This example demonstrates how to bypass the Hyperloop limitations when using external generators by switching the configuration to hybrid mode, using the new GeneratorHybrid.switchExtToHybrid parameter (set to false by default).

This solution works only with updated O2sim versions containing the switchExtToHybrid option.

Two example configuration files are provided, each pointing to different hybrid JSON files:

• GeneratorHyperloopHybridCocktail.ini → Creates a cocktail mixing two Pythia8 based generators and a boxgen instance
• GeneratorHyperloopHybrid.ini → Defines sequential generation of boxgen and EPOS4 events called with an external generator

This script demonstrates event generation using the DPL framework, launching it with the external generator in hybrid mode.

• -i, --ini CONFIG → Specifies the configuration ini file (default: GeneratorHyperloopHybridCocktail.ini)
• -n, --nevents EVENTS → Sets the number of events to generate (default: 5)
• -h, --help → Prints usage instructions and o2-sim-dpl-eventgen help
• -- → Passes remaining command line arguments to o2-sim-dpl-eventgen

Run with default settings (5 events using cocktail configuration):

./rundpl.sh

Generate 10 events using the sequential configuration:

./rundpl.sh -n 10 -i ${O2_ROOT}/examples/ExternalToHybrid/GeneratorHyperloopHybrid.ini

• O2sim version with switchExtToHybrid support
• O2_ROOT and O2DPG_MC_CONFIG_ROOT environment variable must be loaded (possibly via O2sim directly)
• Appropriate external generator configurations (e.g., EPOS4) must be available