3dgs_io

A Python library for reading and writing 3D Gaussian Splatting data in glTF (KHR_gaussian_splatting), 3D Tiles (OGC), SPZ, and PLY formats.

Features

• glTF/GLB save & load with the KHR_gaussian_splatting extension

• SPZ compression via KHR_gaussian_splatting_compression_spz_2

• 3D Tiles reader/writer with multi-layer support (camera 3DGS / LiDAR 2DGS)

• LiDAR 2DGS dedicated I/O for surfel-based Gaussian representations

• SPZ / PLY import & export with automatic coordinate system conversion

• Typed metadata (GlbMetadata) stored in asset.extras

• USDZ scene bundles with a guaranteed metadata.yaml identity card (uuid / scene_id / version_string) at the archive root

• Rigid dynamic-object assets (splatsim.actor_assets/v1): object-local Gaussian clouds for cars and other shape-invariant actors, plus the bindings that say which sequence_tracks track renders with which asset

Installation

Requires Python >= 3.10.

pip install 3dgs-io

Or with uv:

uv add 3dgs-io

API Reference

• gltf_io – glTF/GLB I/O
  • GltfSaveOptions
  • save_gltf()
  • load_gltf()
  • load_gltf_with_metadata()
• spz_io – SPZ / PLY I/O
  • is_ngsp_stream()
  • append_spz_extension()
  • read_spz_extensions()
  • load_spz()
  • save_spz()
  • load_spz_world()
  • save_spz_world()
  • load_spz_world_bytes()
  • save_spz_world_bytes()
  • load_ply()
  • save_ply()
• tiles_io – 3D Tiles Reader
  • BoundingVolumeBox
  • BoundingVolumeRegion
  • BoundingVolumeSphere
  • Tile3DContent
  • load_tileset()
  • merge_tileset()
• tiles_export – 3D Tiles Writer
  • TilesetSaveOptions
  • compute_bounding_volume()
  • save_tileset()
• lidar_2dgs – LiDAR 2DGS I/O
• metadata – Typed Metadata
  • DatasetType
  • TrainingData
  • Checkpoint
  • Export
  • Model
  • Placement
  • GlbMetadata
  • parse_metadata()
  • serialize_metadata()
• usdz_metadata – USDZ Scene-Bundle Manifest
  • Schema
  • Encoding
  • UsdzMetadata
  • default_uuid()
  • encode_usdz_metadata()
  • load_usdz_metadata()
  • make_default_metadata()
• actor_assets – Rigid Dynamic-Object (Actor) Assets
  • Object-local frame
  • Metric scale, not unit scale
  • Assets and tracks are decoupled
  • On-disk layout
  • ACTOR_ASSETS_ARCHIVE_PATH
  • ACTOR_ASSETS_PREFIX
  • FIT_MODES
  • MOTION_MODELS
  • OBJECT_FRAME_CONVENTION
  • SH_POLICIES
  • ActorAsset
  • ActorAssetBank
  • ActorAssetSource
  • ActorInstance
  • build_actor_asset_bank()
  • decode_actor_asset()
  • encode_actor_asset()
  • extract_actor_asset()
  • load_actor_asset_dir()
  • parse_actor_assets()
  • rotate_sh_about_z()
  • save_actor_asset_dir()
  • encode_actor_assets_doc()
  • resolve_actor_asset_bank()
  • serialize_actor_assets()
  • validate_instances_against_tracks()
  • verify_actor_payload()