Method CacheSplatData

Source/Engine/Terrain/TerrainPatch.cpp:1324–1391

}

void TerrainPatch::CacheSplatData()
{
    PROFILE_CPU_NAMED("Terrain.CacheSplatData");
    PROFILE_MEM(LevelTerrain);
    const TerrainDataUpdateInfo info(this);

    // Cache all the splatmaps
    for (int32 index = 0; index < TERRAIN_MAX_SPLATMAPS_COUNT; index++)
    {
        // Allocate data
        _cachedSplatMap[index].Resize(info.HeightmapLength);
        _wasSplatmapModified[index] = false;

        // Skip if has missing splatmap asset
        if (Splatmap[index] == nullptr)
        {
            // Initialize splatmap (fill with the first layer if it's the first splatmap)
            const auto fillColor = index == 0 ? Color32(255, 0, 0, 0) : Color32::Transparent;
            _cachedSplatMap[index].SetAll(fillColor);
            continue;
        }

        // Ensure that splatmap data is all loaded
        // TODO: disable streaming for heightmap texture if it's being modified by the editor
        if (Splatmap[index]->WaitForLoaded())
        {
            LOG(Error, "Failed to load patch splatmap data.");
            continue;
        }

        // Get the LOD0 mip map data and extract the splatmap
        auto lock = Splatmap[index]->LockData();
        BytesContainer mipLOD0;
        Splatmap[index]->GetMipDataWithLoading(0, mipLOD0);
        if (mipLOD0.IsInvalid())
        {
            LOG(Error, "Failed to get patch splatmap data.");
            continue;
        }

        // Extract splatmap data
        const auto splatMapPtr = static_cast<Color32*>(_cachedSplatMap[index].Get());
        for (int32 chunkIndex = 0; chunkIndex < Terrain::ChunksCount; chunkIndex++)
        {
            const int32 chunkTextureX = Chunks[chunkIndex]._x * info.VertexCountEdge;
            const int32 chunkTextureZ = Chunks[chunkIndex]._z * info.VertexCountEdge;

            const int32 chunkHeightmapX = Chunks[chunkIndex]._x * info.ChunkSize;
            const int32 chunkHeightmapZ = Chunks[chunkIndex]._z * info.ChunkSize;

            for (int32 z = 0; z < info.VertexCountEdge; z++)
            {
                const int32 tz = (chunkTextureZ + z) * info.TextureSize;
                const int32 sz = (chunkHeightmapZ + z) * info.HeightmapSize;

                for (int32 x = 0; x < info.VertexCountEdge; x++)
                {
                    const int32 tx = chunkTextureX + x;