I think that .sog and .spz fill different needs. .SOG is a partitioned format with LOD support, thus it is designed for massive gs3d scenes. SPZ is has neithe

I think that .sog and .spz fill different needs. .SOG is a partitioned format with LOD support, thus it is designed for massive gs3d scenes. SPZ is has neither of those features, and thus is simpler. Given that ThreeJS itself doesn't yet support partitioning and LOD for its gs3d data - although it will come eventually - I figured that SPZ was a good fit for its initial capabilities. SPZ also has wider support right now compared to SOG.