Method SetupSplatMap

Source/Engine/Terrain/TerrainPatch.cpp:1037–1182

}

bool TerrainPatch::SetupSplatMap(int32 index, int32 splatMapLength, const Color32* splatMap, bool forceUseVirtualStorage)
{
    PROFILE_CPU_NAMED("Terrain.SetupSplatMap");
    PROFILE_MEM(LevelTerrain);
    CHECK_RETURN(index >= 0 && index < TERRAIN_MAX_SPLATMAPS_COUNT, true);
    if (splatMap == nullptr)
    {
        LOG(Warning, "Cannot create terrain without any splatmap specified.");
        return true;
    }
    TerrainDataUpdateInfo info(this, _yOffset, _yHeight);
    if (splatMapLength != info.HeightmapLength)
    {
        LOG(Warning, "Invalid splatmap length. Terrain of chunk size equal {0} uses heightmap of size {1}x{1} (heightmap array length must be {2}). Input heightmap has length {3}.", info.ChunkSize, info.HeightmapSize, info.HeightmapLength, splatMapLength);
        return true;
    }
    const PixelFormat pixelFormat = PixelFormat::R8G8B8A8_UNorm;

    // Ensure that terrain has a valid heightmap
    if (Heightmap == nullptr)
    {
        if (InitializeHeightMap() || Heightmap == nullptr)
        {
            LOG(Warning, "Cannot modify splatmap without valid heightmap loaded.");
            return true;
        }
    }

    // Input splatmap data overlaps on chunk edges but it needs to be duplicated for chunks
    const int32 pixelStride = PixelFormatExtensions::SizeInBytes(pixelFormat);
    const int32 lodCount = Math::Min<int32>(_terrain->_lodCount, MipLevelsCount(info.VertexCountEdge) - 2);

    // Prepare
#if USE_EDITOR
    const bool useVirtualStorage = Editor::IsPlayMode || forceUseVirtualStorage;
#else
    const bool useVirtualStorage = true;
#endif
#if USE_EDITOR
    String splatMapPath;
    if (!useVirtualStorage)
    {
        if (!_terrain->GetScene())
        {
            LOG(Error, "Cannot create non-virtual terrain. Add terrain actor to scene first (needs scene folder path for target assets location).");
            return true;
        }
        const String cacheDir = _terrain->GetScene()->GetDataFolderPath() / TEXT("Terrain/") / _terrain->GetID().ToString(Guid::FormatType::N);

        // Prepare asset path for the non-virtual assets
        splatMapPath = cacheDir + String::Format(TEXT("_{0:2}_{1:2}_Splatmap{3}.{2}"), _x, _z, ASSET_FILES_EXTENSION, index);
    }
#endif

    // Create heightmap texture data source container
    auto initData = New<TextureBase::InitData>();
    initData->Format = pixelFormat;
    initData->Width = info.TextureSize;