Four-Way Aerial Dash System

Pressing any WASD direction key + LeftShift triggers the aerial dash: the character teleports 5000 units along the camera direction, with a dissolve effect, a radial blur screen effect, and four-directional dodge montages. The Blueprint version lives in the CharacterBlueprint InputEventGraph; the C++ version lives in CharacterBase::DoAirDash.

— System summary

1. Execution Flow: Blueprint vs C++ Comparison

The two versions follow the same logic chain; the C++ version replaces the Blueprint Timeline-driven flow with in-Tick per-frame driving.

[输入] WASD + LeftShift（空中态）
  │
  ├─ [守卫] 闪现中不重复触发（AirDashRemaining > 0）
  ├─ [守卫] 打断当前普攻（IsAttacking → InterruptAttack / ResetAttackM）
  │
  ├─ [方向] W→前 / S→后 / A→左 / D→右
  │    GetDashDirection() → Controller.GetControlRotation().Vector()（含 Pitch，不压平 Z）
  │    GetDashRightVector() → Controller.GetControlRotation() + Yaw+90°
  │
  ├─ [安全落点] CalculateSafeDashLocation(Dir, DashLerpDistance=5000)
  │    胶囊体 Sweep：碰到 StaticMesh/Landscape 墙 → 回退到最近阻挡点
  │    植被放行：IsVegetationHit 判断关键词，树/草不挡
  │
  ├─ [特效 1] SpawnSystemAttached(DashDissolveFX) → 角色根组件
  ├─ [特效 2] ApplyAirDashScreenEffect() → EF_PP_RadialBlur_Dodge 挂相机 WeightedBlendables
  ├─ [特效 3] FlashCamLag_Disable() → SpringArm CameraLagSpeed = 9999
  ├─ [特效 4] WriteRadialBlurMPC(0.8f) → MPC_RadialBlur BlurIntensity 峰值
  ├─ [溶解] StartDissolveOut() → 角色溶解消失
  │
  ├─ [位移] VLerp(DashLerpStart, DashLerpTarget, α)  0.3s 插值
  │    α = curTime / DashLerpDuration(0.3)
  │    SetActorLocation(Sweep=true)
  │
  └─ [动画] PlayMontage(PickDashMontageByInput(), 1.0f)
          角色_Dodge_Montage / Dodge_Back / Dodge_Left / Dodge_Right

2. Clip-Through Fixes: 5 Iterations from V1 to V5

Clip-through on dash is a critical issue for this feature, fixed over 5 revisions. The root causes are concentrated in CalculateSafeDashLocation: collision channel selection, Sweep result ordering, and Z-axis handling.

Key fix: C++ CalculateSafeDashLocation function body (V5 final)

// TransformCharacter.cpp · CalculateSafeDashLocation
FVector TransformBase::CalculateSafeDashLocation(const FVector& Dir, float MaxDist)
{
    FVector Start = GetActorLocation();
    FVector End = Start + Dir.GetSafeNormal() * MaxDist;

    // 路径 Sweep（胶囊体）
    FHitResult Hit;
    FCollisionQueryParams Params(SCENE_QUERY_STAT(DashSafe), false, this);
    Params.AddIgnoredActor(this);
    GetWorld()->SweepSingleByChannel(Hit, Start, End, FQuat::Identity,
        ECC_WorldStatic, FCollisionShape::MakeCapsule(CapsuleRadius, CapsuleHalfHeight), Params);

    FVector SafeTarget = Hit.bBlockingHit ? Hit.Location : End;

    // Z 轴单独钳位到地面（Landscape + WorldStatic）
    FHitResult GroundHit;
    GetWorld()->LineTraceSingleByChannel(GroundHit,
        SafeTarget + FVector(0, 0, 100), SafeTarget + FVector(0, 0, -500),
        ECC_WorldStatic, Params);

    if (GroundHit.bBlockingHit) {
        // 只改 Z，XY 保持原方向（修复"闪现方向与镜头不对齐"）
        SafeTarget.Z = GroundHit.Location.Z + CapsuleHalfHeight;
    }
    return SafeTarget;
}

Key fix: Blueprint-side bSweep set to false

Blueprint CF51 (SetActorLocation node) → bSweep = false, so Blueprint movement also clips trees (trees are blocked only at the C++ Sweep layer for walls, not for vegetation).

3. VFX List (Down to Asset Path + Attachment Point)

4. Key Variable Quick Reference

5. Issues and Fixes Quick Reference