UMjDebugVisualizer¶

Handles debug visualization for the MuJoCo simulation (contact forces, collision wireframes, etc.).

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

Properties Functions

Properties¶

Public Properties¶

Property	Type	Description
`bShowDebug`	`bool`	If true, draws contact force visualization.
`DebugForceScale`	`float`	Scaling factor for contact force visualization.
`DebugMaxForce`	`float`	Maximum force value for clamping visual size.
`DebugContactPointSize`	`float`	Size of the drawn contact point.
`DebugContactArrowThickness`	`float`	Base thickness of the contact force arrow.
`bGlobalDrawDebugCollision`	`bool`	Toggles debug collision drawing globally for all articulations.
`bGlobalDrawDebugJoints`	`bool`	Toggles debug joint axis/range drawing globally for all articulations.
`bGlobalShowGroup3`	`bool`	Toggles debug Group 3 drawing globally for all articulations.
`bGlobalQuickConvertCollision`	`bool`	Toggles debug collision drawing globally for all QuickConvert components.
`DebugShaderMode`	EMjDebugShaderMode	Per-body overlay shader mode (Island / Segmentation / Off). Cycled via key 6.
`bModulateBySleep`	`bool`	When true, sleeping bodies are dimmed + desaturated on top of the active shader mode.
`SleepValueScale`	`float`	Value (brightness) multiplier applied to sleeping bodies. MuJoCo upstream uses 0.6; default 0.35 dims clearly while keeping hue visible.
`SleepSaturationScale`	`float`	Saturation multiplier applied to sleeping bodies. Keep high to preserve hue identity; lower toward 0 to desaturate sleeping bodies to grey.
`bGlobalDrawTendons`	`bool`	Toggles smooth-tube tendon/muscle rendering. Toggled via key 7.
`TendonTubeRadius`	`float`	Tube radius (cm). Muscle activation scales this up to ~2x per-tendon.
`TendonArcSubdivisions`	`int32`	When a tendon wraps around a cylinder/sphere geom, insert this many intermediate points along the wrap arc.
`OverlayParentMaterial`	`UMaterialInterface*`	Parent material for body/tendon overlay MIDs, probed from engine content at BeginPlay.
`OverlayColorParam`	`FName`	Vector parameter name on OverlayParentMaterial that accepts the overlay colour.

bShowDebug¶

If true, draws contact force visualization.

Type: bool
Editor: ✏️ EditAnywhere
Blueprint: 🔵 ReadWrite
Category: MuJoCo|Debug

DebugForceScale¶

Scaling factor for contact force visualization.

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

DebugMaxForce¶

Maximum force value for clamping visual size.

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

DebugContactPointSize¶

Size of the drawn contact point.

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

DebugContactArrowThickness¶

Base thickness of the contact force arrow.

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

bGlobalDrawDebugCollision¶

Toggles debug collision drawing globally for all articulations.

Type: bool
Editor: ✏️ EditAnywhere
Blueprint: 🔵 ReadWrite
Category: MuJoCo|Debug

bGlobalDrawDebugJoints¶

Toggles debug joint axis/range drawing globally for all articulations.

Type: bool
Editor: ✏️ EditAnywhere
Blueprint: 🔵 ReadWrite
Category: MuJoCo|Debug

bGlobalShowGroup3¶

Toggles debug Group 3 drawing globally for all articulations.

Type: bool
Editor: ✏️ EditAnywhere
Blueprint: 🔵 ReadWrite
Category: MuJoCo|Debug

bGlobalQuickConvertCollision¶

Toggles debug collision drawing globally for all QuickConvert components.

Type: bool
Editor: ✏️ EditAnywhere
Blueprint: 🔵 ReadWrite
Category: MuJoCo|Debug

DebugShaderMode¶

Per-body overlay shader mode (Island / Segmentation / Off). Cycled via key 6.

Type: EMjDebugShaderMode
Editor: ✏️ EditAnywhere
Blueprint: 🔵 ReadWrite
Category: MuJoCo|Debug

bModulateBySleep¶

When true, sleeping bodies are dimmed + desaturated on top of the active shader mode.

Type: bool
Editor: ✏️ EditAnywhere
Blueprint: 🔵 ReadWrite
Category: MuJoCo|Debug

SleepValueScale¶

Value (brightness) multiplier applied to sleeping bodies. MuJoCo upstream uses 0.6; default 0.35 dims clearly while keeping hue visible.

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

SleepSaturationScale¶

Saturation multiplier applied to sleeping bodies. Keep high to preserve hue identity; lower toward 0 to desaturate sleeping bodies to grey.

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

bGlobalDrawTendons¶

Toggles smooth-tube tendon/muscle rendering. Toggled via key 7.

Type: bool
Editor: ✏️ EditAnywhere
Blueprint: 🔵 ReadWrite
Category: MuJoCo|Debug

TendonTubeRadius¶

Tube radius (cm). Muscle activation scales this up to ~2x per-tendon.

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

TendonArcSubdivisions¶

When a tendon wraps around a cylinder/sphere geom, insert this many intermediate points along the wrap arc.

Type: int32
Editor: ✏️ EditAnywhere
Blueprint: 🔵 ReadWrite
Category: MuJoCo|Debug

OverlayParentMaterial¶

Parent material for body/tendon overlay MIDs, probed from engine content at BeginPlay.

Type: UMaterialInterface*

OverlayColorParam¶

Vector parameter name on OverlayParentMaterial that accepts the overlay colour.

Type: FName

Private Properties¶

Property	Type	Description
`InstanceSegSiblings`	`TArray<TObjectPtr<UStaticMeshComponent>>`	Sibling-mesh pool for InstanceSegmentation-mode cameras. Empty when no subscribers.
`SemanticSegSiblings`	`TArray<TObjectPtr<UStaticMeshComponent>>`	Sibling-mesh pool for SemanticSegmentation-mode cameras.
`OriginalMaterials`	`TMap<TWeakObjectPtr<class UStaticMeshComponent>, class UMaterialInterface*>`	Original slot-0 material on meshes we've overridden, so we can restore. Keyed by mesh component.
`OriginalSlotMaterials`	`TMap<TWeakObjectPtr<class UStaticMeshComponent>, TMap<int32, class UMaterialInterface*>>`	Original slot-1..N materials for multi-material meshes. Parallel to OriginalMaterials.
`ActiveMIDs`	`TMap<TWeakObjectPtr<class UStaticMeshComponent>, class UMaterialInstanceDynamic*>`	Dynamic material instances we created per mesh, reused across ticks.
`TendonSegmentPool`	`TArray<class USplineMeshComponent*>`	Pool of spline-mesh components used by the tube tendon render style. Grown on demand.
`TendonSegmentMIDs`	`TArray<class UMaterialInstanceDynamic*>`	One MID per pool entry so each tube can colour independently. Grown in lockstep with TendonSegmentPool.
`TendonTubeMesh`	`class UStaticMesh*`	Base cylinder mesh used for every tendon segment. Loaded from /Engine/BasicShapes at BeginPlay.

InstanceSegSiblings¶

Sibling-mesh pool for InstanceSegmentation-mode cameras. Empty when no subscribers.

Type: TArray>

SemanticSegSiblings¶

Sibling-mesh pool for SemanticSegmentation-mode cameras.

Type: TArray>

OriginalMaterials¶

Original slot-0 material on meshes we've overridden, so we can restore. Keyed by mesh component.

Type: TMap, class UMaterialInterface*>

OriginalSlotMaterials¶

Original slot-1..N materials for multi-material meshes. Parallel to OriginalMaterials.

Type: TMap, TMap\>

ActiveMIDs¶

Dynamic material instances we created per mesh, reused across ticks.

Type: TMap, class UMaterialInstanceDynamic*>

TendonSegmentPool¶

Pool of spline-mesh components used by the tube tendon render style. Grown on demand.

Type: TArray

TendonSegmentMIDs¶

One MID per pool entry so each tube can colour independently. Grown in lockstep with TendonSegmentPool.

Type: TArray

TendonTubeMesh¶

Base cylinder mesh used for every tendon segment. Loaded from /Engine/BasicShapes at BeginPlay.

Type: class UStaticMesh*

Functions¶

Public Functions¶

General¶

Function	Returns	Description
`CaptureDebugData()`	void	Captures debug info from m_data to DebugData. Called on Physics Thread.
`UpdateAllGlobalVisibility()`	void	Applies global debug visibility settings to all active articulations.
`ToggleDebugContacts()`	void	Toggle contact force visualization (key: 1).
`ToggleArticulationCollisions()`	void	Toggle collision wireframes on articulations (key: 3).
`ToggleQuickConvertCollisions()`	void	Toggle collision wireframes on Quick Convert objects (key: 5).
`ToggleDebugJoints()`	void	Toggle joint axes on all articulations (key: 4).
`ToggleVisuals()`	void	Toggle visual mesh visibility on all articulations (key: 2).
`CycleDebugShaderMode()`	void	Cycle per-body shader overlay: Off -> Island -> Segmentation -> Off (key: 6).
`ToggleTendons()`	void	Toggle tendon/muscle spline rendering (key: 7).
`InitializeOverlayMaterial()`	void	Loads /Engine/BasicShapes/BasicShapeMaterial and records the first vector param name.
`UpdateBodyOverlays()`	void	Apply per-body overlay MIDs based on DebugShaderMode, or restore originals if Off.
`ClearBodyOverlays()`	void	Restore original materials recorded at overlay apply time, clear caches.
`UpdateTendonTubes()`	void	Rebuild / reuse the spline-mesh tendon segment pool based on the latest snapshot.
`HideTendonTubes()`	void	Hide the tendon tube pool without destroying it.
`ClearTendonTubes()`	void	Destroy the tube pool entirely. Used on EndPlay.
`AcquireSegPool()`	void	Subscribe a camera to the sibling-mesh pool for Mode.
`ReleaseSegPool()`	void	Unsubscribe a camera. When the last subscriber leaves, the pool is destroyed.
`GetSegPoolSiblings()`	void	Snapshot of a currently-live sibling pool. Used for tests and for

CaptureDebugData¶

Captures debug info from m_data to DebugData. Called on Physics Thread.

Signature: CaptureDebugData()

UpdateAllGlobalVisibility¶

Applies global debug visibility settings to all active articulations.

Signature: UpdateAllGlobalVisibility()

ToggleDebugContacts¶

Toggle contact force visualization (key: 1).

Signature: ToggleDebugContacts()

ToggleArticulationCollisions¶

Toggle collision wireframes on articulations (key: 3).

Signature: ToggleArticulationCollisions()

ToggleQuickConvertCollisions¶

Toggle collision wireframes on Quick Convert objects (key: 5).

Signature: ToggleQuickConvertCollisions()

ToggleDebugJoints¶

Toggle joint axes on all articulations (key: 4).

Signature: ToggleDebugJoints()

ToggleVisuals¶

Toggle visual mesh visibility on all articulations (key: 2).

Signature: ToggleVisuals()

CycleDebugShaderMode¶

Cycle per-body shader overlay: Off -> Island -> Segmentation -> Off (key: 6).

Signature: CycleDebugShaderMode()

ToggleTendons¶

Toggle tendon/muscle spline rendering (key: 7).

Signature: ToggleTendons()

InitializeOverlayMaterial¶

Loads /Engine/BasicShapes/BasicShapeMaterial and records the first vector param name.

Signature: InitializeOverlayMaterial()

UpdateBodyOverlays¶

Apply per-body overlay MIDs based on DebugShaderMode, or restore originals if Off.

Signature: UpdateBodyOverlays()

ClearBodyOverlays¶

Restore original materials recorded at overlay apply time, clear caches.

Signature: ClearBodyOverlays()

UpdateTendonTubes¶

Rebuild / reuse the spline-mesh tendon segment pool based on the latest snapshot.

Signature: UpdateTendonTubes()

HideTendonTubes¶

Hide the tendon tube pool without destroying it.

Signature: HideTendonTubes()

ClearTendonTubes¶

Destroy the tube pool entirely. Used on EndPlay.

Signature: ClearTendonTubes()

AcquireSegPool¶

Subscribe a camera to the sibling-mesh pool for Mode.

Signature: AcquireSegPool(EMjCameraMode Mode, UMjCamera* Camera, TArray<UPrimitiveComponent*>& OutSiblings)

ReleaseSegPool¶

Unsubscribe a camera. When the last subscriber leaves, the pool is destroyed.

Signature: ReleaseSegPool(EMjCameraMode Mode, UMjCamera* Camera)

GetSegPoolSiblings¶

Snapshot of a currently-live sibling pool. Used for tests and for

Signature: GetSegPoolSiblings(EMjCameraMode Mode, TArray<UPrimitiveComponent*>& OutSiblings)

Private Functions¶

General¶

Function	Returns	Description
`GetSegPoolArray()`	`TArray<TObjectPtr<UStaticMeshComponent>>*`	Returns a mutable ref to the pool matching Mode, or null for non-seg modes.
`BuildSegPool()`	void	Build the seg pool for Mode by walking the world's articulations + quick-convert.
`DestroySegPool()`	void	Destroy all siblings in Mode's pool and clear it.
`SpawnSegSibling()`	`UStaticMeshComponent*`	Spawn one sibling mesh for a given original. Returns the new component (already registered).

GetSegPoolArray¶

Returns a mutable ref to the pool matching Mode, or null for non-seg modes.

Signature: GetSegPoolArray(EMjCameraMode Mode)
Returns: TArray>*

BuildSegPool¶

Build the seg pool for Mode by walking the world's articulations + quick-convert.

Signature: BuildSegPool(EMjCameraMode Mode)

DestroySegPool¶

Destroy all siblings in Mode's pool and clear it.

Signature: DestroySegPool(EMjCameraMode Mode)

SpawnSegSibling¶

Spawn one sibling mesh for a given original. Returns the new component (already registered).

Signature: SpawnSegSibling(UStaticMeshComponent* Original, int32 BodyId, uint32 GroupHash, EMjCameraMode Mode)
Returns: UStaticMeshComponent*