Principle:ARISE Initiative Robosuite Demonstration Playback
Metadata:
- robosuite
- Imitation_Learning
- Data_Verification
- last_updated: 2026-02-15 12:00 GMT
Overview
Process for verifying collected demonstrations by replaying recorded states or actions in the original simulation environment.
Description
Demonstration playback allows visual verification of collected data quality. Two replay modes exist: (1) State replay - directly sets MuJoCo state from recorded flattened states for exact reproduction, (2) Action replay - re-executes recorded actions in the environment, which may diverge due to numerical precision. The environment is reconstructed from the saved model XML to ensure identical simulation configuration.
Usage
Use after demonstration collection to verify data quality before using for training. Also useful for visualization and debugging.
Theoretical Basis
Demonstration playback operates on two fundamentally different approaches for reproducing collected trajectories:
State Replay: This method provides deterministic reconstruction by directly restoring the complete simulation state at each timestep. The `set_state_from_flattened` function restores the exact MuJoCo simulation state (including positions, velocities, and internal physics state), ensuring perfect reproduction of the recorded trajectory. This is a closed-loop approach where each state is independently restored.
Action Replay: This method re-executes the recorded actions in an open-loop fashion, feeding each action into the environment's step function. Due to numerical precision differences, hardware variations, or non-deterministic elements, this approach may accumulate errors over time, causing the replayed trajectory to diverge from the original. This is useful for testing action sequences but less reliable for exact verification.
Environment Reconstruction: Both replay modes require reconstructing the environment from the saved XML model string. This ensures that the simulation configuration (robot model, objects, scene layout, physics parameters) exactly matches the configuration used during demonstration collection. Without this step, even state replay could fail due to model mismatches.