API Reference

Auto-generated from C++ header files in Source/URLab/Public/. All UPROPERTY specifiers, Blueprint access, and override flags are preserved.

Organised to match the source folder structure in Mujoco/.

Core

Main runtime actors: the physics manager, articulation, and robot.

Name	Kind	Description
EControlSource	Enum
EMjDebugShaderMode	Enum	Per-body visual overlay mode applied during PIE.
EStepMode	Enum	Controls how the physics engine advances the simulation.
FMjEntityRecord	Struct	Cached non-articulation entity metadata: a UMjBody whose owner is
FMjRenderSnapshot	Struct	Single-frame snapshot of MuJoCo state for game-thread consumers.
FMuJoCoDebugData	Struct	Thread-safe buffer for debug visualization data.
FMuJoCoJointState	Struct	Complete runtime state of a 1-DOF joint.
FMuJoCoSpatialVelocity	Struct	Represents 6D spatial velocity (Linear + Angular).
AAMjManager	Class	Thin coordinator actor for the MuJoCo simulation within Unreal Engine.
AMjArticulation	Class	Represents a MuJoCo articulation (robot or multibody system).
UMjDebugVisualizer	Class	Handles debug visualization for the MuJoCo simulation (contact forces, collision wireframes, etc.).
UMjPhysicsEngine	Class	Core physics engine component that owns the MuJoCo simulation lifecycle.
UMjSimulationState	Class	Container for a complete MuJoCo simulation state snapshot.

Core — Spec

Internal spec wrapper types used during compilation.

Name	Kind	Description
FMujocoSpecWrapper	Class	Helper class to simplify building a MuJoCo mjSpec structure from Unreal Engine components.
IMjSpecElement	Class	Interface for components that can register themselves to a MuJoCo spec.

Components — Bodies

MuJoCo rigid body components (e.g., UMjBody).

Name	Kind	Description
EMjBodySleepPolicy	Enum	Per-body sleep policy, matching MuJoCo's mjtSleepPolicy.
UMjBody	Class
UMjFrame	Class	Represents a MuJoCo (mjsFrame).
UMjWorldBody	Class	Represents the node in MuJoCo, functioning as the root scene component

Components — Actuators

Actuator types: Position, Velocity, Motor, Damper, Cylinder, Muscle, Adhesion.

Name	Kind	Description
EMjActuatorType	Enum	Defines the type of actuator dynamics for MuJoCo.
EMjDcMotorInput	Enum	Control input mode for the DC motor actuator. Matches the MuJoCo
UMjActuator	Class	Component representing a MuJoCo actuator.
UMjAdhesionActuator	Class	Specific Adhesion Actuator component.
UMjCylinderActuator	Class	Specific Cylinder Actuator component.
UMjDamperActuator	Class	Specific Damper Actuator component.
UMjDcMotorActuator	Class	Models a DC motor with optional electrical dynamics (inductance),
UMjGeneralActuator	Class	Represents a 'general' actuator in MuJoCo.
UMjIntVelocityActuator	Class	Specific IntVelocity Actuator component.
UMjMotorActuator	Class	Specific Motor Actuator component.
UMjMuscleActuator	Class	Specific Muscle Actuator component.
UMjPositionActuator	Class	Specific Position Actuator component.
UMjVelocityActuator	Class	Specific Velocity Actuator component.

Components — Joints

Joint subtypes: Hinge, Slide, Ball, Free.

Name	Kind	Description
EMjJointType	Enum	Defines the kinematic constraints of a MuJoCo joint.
UMjJoint	Class	Component representing a MuJoCo joint.
UMjBallJoint	Class	Autogenerated component representing the MuJoCo 'ball' element.
UMjFreeJoint	Class	Specific Free Joint component.
UMjHingeJoint	Class	Autogenerated component representing the MuJoCo 'hinge' element.
UMjSlideJoint	Class	Autogenerated component representing the MuJoCo 'slide' element.

Components — Sensors

Sensor types: joint, actuator, touch, rangefinder, tendon, energy, etc.

Name	Kind	Description
EMjCameraMode	Enum	What a UMjCamera captures. Read at SetStreamingEnabled(true) time —
EMjSensorType	Enum	Defines the type of sensor.
FCameraShmWriter	Class	Per-camera SHM publisher.
FCameraZmqWorker	Class	Background thread for publishing high-bandwidth camera frames via ZeroMQ.
UMjCamera	Class	Represents a MuJoCo element as an Unreal sensor component.
UMjSensor	Class	Component representing a sensor in the MuJoCo model.
UMjAccelerometer	Class	Autogenerated component representing the MuJoCo 'accelerometer' element.
UMjActuatorFrcSensor	Class	Autogenerated component representing the MuJoCo 'actuatorfrc' element.
UMjActuatorPosSensor	Class	Autogenerated component representing the MuJoCo 'actuatorpos' element.
UMjActuatorVelSensor	Class	Autogenerated component representing the MuJoCo 'actuatorvel' element.
UMjBallAngVelSensor	Class	Autogenerated component representing the MuJoCo 'ballangvel' element.
UMjBallQuatSensor	Class	Autogenerated component representing the MuJoCo 'ballquat' element.
UMjCamProjectionSensor	Class	Autogenerated component representing the MuJoCo 'camprojection' element.
UMjClockSensor	Class	Autogenerated component representing the MuJoCo 'clock' element.
UMjContactSensor	Class	Autogenerated component representing the MuJoCo 'contact' element.
UMjEKineticSensor	Class	Autogenerated component representing the MuJoCo 'e_kinetic' element.
UMjEPotentialSensor	Class	Autogenerated component representing the MuJoCo 'e_potential' element.
UMjForceSensor	Class	Autogenerated component representing the MuJoCo 'force' element.
UMjFrameAngAccSensor	Class	Autogenerated component representing the MuJoCo 'frameangacc' element.
UMjFrameAngVelSensor	Class	Autogenerated component representing the MuJoCo 'frameangvel' element.
UMjFrameLinAccSensor	Class	Autogenerated component representing the MuJoCo 'framelinacc' element.
UMjFrameLinVelSensor	Class	Autogenerated component representing the MuJoCo 'framelinvel' element.
UMjFramePosSensor	Class	Autogenerated component representing the MuJoCo 'framepos' element.
UMjFrameQuatSensor	Class	Autogenerated component representing the MuJoCo 'framequat' element.
UMjFrameXAxisSensor	Class	Autogenerated component representing the MuJoCo 'framexaxis' element.
UMjFrameYAxisSensor	Class	Autogenerated component representing the MuJoCo 'frameyaxis' element.
UMjFrameZAxisSensor	Class	Autogenerated component representing the MuJoCo 'framezaxis' element.
UMjGeomDistSensor	Class	Autogenerated component representing the MuJoCo 'distance' element.
UMjGeomFromToSensor	Class	Autogenerated component representing the MuJoCo 'fromto' element.
UMjGeomNormalSensor	Class	Autogenerated component representing the MuJoCo 'normal' element.
UMjGyro	Class	Autogenerated component representing the MuJoCo 'gyro' element.
UMjInsideSiteSensor	Class	Autogenerated component representing the MuJoCo 'insidesite' element.
UMjJointActFrcSensor	Class	Autogenerated component representing the MuJoCo 'jointactuatorfrc' element.
UMjJointLimitFrcSensor	Class	Autogenerated component representing the MuJoCo 'jointlimitfrc' element.
UMjJointLimitPosSensor	Class	Autogenerated component representing the MuJoCo 'jointlimitpos' element.
UMjJointLimitVelSensor	Class	Autogenerated component representing the MuJoCo 'jointlimitvel' element.
UMjJointPosSensor	Class	Specific JointPos Sensor component.
UMjJointVelSensor	Class	Autogenerated component representing the MuJoCo 'jointvel' element.
UMjMagnetometer	Class	Autogenerated component representing the MuJoCo 'magnetometer' element.
UMjPluginSensor	Class	Autogenerated component representing the MuJoCo 'plugin' element.
UMjRangeFinderSensor	Class	Autogenerated component representing the MuJoCo 'rangefinder' element.
UMjSubtreeAngMomSensor	Class	Autogenerated component representing the MuJoCo 'subtreeangmom' element.
UMjSubtreeComSensor	Class	Autogenerated component representing the MuJoCo 'subtreecom' element.
UMjSubtreeLinVelSensor	Class	Autogenerated component representing the MuJoCo 'subtreelinvel' element.
UMjTactileSensor	Class	Specific Tactile Sensor component.
UMjTendonActFrcSensor	Class	Autogenerated component representing the MuJoCo 'tendonactuatorfrc' element.
UMjTendonLimitFrcSensor	Class	Autogenerated component representing the MuJoCo 'tendonlimitfrc' element.
UMjTendonLimitPosSensor	Class	Autogenerated component representing the MuJoCo 'tendonlimitpos' element.
UMjTendonLimitVelSensor	Class	Autogenerated component representing the MuJoCo 'tendonlimitvel' element.
UMjTendonPosSensor	Class	Autogenerated component representing the MuJoCo 'tendonpos' element.
UMjTendonVelSensor	Class	Autogenerated component representing the MuJoCo 'tendonvel' element.
UMjTorqueSensor	Class	Autogenerated component representing the MuJoCo 'torque' element.
UMjTouchSensor	Class	Autogenerated component representing the MuJoCo 'touch' element.
UMjUserSensor	Class	Autogenerated component representing the MuJoCo 'user' element.
UMjVelocimeter	Class	Autogenerated component representing the MuJoCo 'velocimeter' element.

Components — Geometry

Geometry attached to bodies: geoms, sites, cameras.

Name	Kind	Description
EMjGeomType	Enum	Defines the geometric primitive type for the MuJoCo geom.
EMjSiteType	Enum	Defines the geometric shape of a MuJoCo site. Mirrors the
UMjGeom	Class
UMjSite	Class	Represents a MuJoCo site element within Unreal Engine.
UMjBoxSite	Class
UMjCapsuleSite	Class
UMjCylinderSite	Class
UMjEllipsoidSite	Class
UMjMeshGeom	Class	Mesh geometry component. Thin wrapper around UMjGeom that sets the type to Mesh.
UMjSphereSite	Class

Components — Primitives

Built-in primitive geom shapes: Box, Sphere, Cylinder.

Name	Kind	Description
UMjBox	Class	Box primitive geometry.
UMjCapsule	Class	Capsule primitive geometry.
UMjCylinder	Class	Cylinder primitive geometry.
UMjEllipsoid	Class	Autogenerated component representing the MuJoCo 'ellipsoid' element.
UMjPlane	Class	Autogenerated component representing the MuJoCo 'plane' element.
UMjSdf	Class	Autogenerated component representing the MuJoCo 'sdf' element.
UMjSphere	Class	Sphere primitive geometry.

Components — Physics

Physics configuration: inertial, contact pairs, contact exclusions.

Name	Kind	Description
UMjInertial	Class

Components — Quick Convert

Convert existing UE actors and terrain to MuJoCo physics with one component.

Name	Kind	Description
AMjHeightfieldActor	Class	An actor that samples terrain height within its bounding box and registers
UMjQuickConvertComponent	Class	Component that enables physically simulated MuJoCo behavior for an Actor.

Networking

ZMQ bridge, sensor broadcaster, and control subscriber for external control.

Name	Kind	Description
FMjInputBinding	Struct
UMjInputMapping	Class	Binds Enhanced Input Actions directly to MuJoCo Actuators.

Replay

Record and replay physics simulation frames.

Name	Kind	Description
FMjBodyKinematics	Struct	Stores kinematics (Position/Velocity) for a single joint or body (if free joint).
FMjReplayFrame	Struct	A snapshot of the entire simulation physics state at a specific time.
FReplayArticulationBinding	Struct	Per-articulation replay settings (enabled, relative position).
FReplaySession	Struct	A named collection of replay frames with source metadata.
AMjReplayManager	Class

UI

Unreal UMG widgets for runtime simulation control.

Name	Kind	Description
EMjPropertyType	Enum	Defines the type of control displayed by the property row.
UMjCameraFeedEntry	Class	UMG widget row that binds to a single UMjCamera and displays its live feed.
UMjPropertyRow	Class	A reusable widget base for a single property row (Label + Control + ValueDisplay).
UMjSimulateWidget	Class	Main dashboard mimicking MuJoCo's "simulate" UI.

Utilities

Helper utilities, logging, mesh tools, and fake-robot debugging actors.

Name	Kind	Description
ActuatorView	Struct	Lightweight wrapper around MuJoCo actuator data.
BodyView	Struct	Lightweight wrapper around MuJoCo body data.
FMjCompilerSettings	Struct	Compiler settings parsed from the element of an MJCF file.
GeomView	Struct	Lightweight wrapper around MuJoCo geom data (model and data).
JointView	Struct	Lightweight wrapper around MuJoCo joint data.
MjOrientationUtils	Class	If true, angles (euler, axisangle, joint range) are in degrees.
MjUtils	Class	Static utility class for common MuJoCo <-> Unreal Engine conversions and helper functions.
MjXmlUtils	Class	Static utility functions for parsing MuJoCo XML nodes.
SensorView	Struct	Lightweight wrapper around MuJoCo sensor data.
SiteView	Struct	Lightweight wrapper around MuJoCo site data.
TendonView	Struct	Lightweight wrapper around MuJoCo tendon data.

Other

Miscellaneous top-level types.

Name	Kind	Description
AURLabGameMode	Class

Bridge

Name	Kind	Description
FOpDecl	Struct	Cross-module registry for RPC handlers. Each handler is registered
FURLabBridgeServerConfig	Struct	Persisted settings for the bridge server. Lives in
FURLabMsgpackUtil	Class	Bidirectional FJsonObject <-> msgpack helpers (Epic's msgpack-cxx in
FURLabRpcDispatcher	Class	Transport-agnostic step-server core.
UURLabBridgeServer	Class	Owns the FURLabRpcDispatcher and every RPC transport.

Cinematics

Name	Kind	Description
FMjCameraWaypoint	Struct	A single camera keyframe: position, rotation, and time.
AMjKeyframeCameraActor	Class	A cinematic camera that lerps through manually placed waypoints.
AMjOrbitCameraActor	Class	A cinematic orbit camera that auto-detects MjArticulations via a box trigger

Components/Constraints

Name	Kind	Description
EMjEqualityType	Enum	Defines the type of equality constraint.
UMjEquality	Class	Component representing a MuJoCo equality constraint.
UMjConnectEquality	Class
UMjFlexEquality	Class
UMjFlexStrainEquality	Class
UMjFlexVertEquality	Class
UMjJointEquality	Class
UMjTendonEquality	Class
UMjWeldEquality	Class

Components/Controllers

Name	Kind	Description
FActuatorBinding	Struct	Maps a MuJoCo actuator to its associated joint DOF addresses.
FMjKeyframePose	Struct	A named pose with joint targets and a hold duration.
UMjArticulationController	Class	Abstract base for custom articulation control laws.
UMjKeyframeController	Class	Cycles through a list of keyframe poses on an MjArticulation.
UMjPDController	Class	Proportional-Derivative controller running at MuJoCo physics rate.
UMjPassthroughController	Class	Writes control values directly to d->ctrl without modification.

Components/Defaults

Name	Kind	Description
UMjDefault	Class	Component that defines a MuJoCo class.

Components/Deformable

Name	Kind	Description
EMjFlexcompType	Enum
UMjFlexcomp	Class	Component representing a MuJoCo flexcomp deformable body.

Components/Forces

Name	Kind	Description
AMjImpulseLauncher	Class	Applies a one-shot MuJoCo force impulse to a target MjBody.

Components/Keyframes

Name	Kind	Description
UMjKeyframe	Class	Component representing a MuJoCo keyframe.

Components/Tendons

Name	Kind	Description
EMjTendonWrapType	Enum	Defines the type of each wrap entry within a tendon.
FMjTendonWrap	Struct	Represents a single wrap entry in a MuJoCo tendon.
UMjTendon	Class	Component representing a MuJoCo tendon.
UMjFixedTendon	Class
UMjSpatialTendon	Class

Generated

Name	Kind	Description
EMjActuatorTrnType	Enum	EMjActuatorTrnType — mirror of MuJoCo's mjtTrn.
EMjBiasType	Enum	EMjBiasType — mirror of MuJoCo's mjtBias.
EMjCameraProjection	Enum	EMjCameraProjection — mirror of MuJoCo's mjtProjection.
EMjCameraTrackingMode	Enum	EMjCameraTrackingMode — mirror of MuJoCo's mjtCamLight.
EMjCone	Enum	EMjCone — mirror of MuJoCo's mjtCone.
EMjDynType	Enum	EMjDynType — mirror of MuJoCo's mjtDyn.
EMjFlexcompDof	Enum	EMjFlexcompDof — URLab editorial enum (no mjt counterpart).
EMjFluidShape	Enum	EMjFluidShape — URLab editorial enum (no mjt counterpart).
EMjGainType	Enum	EMjGainType — mirror of MuJoCo's mjtGain.
EMjGeomInertia	Enum	EMjGeomInertia — URLab editorial enum (no mjt counterpart).
EMjIntegrator	Enum	EMjIntegrator — mirror of MuJoCo's mjtIntegrator.
EMjObjType	Enum	EMjObjType — mirror of MuJoCo's mjtObj.
EMjSolver	Enum	EMjSolver — mirror of MuJoCo's mjtSolver.
FMjOptionGenerated	Struct
FMjStatistic	Struct
FMjVisualGlobal	Struct
FMjVisualHeadlight	Struct
FMjVisualMap	Struct
FMjVisualQuality	Struct
FMjVisualRgba	Struct
FMjVisualScale	Struct
FMjsCompilerOptions	Struct
FMjsSpec	Struct

Input

Name	Kind	Description
UMjInputHandler	Class	Handles keyboard hotkeys for the MuJoCo simulation (debug toggles, pause, reset, etc.).
UMjPerturbation	Class	Mouse-driven body perturbation matching MuJoCo simulate's behaviour.
UMjTwistController	Class	Captures WASD/gamepad input and stores twist commands (vx, vy, yaw_rate)

Transport

Name	Kind	Description
FMjDirectStepCommand	Struct	Heap-allocated wrapper passed by raw pointer through the SPSC queue
FMjPushStateRequest	Struct	One Puppet-mode push-state request. The client owns the integrator;
FMjShmHeader	Struct	Cross-platform shared-memory region for the URLab SHM transport: a
FMjShmRegion	Class	Owning wrapper around a file-backed mmap region.
FMjSnapshotProducer	Class	Build the per-step state snapshot that drives live clients.
FMjStepRequest	Struct	One Direct-mode step request, parsed from a client RPC and pushed to
IMjSnapshotPublisher	Class	Wire-agnostic transport for state-full snapshots.
UMjNetworkManager	Class	Manages camera streaming. (ZMQ broadcaster + subscriber are
UURLabPublishTransport	Class	Abstract base for server -> client streaming transports.
UURLabRpcTransport	Class	Abstract base for request/reply transports owned by the bridge.
UURLabSubscribeTransport	Class	Abstract base for client -> server streaming transports.
UURLabShmRpcTransport	Class	Shared-memory implementation of the bridge's RPC transport.
UURLabZmqRpcTransport	Class	ZMQ REQ/REP adapter. Owned by UURLabBridgeServer; binds a
UURLabZmqSubscribeTransport	Class	ZMQ SUB transport draining inbound control / xfrc messages on