Method PrepareDraw

Source/Engine/Terrain/TerrainChunk.cpp:37–83

}

bool TerrainChunk::PrepareDraw(const RenderContext& renderContext)
{
    // Calculate LOD
    int32 lod;
    const int32 forcedLod = _patch->_terrain->_forcedLod;
    const int32 lodCount = _patch->Heightmap.Get()->StreamingTexture()->TotalMipLevels();
    const int32 minStreamedLod = lodCount - _patch->Heightmap.Get()->GetTexture()->ResidentMipLevels();
    if (forcedLod >= 0)
    {
        lod = forcedLod;
    }
    else
    {
        const int32 lodBias = _patch->_terrain->_lodBias;
        const float lodDistribution = _patch->_terrain->_lodDistribution;
        const float chunkEdgeSize = (_patch->_terrain->_chunkSize * TERRAIN_UNITS_PER_VERTEX);

        // Calculate chunk distance to view
        const auto lodView = (renderContext.LodProxyView ? renderContext.LodProxyView : &renderContext.View);
        const float distance = Float3::Distance(_sphere.Center - lodView->Origin, lodView->Position);
        lod = (int32)Math::Pow(distance / chunkEdgeSize, lodDistribution);
        lod += lodBias;

        //lod = 0;
        //lod = 10;
        //lod = (_x + _z + Terrain::ChunksCountEdge * (_patch->_x + _patch->_z));
        //lod = (int32)Vector2::Distance(Vector2(2, 2), Vector2(_patch->_x, _patch->_z) * Terrain::ChunksCountEdge + Vector2(_x, _z));
        //lod = (int32)(Vector3::Distance(_bounds.GetCenter(), view.Position) / 10000.0f);
    }
    lod = Math::Clamp(lod, minStreamedLod, lodCount - 1);

    // Pick a material
    auto material = OverrideMaterial.Get();
    if (!material || !material->IsLoaded())
    {
        material = _patch->_terrain->Material.Get();
        if (!material || !material->IsLoaded())
            material = TerrainManager::GetDefaultTerrainMaterial();
    }
    if (!material || !material->IsReady() || !material->IsTerrain())
        return false;

    // Cache data
    _cachedDrawLOD = lod;
    _cachedDrawMaterial = material;
    return true;
}

void TerrainChunk::Draw(const RenderContext& renderContext) const
{