Method GenerateModelSDF

Source/Engine/Tools/ModelTool/ModelTool.cpp:242–542

};

bool ModelTool::GenerateModelSDF(Model* inputModel, const ModelData* modelData, float resolutionScale, int32 lodIndex, ModelBase::SDFData* outputSDF, MemoryWriteStream* outputStream, const StringView& assetName, float backfacesThreshold, bool useGPU)
{
    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;
    ModelBase::SDFData sdf;
    sdf.WorldUnitsPerVoxel = METERS_TO_UNITS(0.1f) / Math::Max(resolutionScale, 0.0001f); // 1 voxel per 10 centimeters
#if 0
    const float boundsMargin = sdf.WorldUnitsPerVoxel * 0.5f; // Add half-texel margin around the mesh
    bounds.Minimum -= boundsMargin;
    bounds.Maximum += boundsMargin;
#endif
    const Float3 size = bounds.GetSize();
    Int3 resolution(Float3::Ceil(Float3::Clamp(size / sdf.WorldUnitsPerVoxel, 4, 256)));
    Float3 uvwToLocalMul = size;
    Float3 uvwToLocalAdd = bounds.Minimum;
    sdf.LocalToUVWMul = Float3::One / uvwToLocalMul;
    sdf.LocalToUVWAdd = -uvwToLocalAdd / uvwToLocalMul;
    sdf.MaxDistance = size.MaxValue();
    sdf.LocalBoundsMin = bounds.Minimum;
    sdf.LocalBoundsMax = bounds.Maximum;
    sdf.ResolutionScale = resolutionScale;
    sdf.LOD = lodIndex;
    const int32 maxMips = 3;
    const int32 mipCount = Math::Min(MipLevelsCount(resolution.X, resolution.Y, resolution.Z), 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)
        {