from ai2thor.controller import Controller

controller = Controller(
    agentMode="default",
    visibilityDistance=1.5,
    scene="FloorPlan212",

    # step sizes
    gridSize=0.25,
    snapToGrid=True,
    rotateStepDegrees=90,

    # image modalities
    renderDepthImage=False,
    renderInstanceSegmentation=False,

    # camera properties
    width=300,
    height=300,
    fieldOfView=90
)

Controller Parameters

agentMode

: str = "default"

The type of agent that will interact with the scene. For iTHOR, stick with

agentMode="default"

. RoboTHOR provides the

locobot

as an

agentMode

option, and ManipulaTHOR provides the

arm

as an

agentMode

option.

visibilityDistance

: float = 1.5

Used to set the maximum goal distance in meters between the agent and an object. This affects each object's

visible

property, where, when

True

, then the agent is within

visibilityDistance

of that object and the object appears in the agent's current egocentric frame.

scene

: Optional[str] = None

The name of which scene to initialize. Valid iTHOR scenes are listed here. If unspecified and the

default

agent is being used, an iTHOR scene will be chosen at random.

gridSize

: float = 0.25

The amount, in meters, that the agent moves after calling a move action (e.g.,

MoveAhead

and

MoveBack

snapToGrid

: bool = True

Determines whether the agent’s position is snapped to a grid point after any movement action (e.g.,

MoveAhead

and

TeleportFull

). Grid points are spaced out by

gridSize

. Set to

False

to allow diagonal movement.

rotateStepDegrees

: float = 90

The default amount, in degrees, that the agent rotates after calling a rotate action (i.e.,

RotateLeft

RotateRight

renderDepthImage

: bool = False

When

True

, a depth frame is rendered and made available as an

event.depth_frame

attribute.

Remark

We require this to be explicitly passed in because rendering depth takes longer than rendering RGB alone.

renderInstanceSegmentation

: bool = False

When

True

, a instance segmentation frame is rendered and made available as an

event.instance_segmentation_frame

attribute. Instance segmentation provides segmentation by object instance, where all objects in view are distinguishable.

Remark

We require this to be explicitly passed in because rendering instance segmentation takes longer than rendering RGB alone.

width

: int = 300

The number of horizontal sampled pixels for each frame. This affects every rendered image frame (e.g.,

event.frame

event.depth_frame

event.cv2img

height

: int = 300

The number of vertical sampled pixels for each frame. This affects every rendered image frame (e.g.,

event.frame

event.depth_frame

event.cv2img

fieldOfView

: int = 90

Changes the camera's optical field of view, in degrees. Valid values are in the domain $(0:180)$ . The default field of view when

agentMode="default"

is 90 degrees.

Warning

Not all agent modes have the same default

fieldOfView

. For instance, the

locobot

has a default

fieldOfView

60

degrees.

Reset

Any

Controller

Initialization parameter can later be changed by calling the reset method. For instance, we can call:

controller.reset(scene="FloorPlan319", rotateStepDegrees=30)

The values will default to what they were upon the most recent reset or initialization. For instance, if you initialized with

fieldOfView=45

, then called

reset

with

fieldOfView=60

, calling

reset

again, without passing in

fieldOfView

will keep

fieldOfView=60

Controlling Time

By default, AI2-THOR executes high-level actions that provide a response from the environment after the action completes execution. For instance, if the agent successfully executes an

OpenObject

action, the response is the state of the environment after the action has completely finished executing.

However, we also provide the ability to observe intermediate results, which is discussed in this section.

Pause Physics Auto-Simulation

PausePhysicsAutoSim

toggles off auto-simulation in the environment, which must be called before one can control how much time passes in-between steps.

controller.step("PausePhysicsAutoSim")

Advance Physics Step

AdvancePhysicsStep

responds with an Event after simulating the environment for

timeStep

seconds beyond the current state. Note that

PausePhysicsAutoSim

must be called first, before calling

AdvancePhysicsStep

controller.step(
    action="AdvancePhysicsStep",
    timeStep=0.01
)

Advance Physics Step Parameters

timeStep

: float = 0.01

The amount of time in seconds to advance the physics simulation. Valid values are in $(0:0.05]$ .

Unpause Physics Auto-Simulation

UnpausePhysicsAutoSim

toggles back on the default physics auto-simulation, which returns future events after the action finishes execution.

Warning

Unpausing auto-simulation while objects are still in motion (i.e.,

inMotion=True

on an object's metadata) will freeze each object at its current location. Thus, the remaining motion of such an object will be lost.

To capture the entire movement of an object, do not unpause physics with this action until all objects return

inMotion=False

in their object metadata, which can also be checked with the shorthand of

event.metadata["isSceneAtRest"]

controller.step("UnpausePhysicsAutoSim")

Initialization

Reset

Controlling Time