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Add Model SDF generation utilities

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This commit is contained in:
Wojciech Figat
2022-03-24 11:32:02 +01:00
parent d5060e9067
commit b08d2001fd
24 changed files with 696 additions and 323 deletions
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305
Source/Engine/Tools/ModelTool/ModelTool.cpp
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@@ -3,7 +3,19 @@
#if COMPILE_WITH_MODEL_TOOL
#include "ModelTool.h"
#include "MeshAccelerationStructure.h"
#include "Engine/Core/Log.h"
#include "Engine/Core/RandomStream.h"
#include "Engine/Core/Math/Int3.h"
#include "Engine/Core/Math/Ray.h"
#include "Engine/Profiler/ProfilerCPU.h"
#include "Engine/Threading/JobSystem.h"
#include "Engine/Graphics/RenderTools.h"
#include "Engine/Graphics/Async/GPUTask.h"
#include "Engine/Graphics/Textures/TextureData.h"
#include "Engine/Content/Assets/Model.h"
#include "Engine/Serialization/MemoryWriteStream.h"
#if USE_EDITOR
#include "Engine/Core/Types/DateTime.h"
#include "Engine/Core/Types/TimeSpan.h"
#include "Engine/Core/Types/Pair.h"
@@ -19,6 +31,297 @@
#include "Engine/ContentImporters/CreateCollisionData.h"
#include "Editor/Utilities/EditorUtilities.h"
#include <ThirdParty/meshoptimizer/meshoptimizer.h>
#endif
ModelSDFHeader::ModelSDFHeader(const ModelBase::SDFData& sdf, const GPUTextureDescription& desc)
: LocalToUVWMul(sdf.LocalToUVWMul)
, WorldUnitsPerVoxel(sdf.WorldUnitsPerVoxel)
, LocalToUVWAdd(sdf.LocalToUVWAdd)
, MaxDistance(sdf.MaxDistance)
, LocalBoundsMin(sdf.LocalBoundsMin)
, MipLevels(desc.MipLevels)
, LocalBoundsMax(sdf.LocalBoundsMax)
, Width(desc.Width)
, Height(desc.Height)
, Depth(desc.Depth)
, Format(desc.Format)
, ResolutionScale(sdf.ResolutionScale)
, LOD(sdf.LOD)
{
}
ModelSDFMip::ModelSDFMip(int32 mipIndex, uint32 rowPitch, uint32 slicePitch)
: MipIndex(mipIndex)
, RowPitch(rowPitch)
, SlicePitch(slicePitch)
{
}
ModelSDFMip::ModelSDFMip(int32 mipIndex, const TextureMipData& mip)
: MipIndex(mipIndex)
, RowPitch(mip.RowPitch)
, SlicePitch(mip.Data.Length())
{
}
bool ModelTool::GenerateModelSDF(Model* inputModel, ModelData* modelData, float resolutionScale, int32 lodIndex, ModelBase::SDFData* outputSDF, MemoryWriteStream* outputStream, const StringView& assetName)
{
PROFILE_CPU();
auto startTime = Platform::GetTimeSeconds();
// Setup SDF texture properties
BoundingBox bounds;
if (inputModel)
bounds = inputModel->LODs[lodIndex].GetBox();
else if (modelData)
bounds = modelData->LODs[lodIndex].GetBox();
else
return true;
Vector3 size = bounds.GetSize();
ModelBase::SDFData sdf;
sdf.WorldUnitsPerVoxel = 10 / Math::Max(resolutionScale, 0.0001f);
Int3 resolution(Vector3::Ceil(Vector3::Clamp(size / sdf.WorldUnitsPerVoxel, 4, 256)));
Vector3 uvwToLocalMul = size;
Vector3 uvwToLocalAdd = bounds.Minimum;
sdf.LocalToUVWMul = Vector3::One / uvwToLocalMul;
sdf.LocalToUVWAdd = -uvwToLocalAdd / uvwToLocalMul;
sdf.MaxDistance = size.MaxValue();
sdf.LocalBoundsMin = bounds.Minimum;
sdf.LocalBoundsMax = bounds.Maximum;
sdf.ResolutionScale = resolutionScale;
sdf.LOD = lodIndex;
// TODO: maybe apply 1 voxel margin around the geometry?
const int32 maxMips = 3;
const int32 mipCount = Math::Min(MipLevelsCount(resolution.X, resolution.Y, resolution.Z, true), maxMips);
PixelFormat format = PixelFormat::R16_UNorm;
int32 formatStride = 2;
float formatMaxValue = MAX_uint16;
typedef float (*FormatRead)(void* ptr);
typedef void (*FormatWrite)(void* ptr, float v);
FormatRead formatRead = [](void* ptr)
{
return (float)*(uint16*)ptr;
};
FormatWrite formatWrite = [](void* ptr, float v)
{
*(uint16*)ptr = (uint16)v;
};
if (resolution.MaxValue() < 8)
{
// For smaller meshes use more optimized format (gives small perf and memory gain but introduces artifacts on larger meshes)
format = PixelFormat::R8_UNorm;
formatStride = 1;
formatMaxValue = MAX_uint8;
formatRead = [](void* ptr)
{
return (float)*(uint8*)ptr;
};
formatWrite = [](void* ptr, float v)
{
*(uint8*)ptr = (uint8)v;
};
}
GPUTextureDescription textureDesc = GPUTextureDescription::New3D(resolution.X, resolution.Y, resolution.Z, format, GPUTextureFlags::ShaderResource | GPUTextureFlags::UnorderedAccess, mipCount);
if (outputSDF)
{
*outputSDF = sdf;
if (!outputSDF->Texture)
outputSDF->Texture = GPUTexture::New();
if (outputSDF->Texture->Init(textureDesc))
{
SAFE_DELETE_GPU_RESOURCE(outputSDF->Texture);
return true;
}
}
// TODO: support GPU to generate model SDF on-the-fly (if called during rendering)
// Setup acceleration structure for fast ray tracing the mesh triangles
MeshAccelerationStructure scene;
if (inputModel)
scene.Add(inputModel, lodIndex);
else if (modelData)
scene.Add(modelData, lodIndex);
scene.BuildBVH();
// Allocate memory for the distant field
const int32 voxelsSize = resolution.X * resolution.Y * resolution.Z * formatStride;
void* voxels = Allocator::Allocate(voxelsSize);
Vector3 xyzToLocalMul = uvwToLocalMul / Vector3(resolution);
Vector3 xyzToLocalAdd = uvwToLocalAdd;
const Vector2 encodeMAD(0.5f / sdf.MaxDistance * formatMaxValue, 0.5f * formatMaxValue);
const Vector2 decodeMAD(2.0f * sdf.MaxDistance / formatMaxValue, -sdf.MaxDistance);
int32 voxelSizeSum = voxelsSize;
// TODO: use optimized sparse storage for SDF data as hierarchical bricks as in papers below:
// https://graphics.pixar.com/library/IrradianceAtlas/paper.pdf
// http://maverick.inria.fr/Membres/Cyril.Crassin/thesis/CCrassinThesis_EN_Web.pdf
// http://ramakarl.com/pdfs/2016_Hoetzlein_GVDB.pdf
// https://www.cse.chalmers.se/~uffe/HighResolutionSparseVoxelDAGs.pdf
// Brute-force for each voxel to calculate distance to the closest triangle with point query and distance sign by raycasting around the voxel
const int32 sampleCount = 12;
Array<Vector3> sampleDirections;
sampleDirections.Resize(sampleCount);
{
RandomStream rand;
sampleDirections.Get()[0] = Vector3::Up;
sampleDirections.Get()[1] = Vector3::Down;
sampleDirections.Get()[2] = Vector3::Left;
sampleDirections.Get()[3] = Vector3::Right;
sampleDirections.Get()[4] = Vector3::Forward;
sampleDirections.Get()[5] = Vector3::Backward;
for (int32 i = 6; i < sampleCount; i++)
sampleDirections.Get()[i] = rand.GetUnitVector();
}
Function<void(int32)> sdfJob = [&sdf, &resolution, &sampleDirections, &scene, &voxels, &xyzToLocalMul, &xyzToLocalAdd, &encodeMAD, &formatStride, &formatWrite](int32 z)
{
PROFILE_CPU_NAMED("Model SDF Job");
float hitDistance;
Vector3 hitNormal, hitPoint;
Triangle hitTriangle;
const int32 zAddress = resolution.Y * resolution.X * z;
for (int32 y = 0; y < resolution.Y; y++)
{
const int32 yAddress = resolution.X * y + zAddress;
for (int32 x = 0; x < resolution.X; x++)
{
float minDistance = sdf.MaxDistance;
Vector3 voxelPos = Vector3((float)x, (float)y, (float)z) * xyzToLocalMul + xyzToLocalAdd;
// Point query to find the distance to the closest surface
scene.PointQuery(voxelPos, minDistance, hitPoint, hitTriangle);
// Raycast samples around voxel to count triangle backfaces hit
int32 hitBackCount = 0, hitCount = 0;
for (int32 sample = 0; sample < sampleDirections.Count(); sample++)
{
Ray sampleRay(voxelPos, sampleDirections[sample]);
if (scene.RayCast(sampleRay, hitDistance, hitNormal, hitTriangle))
{
hitCount++;
const bool backHit = Vector3::Dot(sampleRay.Direction, hitTriangle.GetNormal()) > 0;
if (backHit)
hitBackCount++;
}
}
float distance = minDistance;
// TODO: surface thickness threshold? shift reduce distance for all voxels by something like 0.01 to enlarge thin geometry
//if ((float)hitBackCount > )hitCount * 0.3f && hitCount != 0)
if ((float)hitBackCount > (float)sampleDirections.Count() * 0.6f && hitCount != 0)
{
// Voxel is inside the geometry so turn it into negative distance to the surface
distance *= -1;
}
const int32 xAddress = x + yAddress;
formatWrite((byte*)voxels + xAddress * formatStride, distance * encodeMAD.X + encodeMAD.Y);
}
}
};
JobSystem::Execute(sdfJob, resolution.Z);
// Cache SDF data on a CPU
if (outputStream)
{
outputStream->WriteInt32(1); // Version
ModelSDFHeader data(sdf, textureDesc);
outputStream->Write(&data);
ModelSDFMip mipData(0, resolution.X * formatStride, voxelsSize);
outputStream->Write(&mipData);
outputStream->WriteBytes(voxels, voxelsSize);
}
// Upload data to the GPU
if (outputSDF)
{
BytesContainer data;
data.Link((byte*)voxels, voxelsSize);
auto task = outputSDF->Texture->UploadMipMapAsync(data, 0, resolution.X * formatStride, voxelsSize, true);
if (task)
task->Start();
}
// Generate mip maps
void* voxelsMip = nullptr;
for (int32 mipLevel = 1; mipLevel < mipCount; mipLevel++)
{
Int3 resolutionMip = Int3::Max(resolution / 2, Int3::One);
const int32 voxelsMipSize = resolutionMip.X * resolutionMip.Y * resolutionMip.Z * formatStride;
if (voxelsMip == nullptr)
voxelsMip = Allocator::Allocate(voxelsMipSize);
// Downscale mip
Function<void(int32)> mipJob = [&voxelsMip, &voxels, &resolution, &resolutionMip, &encodeMAD, &decodeMAD, &formatStride, &formatRead, &formatWrite](int32 z)
{
PROFILE_CPU_NAMED("Model SDF Mip Job");
const int32 zAddress = resolutionMip.Y * resolutionMip.X * z;
for (int32 y = 0; y < resolutionMip.Y; y++)
{
const int32 yAddress = resolutionMip.X * y + zAddress;
for (int32 x = 0; x < resolutionMip.X; x++)
{
// Linear box filter around the voxel
// TODO: use min distance for nearby texels (texel distance + distance to texel)
float distance = 0;
for (int32 dz = 0; dz < 2; dz++)
{
const int32 dzAddress = (z * 2 + dz) * (resolution.Y * resolution.X);
for (int32 dy = 0; dy < 2; dy++)
{
const int32 dyAddress = (y * 2 + dy) * (resolution.X) + dzAddress;
for (int32 dx = 0; dx < 2; dx++)
{
const int32 dxAddress = (x * 2 + dx) + dyAddress;
const float d = formatRead((byte*)voxels + dxAddress * formatStride) * decodeMAD.X + decodeMAD.Y;
distance += d;
}
}
}
distance *= 1.0f / 8.0f;
const int32 xAddress = x + yAddress;
formatWrite((byte*)voxelsMip + xAddress * formatStride, distance * encodeMAD.X + encodeMAD.Y);
}
}
};
JobSystem::Execute(mipJob, resolutionMip.Z);
// Cache SDF data on a CPU
if (outputStream)
{
ModelSDFMip mipData(mipLevel, resolutionMip.X * formatStride, voxelsMipSize);
outputStream->Write(&mipData);
outputStream->WriteBytes(voxelsMip, voxelsMipSize);
}
// Upload to the GPU
if (outputSDF)
{
BytesContainer data;
data.Link((byte*)voxelsMip, voxelsMipSize);
auto task = outputSDF->Texture->UploadMipMapAsync(data, mipLevel, resolutionMip.X * formatStride, voxelsMipSize, true);
if (task)
task->Start();
}
// Go down
voxelSizeSum += voxelsSize;
Swap(voxelsMip, voxels);
resolution = resolutionMip;
}
Allocator::Free(voxelsMip);
Allocator::Free(voxels);
#if !BUILD_RELEASE
auto endTime = Platform::GetTimeSeconds();
LOG(Info, "Generated SDF {}x{}x{} ({} kB) in {}ms for {}", resolution.X, resolution.Y, resolution.Z, voxelSizeSum / 1024, (int32)((endTime - startTime) * 1000.0), assetName);
#endif
return false;
}
#if USE_EDITOR
void RemoveNamespace(String& name)
{
@@ -1308,3 +1611,5 @@ bool ModelTool::FindTexture(const String& sourcePath, const String& file, String
}
#endif
#endif