UMjCamera

Represents a MuJoCo element as an Unreal sensor component.

Placed in the Sensors group because cameras are observation devices, not geometry. The component is cheap by default: no render target or GPU cost is incurred until SetStreamingEnabled(true) is called. Key design points: - No ExportTo / RegisterToSpec — camera is UE-side only, not fed back to MuJoCo. - SetStreamingEnabled() allocates the RT and calls IStreamingManager::AddViewInformation so textures load correctly even when the player pawn is far away. - RequestReadback() enqueues a non-blocking GPU→CPU copy; check IsReadbackReady() on a subsequent tick, then consume with ConsumePixels().

Attribute	Value
Kind	Class
UE Macro	UCLASS
Inherits	UMjComponent
Blueprint Spawnable	✅ Yes

Properties Functions

Properties

Public Properties

Property	Type	Description
Pos	FVector
Quat	FQuat
fovy	float
ipd	float
output	float
target	FString
TrackingMode	EMjCameraTrackingMode
Projection	EMjCameraProjection
CaptureMode	EMjCameraMode	What this camera captures. Read at SetStreamingEnabled(true) time —
DepthNearCm	float	Near clip plane for Depth capture, centimetres. Values below this read as 0.
DepthFarCm	float	Far clip plane for Depth capture, centimetres. Values beyond read as the maximum.
StreamingBoost	float	Boost factor passed to IStreamingManager::AddViewInformation.
CaptureComponent	USceneCaptureComponent2D*	The underlying SceneCaptureComponent2D. Capture is disabled by default.
RenderTarget	UTextureRenderTarget2D*	The render target. Null until SetStreamingEnabled(true) is first called.
bEnableZmqBroadcast	bool	If true, the camera will automatically broadcast its frames over ZeroMQ when streaming is enabled.
ZmqEndpoint	FString	The ZMQ Endpoint for this specific camera (e.g., tcp://0.0.0.0:5558). Must be unique per camera.

Pos

Override-enabled (bOverride_Pos)

• Type: FVector
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: MuJoCo|MjCamera|Spatial Pose

Quat

Override-enabled (bOverride_Quat)

• Type: FQuat
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: MuJoCo|MjCamera|Orientation

fovy

Override-enabled (bOverride_fovy)

• Type: float
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: MuJoCo|MjCamera

ipd

Override-enabled (bOverride_ipd)

• Type: float
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: MuJoCo|MjCamera

output

Override-enabled (bOverride_output)

• Type: float
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: MuJoCo|MjCamera

target

Override-enabled (bOverride_target)

• Type: FString
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: MuJoCo|MjCamera

TrackingMode

Override-enabled (bOverride_TrackingMode)

• Type: EMjCameraTrackingMode
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: MuJoCo|MjCamera

Projection

Override-enabled (bOverride_Projection)

• Type: EMjCameraProjection
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: MuJoCo|MjCamera

CaptureMode

What this camera captures. Read at SetStreamingEnabled(true) time —

• Type: EMjCameraMode
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: MuJoCo|Camera

DepthNearCm

Near clip plane for Depth capture, centimetres. Values below this read as 0.

• Type: float
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: MuJoCo|Camera
• Notes: Override-enabled (CaptureMode)

DepthFarCm

Far clip plane for Depth capture, centimetres. Values beyond read as the maximum.

• Type: float
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: MuJoCo|Camera
• Notes: Override-enabled (CaptureMode)

StreamingBoost

Boost factor passed to IStreamingManager::AddViewInformation.

• Type: float
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: MuJoCo|Camera|Streaming

CaptureComponent

The underlying SceneCaptureComponent2D. Capture is disabled by default.

• Type: USceneCaptureComponent2D*
• Editor: 👁 VisibleAnywhere
• Blueprint: 🟢 ReadOnly
• Category: MuJoCo|Camera

RenderTarget

The render target. Null until SetStreamingEnabled(true) is first called.

• Type: UTextureRenderTarget2D*
• Editor: 👁 VisibleAnywhere
• Blueprint: 🟢 ReadOnly
• Category: MuJoCo|Camera

bEnableZmqBroadcast

If true, the camera will automatically broadcast its frames over ZeroMQ when streaming is enabled.

• Type: bool
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: MuJoCo|Camera|Network

ZmqEndpoint

The ZMQ Endpoint for this specific camera (e.g., tcp://0.0.0.0:5558). Must be unique per camera.

• Type: FString
• Editor: ✏️ EditAnywhere
• Blueprint: 🔵 ReadWrite
• Category: MuJoCo|Camera|Network

Functions

Public Functions

General

Function	Returns	Description
ExportTo()	void	Exports camera properties to a MuJoCo spec camera structure.
ImportFromXml()	void	Imports properties from a MuJoCo XML node.

ExportTo

Exports camera properties to a MuJoCo spec camera structure.

• Signature: ExportTo(mjsCamera* Element, mjsDefault* def)

ImportFromXml

Imports properties from a MuJoCo XML node.

• Signature: ImportFromXml(const class FXmlNode* Node, const struct FMjCompilerSettings& CompilerSettings)

MuJoCo|Camera

Function	Returns	Description
SetStreamingEnabled()	void	Allocates the render target and begins streaming / scene capture.
RequestReadback()	void	Enqueues a non-blocking asynchronous GPU→CPU pixel readback.
IsReadbackReady()	bool	Returns true when the GPU→CPU copy started by RequestReadback() is complete.
ConsumePixels()	TArray<FColor>	Consumes and returns the pixel array from the last completed readback.
GetActualZmqEndpoint()	FString	Returns the ZMQ endpoint actually bound (may differ from ZmqEndpoint if auto-incremented).
GetSelf()	UMjCamera*	Returns the bound camera component pointer (for UI wiring).

SetStreamingEnabled

Allocates the render target and begins streaming / scene capture.

• Signature: SetStreamingEnabled(bool bEnable)
• Blueprint: 🔵 Callable

RequestReadback

Enqueues a non-blocking asynchronous GPU→CPU pixel readback.

• Signature: RequestReadback()
• Blueprint: 🔵 Callable

IsReadbackReady

Returns true when the GPU→CPU copy started by RequestReadback() is complete.

• Signature: IsReadbackReady()
• Blueprint: 🔵 Callable
• Returns: bool

ConsumePixels

Consumes and returns the pixel array from the last completed readback.

• Signature: ConsumePixels()
• Blueprint: 🔵 Callable
• Returns: TArray

GetActualZmqEndpoint

Returns the ZMQ endpoint actually bound (may differ from ZmqEndpoint if auto-incremented).

• Signature: GetActualZmqEndpoint()
• Blueprint: 🔵 Callable
• Returns: FString

GetSelf

Returns the bound camera component pointer (for UI wiring).

• Signature: GetSelf()
• Blueprint: 🔵 Callable
• Returns: UMjCamera*

Private Functions

General

Function	Returns	Description
RefreshHiddenComponentsFromSegPools()	void	For non-seg modes: rebuild HiddenComponents from the currently-live seg pools.

RefreshHiddenComponentsFromSegPools

For non-seg modes: rebuild HiddenComponents from the currently-live seg pools.

• Signature: RefreshHiddenComponentsFromSegPools()