Environment Configuration

Configuration is split between the environment ID and optional keyword arguments passed to make. The ID chooses the map, number of agents, sensor mode, collision mode, rewards, controls, control-step ratio, and episode length. Keyword arguments override fields on f1tenth_gym_jax.envs.utils.Param.

Environment IDs

The canonical ID format is:

{map}_{num_agents}_{scan|noscan}_{collision|nocollision}_{rewards}_{longitudinal+steering}_{timestep_ratio}_{max_steps}_v0

For the default 90-second episode length, omit max_steps:

{map}_{num_agents}_{scan|noscan}_{collision|nocollision}_{rewards}_{longitudinal+steering}_{timestep_ratio}_v0

Older model filenames that omit timestep_ratio are still accepted for compatibility and use timestep_ratio=1.

Examples:

from f1tenth_gym_jax import make

env = make(
    "Spielberg_2_scan_collision_progress+alive_velocity+steeringangle_10_500_v0"
)

default_length_env = make(
    "Spielberg_1_scan_collision_progress_acceleration+steeringvelocity_10_v0"
)

ID Fields

map

A registered map name such as Spielberg, Monza, or Spa. Use f1tenth_gym_jax.registration.list_available_maps to inspect the current built-in and locally cached maps.

num_agents

Positive integer number of cars in the environment.

scan or noscan

Enables or disables laser scan observations.

collision or nocollision

Enables or disables vehicle and map collision termination.

rewards

+-joined subset of time, progress, and alive.

longitudinal+steering

Longitudinal control is acceleration or velocity. Steering control is steeringvelocity or steeringangle.

timestep_ratio

Number of dynamics integration steps per environment control step.

max_steps

Maximum number of environment control steps before termination. The default shorthand computes int(90 / (timestep * timestep_ratio)).

Actions and Bounds

The environment ID names controls as longitudinal+steering for readability, but action vectors are ordered as [steering_command, longitudinal_command]. For example, an acceleration+steeringvelocity environment expects [steering_velocity, acceleration].

Inspect the exact bounds from the environment:

env = make(
    "Spielberg_1_noscan_nocollision_progress_acceleration+steeringvelocity_1_v0"
)
action_space = env.action_space("agent_0")
print(action_space.low, action_space.high)

Keyword Overrides

Additional keyword arguments passed to make override Param fields.

env = make(
    "Spielberg_1_noscan_nocollision_progress_acceleration+steeringvelocity_1_v0",
    model="ks",
    integrator="euler",
    observe_others=False,
    mu=1.0,
    timestep=0.02,
)

Common overrides:

Field	Values	Effect
model	"st", "st_smooth", "ks"	Selects the single-track or kinematic bicycle dynamics.
integrator	"rk4", "euler"	Selects the micro-step integrator.
timestep	positive float	Dynamics integration step in seconds.
timestep_ratio	positive integer	Integration micro-steps per environment step.
observe_others	boolean	Adds relative state of other agents to each observation.
produce_scans	boolean	Adds range scan beams to each observation.
collision_on	boolean	Enables vehicle-vehicle and vehicle-map collision checks.
max_num_laps	positive integer	Ends an episode after this many completed laps.
max_steps	positive integer	Ends an episode after this many control steps.

Vehicle parameters such as mu, C_Sf, C_Sr, lf, lr, h, m, I, steering limits, acceleration limits, vehicle dimensions, and scan parameters are also configurable through the same keyword override path. See f1tenth_gym_jax.envs.utils.Param for the full set of fields.

Observation Layout

Each agent observation starts with Frenet state [s, ey, epsi] followed by the configured Cartesian dynamics state. If observe_others=True, relative states for the other agents are appended as [relative_x, relative_y, longitudinal_v, relative_psi] per other agent. If scans are enabled, scan beams are appended after the state fields.

The index groups are exposed as env.observation_space_ind.

Maps and Cache

Bundled maps are loaded from the installed package. Downloaded maps are stored under $XDG_CACHE_HOME/f1tenth_gym_jax/maps by default. Set F1TENTH_GYM_JAX_MAP_DIR to use a different writable map cache.