * tempACopy._m02 - tempACopy._m00 * tempACopy._m12) * detInv;
tempA._m20 = (tempACopy._m10 * tempACopy._m21 - tempACopy._m20 * tempACopy._m11) * detInv;
tempA._m21 = (tempACopy._m20 * tempACopy._m01 - tempACopy._m00 * tempACopy._m21) * detInv;
tempA._m22 = (tempACopy._m00 * tempACopy._m11 - tempACopy._m10 * tempACopy._m01) * detInv;
// pInvA = (A' * A)^-1 * A' = tempA * A'
for (i = 0; i < 5; ++i)
{
pInvA[i] = mul(tempA, transpose(A[i]));
}
}
// bestOffset = pInvA * b
for (int iA = 0; iA < 5; ++iA)
{
bestOffset += mul(pInvA[iA], b[iA]);
}
} // end: pseudoinverse
}
float3 bestPos = center + bestOffset;
// doesn't buy us much and bloats compile time
// gradient descent
if (dualContouringGradientDescentIterations > 0)
{
float3 n;
SDF_NORMAL_FULL(n, bestPos, sdf_masked_brushes, iBrushMask, 1e-2f * voxelSize);
SdfBrushMaterial mat;
[loop] for (int iDescent = 0; iDescent < dualContouringGradientDescentIterations; ++iDescent)
{
float d = sdf_masked_brushes(bestPos, iBrushMask, mat);
bestOffset -= dualContouringGradientDescentFactor * n * d;
bestPos = center + bestOffset;
}
}
aGenPoint[iGenPoint].posNorm.xyz = lerp(bestPos, aGenPoint[iGenPoint].posNorm.xyz, dualContouringDualQuadsBlend);
if (renderMode == kRenderModeQuadSplats)
aGenPoint[iGenPoint].material.size *= 1.0f - (1.f - 0.70711f) * dualContouringDualQuadsBlend;
}
[numthreads(kThreadGroupSize, 1, 1)]
void dual_contouring_move_point_2d(int3 id : SV_DispatchThreadID)
{
#if defined(MUDBUN_DISABLE_DUAL_CONTOURING) || defined(MUDBUN_FAST_ITERATION)
return;
#endif
if (id.x >= indirectDrawArgs[0])
return;
int iGenPoint = id.x;
if (dualContouringDualQuadsBlend >= 1.0f)
{
if (renderMode == kRenderModeQuadSplats)
aGenPoint[iGenPoint].material.size *= 0.70711f;
return;
}
float h = 0.5f * voxelSize;
float3 center = aGenPoint[iGenPoint].posNorm.xyz;
float3 minCornerOffset = -h;
int iBrushMask = aGenPoint[iGenPoint].iBrushMask;
float3 aCornerOffset[4] =
{
float3(-h, -h, 0.0f),
float3(-h, h, 0.0f),
float3( h, h, 0.0f),
float3( h, -h, 0.0f),
};
bool anyOutside = false;
float aCornerRes[8];
SdfBrushMaterial mat;
[loop] for (int iCorner = 0; iCorner < 4; ++iCorner)
{
float cornerRes = sdf_masked_brushes(center + aCornerOffset[iCorner], iBrushMask, mat);
aCornerRes[iCorner] = cornerRes;
if (cornerRes >= 0.0f)
anyOutside = true;
}
if (!anyOutside)
return;
float3 avgEdgeOffset = 0.0f;
int numEdges = 0;
float3 aEdgeOffset[4];
[loop] for (int iEdge = 0; iEdge < 4; ++iEdge)
{
int iVert0 = aEdgeVertIndex2d[iEdge][0];
int iVert1 = aEdgeVertIndex2d[iEdge][1];
float res0 = aCornerRes[iVert0];
float res1 = aCornerRes[iVert1];
if (res0 * res1 > 0)
continue;
float3 offset0 = aCornerOffset[iVert0];
float3 offset1 = aCornerOffset[iVert1];
int iEdgeOutput = numEdges++;
float3 edgeOffset;
if (res0 == 0.0f && res1 == 0.0f)
{
edgeOffset = 0.5f * (offset0 + offset1);
}
else if (res0 == 0.0f)
{
edgeOffset = offset0;
}
else if (res1 == 0.0f)
{
edgeOffset = offset1;
}
else if (dualContouringBinarySearchIterations <= 0)
{
// lerp approximation
float t = -res0 / (res1 - res0);
edgeOffset = lerp(offset0, offset1, t);
}
else
{
// binary search
edgeOffset = 0.5f * (offset0 + offset1);
[loop] for (int iSearch = 0; iSearch < dualContouringBinarySearchIterations; ++iSearch)
{
float resT = sdf_masked_brushes(center + edgeOffset, iBrushMask, mat);
if (res0 * resT < 0.0f)
{
res1 = resT;
offset1 = edgeOffset;
}
else if (resT * res1 < 0.0f)
{
res0 = resT;
offset0 = edgeOffset;
}
edgeOffset = 0.5f * (offset0 + offset1);
}
}
avgEdgeOffset += edgeOffset;
aEdgeOffset[iEdgeOutput] = edgeOffset;
}
if (numEdges <= 0)
return;
avgEdgeOffset /= numEdges;
float3 aEdgeNorm[4];
[loop] for (int iEdgeOffset = 0; iEdgeOffset < numEdges; ++iEdgeOffset)
{
SDF_NORMAL_2D(aEdgeNorm[iEdgeOffset], center + aEdgeOffset[iEdgeOffset], sdf_masked_brushes, iBrushMask, 1e-2f * voxelSize);
}
// minimize ||A * x - b||^2
float2x2 A[3];
float2 b[3];
for (int i = 0; i < 3; ++i)
{
A[i] = 0.0f;
b[i] = 0.0f;
}
{
int r = 0;
float dualContouringRelaxationComp = 1.0f - dualContouringRelaxation;
while (r < numEdges)
{
uint i = uint(r) / 2;
switch (uint(r) % 2)
{
case 0:
A[i]._m00_m01 = dualContouringRelaxationComp * aEdgeNorm[r].xy;
b[i].x = dualContouringRelaxationComp * dot(aEdgeNorm[r], aEdgeOffset[r]);
break;
case 1:
A[i]._m10_m11 = dualContouringRelaxationComp * aEdgeNorm[r].xy;
b[i].y = dualContouringRelaxationComp * dot(aEdgeNorm[r], aEdgeOffset[r]);
break;
}
++r;
}
A[2]._m00_m01 = float2(dualContouringRelaxation, 0.0f);
A[2]._m10_m11 = float2(0.0f, dualContouringRelaxation);
b[2] = dualContouringRelaxation * avgEdgeOffset.xy;
}
float2 bestOffset = 0.0f;
// pseudoinverse
{
float2x2 pInvA[3];
{
// tempA = (A' * A)^-1
float2x2 tempA = 0.0f;
for (int iA = 0; iA < 3; ++iA)
{
tempA += mul(transpose(A[iA]), A[iA]);
}
float2x2 tempACopy = tempA;
float det = tempACopy._m00 * tempACopy._m11 - tempACopy._m01 * tempACopy._m10;
float detInv = 1.0f / det;
tempA._m00 = tempACopy._m11 * detInv;
tempA._m01 = -tempACopy._m01 * detInv;
tempA._m10 = -tempACopy._m10 * detInv;
tempA._m11 = tempACopy._m00 * detInv;
// pInvA = (A' * A)^-1 * A' = tempA * A'
for (i = 0; i < 3; ++i)
{
pInvA[i] = mul(tempA, transpose(A[i]));
}
}
// bestOffset = pInvA * b
for (int iA = 0; iA < 3; ++iA)
{
bestOffset += mul(pInvA[iA], b[iA]);
}
} // end: pseudoinverse
float3 bestPos = center + float3(bestOffset, 0.0f);
// doesn't buy us much and bloats compile time
// gradient descent
if (dualContouringGradientDescentIterations > 0)
{
float3 n;
SDF_NORMAL_2D(n, bestPos, sdf_masked_brushes, iBrushMask, 1e-2f * voxelSize);
SdfBrushMaterial mat;
[loop] for (int iDescent = 0; iDescent < dualContouringGradientDescentIterations; ++iDescent)
{
float d = sdf_masked_brushes(bestPos, iBrushMask, mat);
bestOffset -= 0.5f * dualContouringGradientDescentFactor * n.xy * d;
bestPos = center + float3(bestOffset, 0.0f);
}
}
aGenPoint[iGenPoint].posNorm.xyz = lerp(bestPos, aGenPoint[iGenPoint].posNorm.xyz, dualContouringDualQuadsBlend);
aGenPoint[iGenPoint].sdfValue = sdf_masked_brushes(bestPos, iBrushMask, mat) + surfaceShift;
if (renderMode == kRenderModeQuadSplats)
aGenPoint[iGenPoint].material.size *= 1.0f - (1.f - 0.70711f) * dualContouringDualQuadsBlend;
}