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AlpaSim wizard is configured via Hydra and takes in a .yaml configuration file and arbitrary command line overrides. This provides a flexible and powerful way to customize every aspect of the simulation.

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Configuration Files

Example config files are located in src/wizard/configs/. The primary configuration file is base_config.yaml, which has detailed comments on all configuration fields.
Recommended reading: base_config.yaml for comprehensive documentation of all available options.

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Configuration with Hydra

Hydra enables hierarchical configuration composition with command-line overrides. The configuration inheritance order is defined in the defaults section: 
defaults:
  - config_schema      # Python-defined base skeleton
  - _self_             # This file applied on top
  - stable_manifest/oss

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Command Line Overrides

You can override any configuration parameter via command line: 
alpasim_wizard +deploy=local \
  wizard.log_dir=$PWD/tutorial \
  runtime.default_scenario_parameters.n_rollouts=8
Simple value override:
parameter.name=value
Nested parameters:
parent.child.parameter=value
List values:
parameter=[value1,value2,value3]

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Runtime Specification

Under the top-level runtime item in base_config.yaml, we describe the details of the simulation to be performed (as opposed to deployment settings under wizard.* and services.*).

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Key Configuration Fields

The directory where to save .asl logs. It needs to be kept in sync with wizard mount points.
runtime:
  save_dir: /mnt/log_dir
Used to configure simulator scaling properties, including concurrent rollouts per service.
runtime:
  endpoints:
    sensorsim:
      n_concurrent_rollouts: 2
    driver:
      n_concurrent_rollouts: 14
    physics:
      n_concurrent_rollouts: 14
      skip: false
    controller:
      n_concurrent_rollouts: 14
      skip: false
    trafficsim:
      n_concurrent_rollouts: 14
      skip: true  # Not included yet
Concurrency parameters:
  • n_concurrent_rollouts: How many rollouts each service replica can process simultaneously
  • skip: Whether to disable this service
Specify all simulation parameters including timing, cameras, vehicle configuration, and more.
runtime:
  default_scenario_parameters:
    n_sim_steps: 200              # Simulation steps per rollout
    n_rollouts: 1                 # Rollouts per scenario
    force_gt_duration_us: 1_700_000  # 1.7 seconds
    egopose_interval_us: 100_000  # GPS/pose update rate
    control_timestep_us: 100_000  # Inference frequency
    time_start_offset_us: 300_000 # Initial offset

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Scenario Parameters

The default_scenario_parameters section controls the core simulation behavior:

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Timing Configuration

runtime:
  default_scenario_parameters:
    # Simulation duration
    n_sim_steps: 200              # Number of steps to simulate
    n_rollouts: 1                 # Rollouts per scenario
    
    # Timing synchronization (all in microseconds)
    control_timestep_us: 100_000  # 10 Hz inference
    egopose_interval_us: 100_000  # Must match control_timestep_us
    time_start_offset_us: 300_000 # Must be multiple of control_timestep_us
    
    # Ground truth forcing
    force_gt_duration_us: 1_700_000  # 1.7 seconds
Timing Synchronization: egopose_interval_us, control_timestep_us, and camera frame_interval_us must be synchronized. The time_start_offset_us must be a multiple of control_timestep_us.

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Camera Configuration

runtime:
  default_scenario_parameters:
    cameras:
      - height: 320
        width: 512
        logical_id: camera_front_wide_120fov
        frame_interval_us: 100_000    # Must sync with control_timestep_us
        shutter_duration_us: 30_000
        first_frame_offset_us: -30_000
      
      - height: 320
        width: 512
        logical_id: camera_front_tele_30fov
        frame_interval_us: 100_000
        shutter_duration_us: 30_000
        first_frame_offset_us: -30_000
If you change frame_interval_us, consider adjusting driver.inference.Cframes_subsample to maintain consistent behavior.

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Physics and Vehicle

runtime:
  default_scenario_parameters:
    # Physics update mode
    physics_update_mode: "EGO_ONLY"  # or "NONE" for log replay
    
    # Vehicle configuration
    vehicle: null  # Use values from .usdz file
    
    # Ego hood configuration
    ego_mask_rig_config_id: "hyperion_8_1"
    
    # Traffic filtering
    min_traffic_duration_us: 3_000_000  # Ignore actors shorter than 3s

runtime:
  default_scenario_parameters:
    # Route generation type
    route_generator_type: "MAP"  # or "RECORDED"
    
    # Ground truth recording
    send_recording_ground_truth: false

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Evaluation Configuration

The eval section controls metrics computation and video generation:

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Video Configuration

eval:
  video:
    render_video: true
    video_layouts: ["DEFAULT"]  # or ["REASONING_OVERLAY"] or both
    camera_id_to_render: camera_front_wide_120fov
    reasoning_text_refresh_interval_s: 1.0
    overlay_plans_on_camera: true
    render_every_nth_frame: 1
    generate_combined_video: false
    combined_video_speed_factor: 0.33

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Metrics Configuration

eval:
  scorers:
    min_ade:
      time_deltas: [0.5, 1.0, 2.5, 5.0]
      incl_z: false
      target: GT
    
    plan_deviation:
      incl_z: false
      avg_decay_rate: 0.1
      min_timesteps: 5
    
    image:
      camera_logical_id: camera_front_wide_120fov
  
  aggregation_modifiers:
    max_dist_to_gt_trajectory: 4.0

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Map Visualization

eval:
  video:
    map_video:
      map_radius_m: 20
      ego_loc: BOTTOM_CENTER
      rotate_map_to_ego: true
      map_elements_to_plot:
        - ROAD_LANE_CENTER
        - ROAD_LANE_LEFT_EDGE
        - ROAD_LANE_RIGHT_EDGE
        - ROAD_EDGE
        - STOP_LINE
        - GT_LINESTRING
        - EGO_GT_GHOST_POLYGON
        - DRIVER_RESPONSES
        - ROUTE
        - AGENTS

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Service Configuration

The services.* section defines the individual microservice components:
1

Image Selection

Each service specifies its Docker image:
services:
  driver:
    image: ???  # Defined in stable_manifest
2

Volume Mounts

Mount host directories into containers:
services:
  driver:
    volumes:
      - "${defines.drivers}:/mnt/drivers"
      - "${wizard.log_dir}:/mnt/output"
      - "${repo-relative:'src'}:/repo/src"
3

GPU Allocation

Assign GPUs to services:
services:
  driver:
    gpus: [0]
    replicas_per_container: 1

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Wizard Configuration

The wizard.* section defines global properties: 
wizard:
  # Run identification
  run_name: null  # Auto-generated if not set
  
  # Execution method
  run_method: "DOCKER_COMPOSE"  # or "SLURM", "DOCKER"
  
  # Output location (REQUIRED)
  log_dir: ???  # Must be overridden via command line
  
  # Network configuration
  baseport: 6000  # Services use ports 6000, 6001, 6002, ...
  
  # Validation
  validate_mount_points: true
  
  # Services to run
  run_sim_services:
    - driver
    - sensorsim
    - physics
    - trafficsim
    - controller
    - runtime
  
  # Logging
  log_level: INFO  # DEBUG, INFO, WARNING, ERROR

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Viewing Configuration

After running the wizard, you can inspect the resolved configuration:
wizard-config.yaml: Contains the config the wizard used after applying Hydra inheritance. Useful for debugging configuration issues.wizard-config-loadable.yaml: A loadable version of the configuration.generated-user-config-.yaml: Expanded version of the simulation config, possibly split into chunks when simulating on multiple nodes.

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Common Configuration Patterns

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Changing Number of Rollouts

alpasim_wizard +deploy=local \
  wizard.log_dir=$PWD/tutorial \
  runtime.default_scenario_parameters.n_rollouts=8

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Changing Inference Frequency

alpasim_wizard +deploy=local \
  wizard.log_dir=$PWD/tutorial \
  runtime.default_scenario_parameters.control_timestep_us=200000 \
  runtime.default_scenario_parameters.egopose_interval_us=200000 \
  runtime.default_scenario_parameters.time_start_offset_us=600000 \
  runtime.default_scenario_parameters.cameras.0.frame_interval_us=200000

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Disabling Services

alpasim_wizard +deploy=local \
  wizard.log_dir=$PWD/tutorial \
  runtime.endpoints.trafficsim.skip=true
For more configuration examples, see the files in src/wizard/configs/ including driver-specific configs, camera configs, and deployment configs.

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