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🚗 How to Create a Scenario File

This guide walks you through the steps to create a custom scenario file for simulation or testing purposes.

📝 Steps

1. Copy an Existing Scenario

Start by copying any working scenario file. This ensures you have a valid structure and format to begin with. 

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cp existing_scenario.py my_custom_scenario.py

2. Start the Goal Picking Tool

To use the interactive goal picker tool:

  1. Start lichtblick suite from the ADORe project root: 

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    just lichtblick

  2. Open the goal picker tool in your browser:

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just api_start


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chromium http://localhost:8080/assets/goal_picker.html
or use the direct link: http://localhost:8080/assets/goal_picker.html

  1. Use the tool to:
  2. Search for locations using the search box
  3. Click on the map to place start and goal markers
  4. Toggle between start and goal placement modes
  5. View coordinates in both Lat/Long and UTM formats
  6. Copy the generated Python code directly from the text boxes

3. Get Start and Goal Coordinates

You can obtain coordinates using one of these methods:

Method A: Goal Picker Tool (Recommended) - Use the goal_picker.html tool as described above - This tool provides both coordinate formats and generates Python code automatically - Simply click on the map to place markers and copy the generated code

Method B: Google Maps - Use Google Maps to select your desired start point and goal point - Right-click on the location and choose What's here? - Copy the latitude and longitude for both start and goal points

4. Define Positions Using the New Position Class

You can now define positions using either Lat/Long or UTM coordinates with the new Position class:

Option A: Using Lat/Long coordinates 

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from scenario_helpers.simulated_vehicle import Position

start_position = Position(lat_long=(52.314562, 10.560474), psi=0.0)
goal_position = Position(lat_long=(52.313533, 10.560554))

Option B: Using UTM coordinates 

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from scenario_helpers.simulated_vehicle import Position

start_position = Position(utm=(606372, 5797172, 32, 'N'), psi=0.0)
goal_position = Position(utm=(606380, 5797058, 32, 'N'))

Option C: Legacy tuple format (still supported) 

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start_position = (606529.67, 5797315.01, -3.23)
goal_position = (606447.98, 5797272.22)

> 💡TIP: The Position class automatically converts between coordinate systems, so you can use whichever format is most convenient for your source data.

5. Update Your Scenario File

Open your scenario file and update the position definitions:

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from scenario_helpers.simulated_vehicle import Position

start_position = Position(lat_long=(52.314562, 10.560474), psi=3.04)
goal_position = Position(lat_long=(52.313533, 10.560554))

def generate_launch_description():
    return LaunchDescription([
        *create_simulated_vehicle_nodes(
            namespace="ego_vehicle",
            start_position=start_position,
            goal_position=goal_position,
            map_file=map_file,
            model_file=vehicle_model_file,
            # ... other parameters
        )
    ])

6. Set the Start Heading

The start heading (orientation in radians) can be critical for correct vehicle behavior: - Try an initial value like 0.0 or 1.57 (90°). - Adjust the heading using a trial-and-error method until the vehicle starts in the correct direction. - The heading is specified as the psi parameter in the Position class or as the third element in the legacy tuple format.

✅ Example Entry

New Position class format: 

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from scenario_helpers.simulated_vehicle import Position

start_position = Position(lat_long=(52.314562, 10.560474), psi=3.04)
goal_position = Position(lat_long=(52.313533, 10.560554))

Alternative UTM format: 

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from scenario_helpers.simulated_vehicle import Position

start_position = Position(utm=(606372, 5797172, 32, 'N'), psi=3.04)
goal_position = Position(utm=(606380, 5797058, 32, 'N'))

Legacy tuple format: 

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start_position = (606529.67, 5797315.01, -3.23)
goal_position = (606447.98, 5797272.22)

🔁 Final Check

Before running the scenario: - ✅ Validate the file syntax. - ✅ Make sure start and goal positions make sense visually. - ✅ Run the simulation and fine-tune as needed. - ✅ Test both coordinate formats to ensure compatibility. - ✅ Verify the import statement for the Position class is included.