Scene Exportation

Overview

The Scene Exportation/ module exports scene geometry and semantic annotations from the CARLA simulator. It consists of two main stages:

1. Asset Exportation (export_scene.py): Exports Actors from the scene to FBX format within the Unreal Engine editor and generates scene metadata JSON files.

2. Scene Reconstruction (actor_recon.py): Converts exported FBX files to OBJ format, performs mesh preprocessing, voxelization, and generates complete scene information.

Running

Step 1: Asset Exportation

1. Open the CARLA Unreal Engine 5 project

2. Load the map to export (e.g., Town01_Opt)

3. Run the Python script in python/cmd console:

path/to/your/script/export_scene.py

Step 2: Scene Reconstruction

Run recon_actor.py to post-process the exported FBX files:

cd scene_exportation
python recon_actor.py

Output Data Format

The exported meshes and reconstructed scenes will be saved as follows:

CarlaOccV1/
└─ SceneMeshes/
   ├── fg_actors/                           # Foreground actors
   │   ├── Car/
   │   │   ├── vehicle_taxi_ford.fbx        # Exported vehicle mesh in FBX format
   │   │   ├── vehicle_taxi_ford.obj        # Converted vehicle mesh in OBJ format
   │   │   └── ...
   │   ├── Truck/
   │   ├── Bus/
   │   └── Pedestrians/
   │       ├── AS_walking04_G3.fbx          # Pedestrian animation sequence in FBX format
   │       ├── frame_info.json              # Animation frame count mapping
   │       └── standard_walking/            # Blender-exported frame-by-frame meshes
   │           ├── frame_xx.fbx
   │           └── frame_xx.obj
   │
   ├── fg_actor_occ/                        # Foreground actor voxelization results in NPZ format
   │   ├── Car/                             # Vehicle occupancy grids
   │   ├── Truck/
   │   ├── Bus/
   │   └── Pedestrians/
   │       └── standard_walking/
   │           └── frame_xx.npz
   │
   │── Town01_Opt/                          # Town-specific background actors
   │   ├── exported_scene_info.json         # Scene metadata from UE5 export
   │   ├── actor_info.json                  # Actor info
   │   ├── Town01_Opt.obj                   # Merged scene mesh (optional)
   │   ├── bg_actors/                       # Background actor OBJ files
   │   │   ├── Building_001.fbx             # Exported background actor mesh in FBX format
   │   │   └── Building_001.obj             # Converted background actor mesh in OBJ format
   │   │   ├── landscape.fbx                # Exported large actors
   │   │   ├── landscape_split_x001_y000.obj # Converted large actors split into chunks
   │   │   └── ...
   │   └── bg_actor_occ/                   # Background actor voxelization results
   │       ├── Building_001.npz
   │       ├── Actor_0_split_x023_y000.npz
   │       └── ...
   │── ...
   └── Town10HD_Opt/