Creating Camera Curves

This tutorial walks you through creating custom camera effects using Motion's curve system. You'll learn to create head bob, landing impact, and other procedural camera animations.

Overview

Motion's camera system uses UCurveVector assets to define procedural animations. Each curve has X, Y, Z channels that can represent either location or rotation offsets applied to the camera over time.

Prerequisites

• MotionCameraComponent added to your character
• MotionCameraEventBus component for receiving events
• Basic familiarity with Unreal's Curve Editor

Step 1: Create a Curve Asset

1. In Content Browser, right-click and select Miscellaneous > Curve
2. Choose CurveVector as the curve type
3. Name it descriptively (e.g., Curve_HeadBob or Curve_LandingImpact)

Step 2: Design Your Curve

Open the curve asset in the Curve Editor. You have three channels:

Channel	Location	Rotation
X (Red)	Right/Left	Roll (tilt)
Y (Green)	Forward/Back	Pitch (nod)
Z (Blue)	Up/Down	Yaw (turn)

TIP

Each curve channel affects both location and rotation simultaneously. For location-only effects, keep values small (0.1-1.0). For rotation-only effects, design curves that return to zero position to minimize visual location offset.

Example: Head Bob Curve

A subtle walking head bob:

Time    X        Y        Z
0.0     0        0        0
0.25    0.5      0        1.0
0.5     0        0        0
0.75   -0.5      0        1.0
1.0     0        0        0

This creates a figure-8 motion: slight horizontal sway with vertical bounce.

Example: Landing Impact Curve

A sharp downward impact that recovers:

Time    X        Y        Z
0.0     0        0        0
0.05    0        0       -5.0    (sharp drop)
0.15    0        0       -3.0    (partial recovery)
0.4     0        0        0      (full recovery)

Curve Editor Tips

• Right-click on timeline to add keyframes
• Shift+click to add keyframe at current time
• Use Auto tangents for smooth interpolation
• Use Linear tangents for sharp, mechanical motion
• Ctrl+drag to scale sections

Step 3: Configure the Motion Curve Structure

In your component or Blueprint, create an FMotionCurve:

Blueprint Configuration

1. Create a variable of type Struct Motion Curve
2. Configure these properties:

Property	Description	Example Value
Identifier	Unique FName identifier for this curve	"WalkHeadBob"
CurveAsset	Reference to your UCurveVector	Curve_HeadBob
bShouldLoop	Repeat when reaching end	true for head bob
bShouldReverse	Play backwards after forward	true for smooth loops
Tickrate	Playback speed multiplier	1.0 (normal speed)
Multiplier	Scale the effect intensity	0.5 (subtle), 2.0 (intense)
FalloutSmoothness	Blend out duration when removed	0.0 default; use 0.2 for quick fade
bPauseAtNextZero	Pause curve at next zero crossing	true (safer transitions)
ZeroTolerance	Threshold for zero detection	0.01
bRemoveOnComplete	Auto-remove when curve completes	false (manually remove)

C++ Configuration

FMotionCurve HeadBobCurve;
HeadBobCurve.Identifier = TEXT("WalkHeadBob");
HeadBobCurve.CurveAsset = LoadObject<UCurveVector>(nullptr, TEXT("/Game/Curves/CV_HeadBob"));
HeadBobCurve.bShouldLoop = true;
HeadBobCurve.bShouldReverse = true;
HeadBobCurve.Tickrate = 1.0f;
HeadBobCurve.Multiplier = 1.0f;
HeadBobCurve.FalloutSmoothness = 0.2f;

Step 4: Apply the Curve

Method 1: Direct Camera Component Access

// Add the curve
int32 Index = CameraComponent->AddMotionCurve(HeadBobCurve);

// Remove when done
CameraComponent->RemoveMotionCurve(TEXT("WalkHeadBob"));

Method 2: Event Bus (Recommended)

Motion components use the Event Bus to broadcast camera effects:

// From any Motion component
BroadcastCameraEffect(HeadBobCurve, EMotionCameraAction::Add);

// To remove
BroadcastCameraEffect(HeadBobCurve, EMotionCameraAction::Remove);

Method 3: Blueprint Event Bus

1. Get reference to MotionCameraEventBus component
2. Call Broadcast Curve Event with your curve and action (Add/Remove/Pause/Resume)

Step 5: Test and Iterate

1. Play in Editor
2. Enable debug with bShowDebugInformation = true on the camera component
3. Watch the curve effect in action
4. Adjust curve keyframes and multiplier as needed

Debug Commands

# See camera state
log LogMotionCamera Verbose

# View active curves
# Check camera component's GetActiveMotionCurves()

Common Curve Patterns

Walking Head Bob

• Loop: Yes
• Reverse: Yes
• Tickrate: Match walking animation cycle
• Multiplier: 0.3-0.5 (subtle)

Sprint Camera Shake

• Loop: Yes
• Reverse: Yes
• Tickrate: Faster than walk (1.5-2.0)
• Multiplier: 0.5-1.0 (more intense)

Landing Impact

• Loop: No
• Reverse: No
• Tickrate: 1.0
• Multiplier: Scale with fall distance

Jump Takeoff

• Loop: No
• Reverse: No
• Tickrate: 1.0
• Multiplier: 0.5-1.0

Weapon Recoil

• Loop: No
• Reverse: No
• Tickrate: Fast (2.0-3.0)
• Multiplier: Scale with weapon type

Curve Combinations

Multiple curves can be active simultaneously. Motion combines them additively:

// Add walking head bob
CameraComponent->AddMotionCurve(WalkHeadBob);

// Add breathing effect on top
CameraComponent->AddMotionCurve(BreathingCurve);

// Both effects combine

Pause and Resume

Control curves dynamically:

// Pause during cutscene
CameraComponent->SetMotionCurvePaused(TEXT("WalkHeadBob"), true);

// Resume after
CameraComponent->SetMotionCurvePaused(TEXT("WalkHeadBob"), false);

// Reset to start
CameraComponent->ResetMotionCurve(TEXT("WalkHeadBob"));

Static Offsets

For permanent camera adjustments (not time-based):

// Add a lean offset
CameraComponent->AddStaticLocationOffset(TEXT("Lean"), FVector(0, 10, 0));
CameraComponent->AddStaticRotationOffset(TEXT("Lean"), FRotator(0, 0, 5));

// Remove when done
CameraComponent->RemoveStaticLocationOffset(TEXT("Lean"));
CameraComponent->RemoveStaticRotationOffset(TEXT("Lean"));

Troubleshooting

Issue	Solution
Curve not playing	Check AreCameraEffectsEnabled() - may be disabled by tag
Effect too subtle	Increase Multiplier value
Jerky animation	Use Auto or User tangents in curve editor
Curve not looping	Set bShouldLoop = true
Effect persists after removal	Increase FalloutSmoothness for smoother fade
Multiple curves conflicting	Use unique Identifier for each curve

See Also

• MotionCameraComponent - Full component reference
• MotionBreathingComponent - Example curve usage
• Architecture - Camera Event Bus pattern