Function convertToInstances

source/MRVoxels/MRVolumeSegment.cpp:434–483

}

Expected<std::vector<Mesh>> convertToInstances( const VdbVolume& mask, const std::vector<VdbVolume>& voxelSeeds, size_t minSize, ProgressCallback cb = {} )
{
    MR_TIMER;
    std::vector<VoxelBitSet> seeds;
    VoxelBitSet allSeeds;
    for ( auto& seedObj : voxelSeeds )
    {
        auto s = mask2set( seedObj );
        allSeeds |= s;
        if ( s.count() > minSize )
            seeds.push_back( s );
    }

    auto dilatedMask = mask2set( dilateMask( mask ) );
    allSeeds = allSeeds | dilatedMask.flip();

    auto maybeSimpleMask = vdbVolumeToSimpleVolume( mask );
    if ( !maybeSimpleMask )
        return unexpected( maybeSimpleMask.error() );
    auto& simpleMask = *maybeSimpleMask;

    std::vector<Mesh> res;
    auto t = simpleMask; // temporary volume for segmentation
    std::fill( begin( t.data ), end( t.data ), 0.f );
    for ( size_t i = 0; i < seeds.size(); ++i )
    {
        reportProgress( cb, (float)i / seeds.size() );
        const auto& s = seeds[i];
        if ( s.count() < minSize )
            continue;

        auto maybeSegm = segmentVolumeByGraphCut( simpleMask, 3000.f, s, allSeeds - s );
        if ( !maybeSegm )
            return unexpected( maybeSegm.error() );

        std::fill( begin( t.data ), end( t.data ), 0.f );
        for ( auto j : *maybeSegm )
            t.data[j] = 1.f;

        auto grid = simpleVolumeToDenseGrid( t );
        auto mesh = gridToMesh( std::move( grid ), GridToMeshSettings{
            .voxelSize = t.voxelSize,
            .isoValue = 0.5f,
        } ).value();

        res.push_back( std::move( mesh ) );
    }

    return res;
}

}