🌊 Spline Data Generator - Physics-Accurate Breaking Wave Authoring

Advanced spline-based authoring system for creating physically-accurate breaking wave animations with real-time controls and LUA export for Wave Forge Studio integration.

Overview

The Spline Data Generator provides a complete workflow for authoring breaking wave animations using 21 spline curves that represent the full lifecycle of a surf wave—from initial swell through barrel formation to collapse and wash.

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Breaking Wave Spline System

21-Spline Architecture

Each spline represents a phase in the wave lifecycle:

Splines	Phase	Description
01-04	Swell	Deep water wave approaching shore
05-07	Rise	Wave steepening as depth decreases
08-16	Barrel	Wave curling and tube formation
17-21	Collapse & Wash	Breaking and foam rush

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Spline Point Structure

FBreakingWaveSplinePoint

Each control point contains complete transformation data:

USTRUCT(BlueprintType)
struct FBreakingWaveSplinePoint
{
    UPROPERTY(EditAnywhere)
    float InputKey = 0.f;

    UPROPERTY(EditAnywhere)
    FVector Location = FVector::ZeroVector;

    UPROPERTY(EditAnywhere)
    FRotator Rotation = FRotator::ZeroRotator;

    UPROPERTY(EditAnywhere)
    FVector ArriveTangent = FVector::ZeroVector;

    UPROPERTY(EditAnywhere)
    FVector LeaveTangent = FVector::ZeroVector;
};

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Real-Time Controls

Splash Impact

Controls the intensity of the wave breaking curl:

UPROPERTY(EditAnywhere, meta = (ClampMin = "0.0", ClampMax = "1.0"))
float SplashImpact = 1.0f;

Value	Result
0.0	Minimal curl, gentle wave
0.5	Moderate tube formation
1.0	Full barrel, surf wave impact

Surf Wave Height Transition

Controls overall wave crest height:

UPROPERTY(EditAnywhere, meta = (ClampMin = "0.0", ClampMax = "2.0"))
float SurfWaveHeightTransition = 1.0f;

Value	Result
0.0	Minimum wave height
1.0	Default physics-based height
2.0	Double height (exaggerated)

Ripple Wave Height Transition

Controls post-impact ripple amplitude:

UPROPERTY(EditAnywhere, meta = (ClampMin = "0.0", ClampMax = "2.0"))
float RippleWaveHeightTransition = 1.0f;

Physics ratios:

• Pre-breaking (05-07): 20% of crest height
• Post-impact (08-21): 27% of crest height (energy transfer)

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Editor Actions

Spline Generation

// Generate/synchronize splines to match SplineCount
UFUNCTION(CallInEditor)
void GenerateSplines();

// Generate points for all managed splines
UFUNCTION(CallInEditor)
void GeneratePointsForAllSplines();

// Generate points for selected spline only
UFUNCTION(CallInEditor)
void GeneratePointsForSelectedSpline();

Breaking Wave Actions

// Apply physics data with current control values
UFUNCTION(CallInEditor)
void ApplyBreakingWavesData();

// Reset all controls to defaults
UFUNCTION(CallInEditor)
void ResetBreakingWavesDefaults();

// Export modified data to LUA
UFUNCTION(CallInEditor)
void ExportBreakingWavesLUA();

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LUA Import/Export

Wave Forge Studio Integration

Export spline data for use in Wave Forge Studio:

UFUNCTION(CallInEditor)
void ExportLUA();

UFUNCTION(CallInEditor)
void ImportLUA();

Export Format

-- Generated by Oceanology Spline Data Generator
SplineData = {
    Spline_01 = {
        { Key = 0, Location = {0, 0, 0}, Rotation = {0, 0, 0}, 
          ArriveTangent = {100, 0, 0}, LeaveTangent = {100, 0, 0} },
        -- ... more points
    },
    -- ... splines 02-21
}

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Spline Configuration

General Settings

UPROPERTY(EditAnywhere)
FName ActorTag = "OceanologySplineData";

UPROPERTY(EditAnywhere, meta = (ClampMin = "0", ClampMax = "21"))
int32 SplineCount = 0;

UPROPERTY(EditAnywhere, meta = (ClampMin = "2", ClampMax = "20"))
int32 SplinePointCount = 2;

Automatic Management

The system automatically:

• Creates/destroys spline actors based on SplineCount
• Assigns stable names (OceanologySplineData_01 through _21)
• Tags actors for identification
• Positions splines in sequence

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Interpolation System

Smooth Transitions

Splines 08-16 use interpolation between wave states:

void InterpolateSplinePoints(
    const TArray<FBreakingWaveSplinePoint>& PointsA,
    const TArray<FBreakingWaveSplinePoint>& PointsB,
    float Alpha,
    TArray<FBreakingWaveSplinePoint>& OutInterpolatedPoints
) const;

This enables:

• Smooth barrel formation progression
• Continuous wave shape evolution
• Physically plausible transitions

Breakpoint Key

Each spline has a defined breakpoint where the wave impact occurs:

int32 GetBreakpointKeyForSpline(int32 SplineIndex) const;

The breakpoint is Key 4 for most barrel splines (08-16).

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Physics Data

Crest Height Calculation

float GetCrestHeightForSpline(int32 SplineIndex) const;

Key 2 defines the wave crest in all splines.

Ripple Ratio

float GetRippleRatioForSpline(int32 SplineIndex) const;

Returns 0.20 (pre-breaking) or 0.27 (post-impact) based on energy conservation.

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Editor Selection Integration

Interactive Workflow

The generator responds to editor selection:

1. Select a managed spline actor
2. Click "Generate Points for Selected Spline"
3. Points regenerate with current settings

Selection-aware updates via USelection::SelectionChangedEvent.

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Visualization

Spline Colors

Editor visualization uses distinct colors per spline phase:

• Swell: Blue gradient
• Rise: Cyan gradient
• Barrel: Green to yellow
• Collapse: Orange to red

Point Distribution

Points are distributed along local X from 0 to 1000:

void RegenerateSplinePoints(
    USplineComponent* SplineComp, 
    int32 NumPoints
) const;

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Workflow Example

Creating Breaking Waves

1. Place Generator in level
2. Set SplineCount = 21 for full wave lifecycle
3. Generate Splines - Creates all 21 actors
4. Apply Breaking Waves Data - Loads physics-based shapes
5. Adjust Controls - Fine-tune SplashImpact, heights
6. Export LUA - Save for Wave Forge or runtime use

Iterative Refinement

1. Modify control values
2. Apply Breaking Waves Data
3. Preview in editor
4. Repeat until satisfied
5. Export final configuration

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Integration Points

Wave Forge Studio

Exported LUA data can be:

• Imported into Wave Forge Studio
• Modified with Hermite curve tools
• Baked to textures
• Re-imported to Unreal

Runtime Material System

Spline data drives:

• Shore wave displacement
• Foam generation masks
• Normal map generation
• UV animation curves

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Resources

• Discord: #wave-authoring channel
• Wave Forge Studio: Companion web tool
• Documentation: Breaking waves technical guide