Method CacheHeightData

Source/Engine/Terrain/TerrainPatch.cpp:1253–1322

}

void TerrainPatch::CacheHeightData()
{
    if (Heightmap == nullptr)
    {
        LOG(Error, "Missing heightmap.");
        return;
    }
    PROFILE_CPU_NAMED("Terrain.CacheHeightData");
    PROFILE_MEM(LevelTerrain);
    const TerrainDataUpdateInfo info(this);

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

    // Get the LOD0 mip map data and extract the heightmap
    auto lock = Heightmap->LockData();
    BytesContainer mipLOD0;
    Heightmap->GetMipDataWithLoading(0, mipLOD0);
    if (mipLOD0.IsInvalid())
    {
        LOG(Error, "Failed to get patch heightmap data.");
        return;
    }

    // Allocate data
    _cachedHeightMap.Resize(info.HeightmapLength);
    _cachedHolesMask.Resize(info.HeightmapLength);
    _wasHeightModified = false;

    // Extract heightmap data and denormalize it to get the pure height field
    const float patchOffset = _yOffset;
    const float patchHeight = _yHeight;
    const auto heightmapPtr = _cachedHeightMap.Get();
    const auto holesMaskPtr = _cachedHolesMask.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;
                const int32 sx = chunkHeightmapX + x;
                const int32 textureIndex = tz + tx;
                const int32 heightmapIndex = sz + sx;