void UBuoyancyForceComponent::TickComponent(float DeltaTime, enum ELevelTick TickType, FActorComponentTickFunction *ThisTickFunction)
{
Super::TickComponent(DeltaTime, TickType, ThisTickFunction);
// If disabled or we are not attached to a parent component, return.
if (!bIsActive || !GetAttachParent()) return;
if (!OceanManager) return;
UPrimitiveComponent* BasePrimComp = Cast<UPrimitiveComponent>(GetAttachParent());
if (!BasePrimComp) return;
if (!BasePrimComp->IsSimulatingPhysics())
{
if (!SnapToSurfaceIfNoPhysics) return;
UE_LOG(LogTemp, Warning, TEXT("Running in no physics mode.."));
float waveHeight = OceanManager->GetWaveHeightValue(BasePrimComp->GetComponentLocation(), World, true, TwoGerstnerIterations).Z;
BasePrimComp->SetWorldLocation(FVector(BasePrimComp->GetComponentLocation().X, BasePrimComp->GetComponentLocation().Y, waveHeight));
return;
}
//Get gravity
float Gravity = BasePrimComp->GetPhysicsVolume()->GetGravityZ();
//--------------- If Skeletal ---------------
USkeletalMeshComponent* SkeletalComp = Cast<USkeletalMeshComponent>(GetAttachParent());
if (SkeletalComp && ApplyForceToBones)
{
TArray<FName> BoneNames;
SkeletalComp->GetBoneNames(BoneNames);
for (int32 Itr = 0; Itr < BoneNames.Num(); Itr++)
{
FBodyInstance* BI = SkeletalComp->GetBodyInstance(BoneNames[Itr], false);
if (BI && BI->IsValidBodyInstance()
&& BI->bEnableGravity) //Buoyancy doesn't exist without gravity
{
bool isUnderwater = false;
//FVector worldBoneLoc = SkeletalComp->GetBoneLocation(BoneNames[Itr]);
FVector worldBoneLoc = BI->GetCOMPosition(); //Use center of mass of the bone's physics body instead of bone's location
FVector waveHeight = OceanManager->GetWaveHeightValue(worldBoneLoc, World, true, TwoGerstnerIterations);
float BoneDensity = MeshDensity;
float BoneTestRadius = FMath::Abs(TestPointRadius);
float SignedBoneRadius = FMath::Sign(Gravity) * TestPointRadius; //Direction of radius (test radius is actually a Z offset, should probably rename it!). Just in case we need an upside down world.
//Get density & radius from the override array, if available.
for (int pointIndex = 0; pointIndex < BoneOverride.Num(); pointIndex++)
{
FStructBoneOverride Override = BoneOverride[pointIndex];
if (Override.BoneName.IsEqual(BoneNames[Itr]))
{
BoneDensity = Override.Density;
BoneTestRadius = FMath::Abs(Override.TestRadius);
SignedBoneRadius = FMath::Sign(Gravity) * BoneTestRadius;
}
}
//If test point radius is below water surface, add buoyancy force.
if (waveHeight.Z > (worldBoneLoc.Z + SignedBoneRadius))
{
isUnderwater = true;
float DepthMultiplier = (waveHeight.Z - (worldBoneLoc.Z + SignedBoneRadius)) / (BoneTestRadius * 2);
DepthMultiplier = FMath::Clamp(DepthMultiplier, 0.f, 1.f);
float Mass = SkeletalComp->CalculateMass(BoneNames[Itr]); //Mass of this specific bone's physics body
/**
* --------
* Buoyancy force formula: (Volume(Mass / Density) * Fluid Density * -Gravity) / Total Points * Depth Multiplier
* --------
*/
float BuoyancyForceZ = Mass / BoneDensity * FluidDensity * -Gravity * DepthMultiplier;
//Velocity damping.
FVector DampingForce = -BI->GetUnrealWorldVelocity() * VelocityDamper * Mass * DepthMultiplier;
//Experimental xy wave force
if (EnableWaveForces)
{
float waveVelocity = FMath::Clamp(BI->GetUnrealWorldVelocity().Z, -20.f, 150.f) * (1 - DepthMultiplier);
DampingForce += FVector(OceanManager->GlobalWaveDirection.X, OceanManager->GlobalWaveDirection.Y, 0) * Mass * waveVelocity * WaveForceMultiplier;
}
//Add force to this bone
BI->AddForce(FVector(DampingForce.X, DampingForce.Y, DampingForce.Z + BuoyancyForceZ));
//BasePrimComp->AddForceAtLocation(FVector(DampingForce.X, DampingForce.Y, DampingForce.Z + BuoyancyForceZ), worldBoneLoc, BoneNames[Itr]);
}
//Apply fluid damping & clamp velocity
if (isUnderwater)
{
BI->SetLinearVelocity(-BI->GetUnrealWorldVelocity() * (FluidLinearDamping / 10), true);
BI->SetAngularVelocity(-BI->GetUnrealWorldAngularVelocity() * (FluidAngularDamping / 10), true);
//Clamp the velocity to MaxUnderwaterVelocity
if (ClampMaxVelocity && BI->GetUnrealWorldVelocity().Size() > MaxUnderwaterVelocity)
{
FVector Velocity = BI->GetUnrealWorldVelocity().GetSafeNormal() * MaxUnderwaterVelocity;
BI->SetLinearVelocity(Velocity, false);
}
}
if (DrawDebugPoints)
{
FColor DebugColor = FLinearColor(0.8, 0.7, 0.2, 0.8).ToRGBE();
if (isUnderwater) { DebugColor = FLinearColor(0, 0.2, 0.7, 0.8).ToRGBE(); } //Blue color underwater, yellow out of watter
DrawDebugSphere(World, worldBoneLoc, BoneTestRadius, 8, DebugColor);
}
}
}
return;
}
//--------------------------------------------------------
float TotalPoints = TestPoints.Num();
if (TotalPoints < 1) return;
int PointsUnderWater = 0;
for (int pointIndex = 0; pointIndex < TotalPoints; pointIndex++)
{
if (!TestPoints.IsValidIndex(pointIndex)) return; //Array size changed during runtime
bool isUnderwater = false;
FVector testPoint = TestPoints[pointIndex];
FVector worldTestPoint = BasePrimComp->GetComponentTransform().TransformPosition(testPoint);
FVector waveHeight = OceanManager->GetWaveHeightValue(worldTestPoint, World, !EnableWaveForces, TwoGerstnerIterations);
//Direction of radius (test radius is actually a Z offset, should probably rename it!). Just in case we need an upside down world.
float SignedRadius = FMath::Sign(BasePrimComp->GetPhysicsVolume()->GetGravityZ()) * TestPointRadius;
//If test point radius is below water surface, add buoyancy force.
if (waveHeight.Z > (worldTestPoint.Z + SignedRadius)
&& BasePrimComp->IsGravityEnabled()) //Buoyancy doesn't exist without gravity
{
PointsUnderWater++;
isUnderwater = true;
float DepthMultiplier = (waveHeight.Z - (worldTestPoint.Z + SignedRadius)) / (TestPointRadius * 2);
DepthMultiplier = FMath::Clamp(DepthMultiplier, 0.f, 1.f);
//If we have a point density override, use the overridden value instead of MeshDensity
float PointDensity = PointDensityOverride.IsValidIndex(pointIndex) ? PointDensityOverride[pointIndex] : MeshDensity;
/**
* --------
* Buoyancy force formula: (Volume(Mass / Density) * Fluid Density * -Gravity) / Total Points * Depth Multiplier
* --------
*/
float BuoyancyForceZ = BasePrimComp->GetMass() / PointDensity * FluidDensity * -Gravity / TotalPoints * DepthMultiplier;
//Experimental velocity damping using VelocityAtPoint.
FVector DampingForce = -GetUnrealVelocityAtPoint(BasePrimComp, worldTestPoint) * VelocityDamper * BasePrimComp->GetMass() * DepthMultiplier;
//Experimental xy wave force
if (EnableWaveForces)
{
DampingForce += BasePrimComp->GetMass() * FVector2D(waveHeight.X, waveHeight.Y).Size() * FVector(OceanManager->GlobalWaveDirection.X, OceanManager->GlobalWaveDirection.Y, 0) * WaveForceMultiplier / TotalPoints;
//float waveVelocity = FMath::Clamp(GetUnrealVelocityAtPoint(BasePrimComp, worldTestPoint).Z, -20.f, 150.f) * (1 - DepthMultiplier);
//DampingForce += OceanManager->GlobalWaveDirection * BasePrimComp->GetMass() * waveVelocity * WaveForceMultiplier / TotalPoints;
}
//Add force for this test point
BasePrimComp->AddForceAtLocation(FVector(DampingForce.X, DampingForce.Y, DampingForce.Z + BuoyancyForceZ), worldTestPoint);
}
if (DrawDebugPoints)
{
FColor DebugColor = FLinearColor(0.8, 0.7, 0.2, 0.8).ToRGBE();
if (isUnderwater) { DebugColor = FLinearColor(0, 0.2, 0.7, 0.8).ToRGBE(); } //Blue color underwater, yellow out of watter
DrawDebugSphere(World, worldTestPoint, TestPointRadius, 8, DebugColor);
}
}
//Clamp the velocity to MaxUnderwaterVelocity if there is any point underwater
if (ClampMaxVelocity && PointsUnderWater > 0
&& BasePrimComp->GetPhysicsLinearVelocity().Size() > MaxUnderwaterVelocity)
{
FVector Velocity = BasePrimComp->GetPhysicsLinearVelocity().GetSafeNormal() * MaxUnderwaterVelocity;
BasePrimComp->SetPhysicsLinearVelocity(Velocity);
}
//Update damping based on number of underwater test points
BasePrimComp->SetLinearDamping(_baseLinearDamping + FluidLinearDamping / TotalPoints * PointsUnderWater);
BasePrimComp->SetAngularDamping(_baseAngularDamping + FluidAngularDamping / TotalPoints * PointsUnderWater);
}
