void FAnimNode_LookAt::EvaluateBoneTransforms(USkeletalMeshComponent* SkelComp, const FBoneContainer& RequiredBones, FA2CSPose& MeshBases, TArray<FBoneTransform>& OutBoneTransforms)
{
check(OutBoneTransforms.Num() == 0);
FTransform ComponentBoneTransform = MeshBases.GetComponentSpaceTransform(BoneToModify.BoneIndex);
// get target location
FVector TargetLocationInComponentSpace;
if (LookAtBone.IsValid(RequiredBones))
{
FTransform LookAtTransform = MeshBases.GetComponentSpaceTransform(LookAtBone.BoneIndex);
TargetLocationInComponentSpace = LookAtTransform.GetLocation();
}
else
{
TargetLocationInComponentSpace = SkelComp->ComponentToWorld.InverseTransformPosition(LookAtLocation);
}
CurrentLookAtLocation = TargetLocationInComponentSpace;
// lookat vector
FVector LookAtVector = GetAlignVector(ComponentBoneTransform, LookAtAxis);
// flip to target vector if it wasnt negative
bool bShouldFlip = LookAtAxis == EAxisOption::X_Neg || LookAtAxis == EAxisOption::Y_Neg || LookAtAxis == EAxisOption::Z_Neg;
FVector ToTarget = CurrentLookAtLocation - ComponentBoneTransform.GetLocation();
ToTarget.Normalize();
if (bShouldFlip)
{
ToTarget *= -1.f;
}
// get delta rotation
FQuat DeltaRot = FQuat::FindBetween(LookAtVector, ToTarget);
// transform current rotation to delta rotation
FQuat CurrentRot = ComponentBoneTransform.GetRotation();
FQuat NewRotation = DeltaRot * CurrentRot;
ComponentBoneTransform.SetRotation(NewRotation);
OutBoneTransforms.Add( FBoneTransform(BoneToModify.BoneIndex, ComponentBoneTransform) );
}
void FAnimNode_Trail::EvaluateBoneTransforms(USkeletalMeshComponent* SkelComp, const FBoneContainer& RequiredBones, FA2CSPose& MeshBases, TArray<FBoneTransform>& OutBoneTransforms)
{
check(OutBoneTransforms.Num() == 0);
if( ChainLength < 2 )
{
return;
}
// The incoming BoneIndex is the 'end' of the spline chain. We need to find the 'start' by walking SplineLength bones up hierarchy.
// Fail if we walk past the root bone.
int32 WalkBoneIndex = TrailBone.BoneIndex;
TArray<int32> ChainBoneIndices;
ChainBoneIndices.AddZeroed(ChainLength);
ChainBoneIndices[ChainLength - 1] = WalkBoneIndex;
for (int32 i = 1; i < ChainLength; i++)
{
// returns to avoid a crash
// @TODO : shows an error message why failed
if (WalkBoneIndex == 0)
{
return;
}
// Get parent bone.
WalkBoneIndex = RequiredBones.GetParentBoneIndex(WalkBoneIndex);
//Insert indices at the start of array, so that parents are before children in the array.
int32 TransformIndex = ChainLength - (i + 1);
ChainBoneIndices[TransformIndex] = WalkBoneIndex;
}
OutBoneTransforms.AddZeroed(ChainLength);
// If we have >0 this frame, but didn't last time, record positions of all the bones.
// Also do this if number has changed or array is zero.
bool bHasValidStrength = (Alpha > 0.f);
if(TrailBoneLocations.Num() != ChainLength || (bHasValidStrength && !bHadValidStrength))
{
TrailBoneLocations.Empty();
TrailBoneLocations.AddZeroed(ChainLength);
for(int32 i=0; i<ChainBoneIndices.Num(); i++)
{
int32 ChildIndex = ChainBoneIndices[i];
FTransform ChainTransform = MeshBases.GetComponentSpaceTransform(ChildIndex);
TrailBoneLocations[i] = ChainTransform.GetTranslation();
}
OldLocalToWorld = SkelComp->GetTransformMatrix();
}
bHadValidStrength = bHasValidStrength;
// transform between last frame and now.
FMatrix OldToNewTM = OldLocalToWorld * SkelComp->GetTransformMatrix().InverseFast();
// Add fake velocity if present to all but root bone
if(!FakeVelocity.IsZero())
{
FVector FakeMovement = -FakeVelocity * ThisTimstep;
if (bActorSpaceFakeVel && SkelComp->GetOwner())
{
const FTransform BoneToWorld(SkelComp->GetOwner()->GetActorRotation(), SkelComp->GetOwner()->GetActorLocation());
FakeMovement = BoneToWorld.TransformVector(FakeMovement);
}
FakeMovement = SkelComp->GetTransformMatrix().InverseTransformVector(FakeMovement);
// Then add to each bone
for(int32 i=1; i<TrailBoneLocations.Num(); i++)
{
TrailBoneLocations[i] += FakeMovement;
}
}
// Root bone of trail is not modified.
int32 RootIndex = ChainBoneIndices[0];
FTransform ChainTransform = MeshBases.GetComponentSpaceTransform(RootIndex);
OutBoneTransforms[0] = FBoneTransform(RootIndex, ChainTransform);
TrailBoneLocations[0] = ChainTransform.GetTranslation();
// Starting one below head of chain, move bones.
for(int32 i=1; i<ChainBoneIndices.Num(); i++)
{
// Parent bone position in component space.
int32 ParentIndex = ChainBoneIndices[i-1];
FVector ParentPos = TrailBoneLocations[i-1];
FVector ParentAnimPos = MeshBases.GetComponentSpaceTransform(ParentIndex).GetTranslation();
// Child bone position in component space.
int32 ChildIndex = ChainBoneIndices[i];
FVector ChildPos = OldToNewTM.TransformPosition(TrailBoneLocations[i]); // move from 'last frames component' frame to 'this frames component' frame
FVector ChildAnimPos = MeshBases.GetComponentSpaceTransform(ChildIndex).GetTranslation();
// Desired parent->child offset.
FVector TargetDelta = (ChildAnimPos - ParentAnimPos);
// Desired child position.
FVector ChildTarget = ParentPos + TargetDelta;
// Find vector from child to target
FVector Error = ChildTarget - ChildPos;
// Calculate how much to push the child towards its target
float Correction = FMath::Clamp<float>(ThisTimstep * TrailRelaxation, 0.f, 1.f);
// Scale correction vector and apply to get new world-space child position.
TrailBoneLocations[i] = ChildPos + (Error * Correction);
// If desired, prevent bones stretching too far.
if(bLimitStretch)
{
float RefPoseLength = TargetDelta.Size();
FVector CurrentDelta = TrailBoneLocations[i] - TrailBoneLocations[i-1];
float CurrentLength = CurrentDelta.Size();
// If we are too far - cut it back (just project towards parent particle).
if( (CurrentLength - RefPoseLength > StretchLimit) && CurrentLength > SMALL_NUMBER )
{
FVector CurrentDir = CurrentDelta / CurrentLength;
TrailBoneLocations[i] = TrailBoneLocations[i-1] + (CurrentDir * (RefPoseLength + StretchLimit));
}
}
// Modify child matrix
OutBoneTransforms[i] = FBoneTransform(ChildIndex, MeshBases.GetComponentSpaceTransform(ChildIndex));
OutBoneTransforms[i].Transform.SetTranslation(TrailBoneLocations[i]);
// Modify rotation of parent matrix to point at this one.
// Calculate the direction that parent bone is currently pointing.
FVector CurrentBoneDir = OutBoneTransforms[i-1].Transform.TransformVector( GetAlignVector(ChainBoneAxis, bInvertChainBoneAxis) );
CurrentBoneDir = CurrentBoneDir.SafeNormal(SMALL_NUMBER);
// Calculate vector from parent to child.
FVector NewBoneDir = FVector(OutBoneTransforms[i].Transform.GetTranslation() - OutBoneTransforms[i - 1].Transform.GetTranslation()).SafeNormal(SMALL_NUMBER);
// Calculate a quaternion that gets us from our current rotation to the desired one.
FQuat DeltaLookQuat = FQuat::FindBetween(CurrentBoneDir, NewBoneDir);
FTransform DeltaTM( DeltaLookQuat, FVector(0.f) );
// Apply to the current parent bone transform.
FTransform TmpMatrix = FTransform::Identity;
TmpMatrix.CopyRotationPart(OutBoneTransforms[i - 1].Transform);
TmpMatrix = TmpMatrix * DeltaTM;
OutBoneTransforms[i - 1].Transform.CopyRotationPart(TmpMatrix);
}
// For the last bone in the chain, use the rotation from the bone above it.
OutBoneTransforms[ChainLength - 1].Transform.CopyRotationPart(OutBoneTransforms[ChainLength - 2].Transform);
// Update OldLocalToWorld
OldLocalToWorld = SkelComp->GetTransformMatrix();
}
void FAnimNode_LookAt::EvaluateBoneTransforms(USkeletalMeshComponent* SkelComp, FCSPose<FCompactPose>& MeshBases, TArray<FBoneTransform>& OutBoneTransforms)
{
check(OutBoneTransforms.Num() == 0);
const FBoneContainer& BoneContainer = MeshBases.GetPose().GetBoneContainer();
const FCompactPoseBoneIndex ModifyBoneIndex = BoneToModify.GetCompactPoseIndex(BoneContainer);
FTransform ComponentBoneTransform = MeshBases.GetComponentSpaceTransform(ModifyBoneIndex);
// get target location
FVector TargetLocationInComponentSpace;
if (LookAtBone.IsValid(BoneContainer))
{
const FTransform& LookAtTransform = MeshBases.GetComponentSpaceTransform(LookAtBone.GetCompactPoseIndex(BoneContainer));
TargetLocationInComponentSpace = LookAtTransform.GetLocation();
}
else
{
TargetLocationInComponentSpace = SkelComp->ComponentToWorld.InverseTransformPosition(LookAtLocation);
}
FVector OldCurrentTargetLocation = CurrentTargetLocation;
FVector NewCurrentTargetLocation = TargetLocationInComponentSpace;
if ((NewCurrentTargetLocation - OldCurrentTargetLocation).SizeSquared() > InterpolationTriggerThreashold*InterpolationTriggerThreashold)
{
if (AccumulatedInterpoolationTime >= InterpolationTime)
{
// reset current Alpha, we're starting to move
AccumulatedInterpoolationTime = 0.f;
}
PreviousTargetLocation = OldCurrentTargetLocation;
CurrentTargetLocation = NewCurrentTargetLocation;
}
else if (InterpolationTriggerThreashold == 0.f)
{
CurrentTargetLocation = NewCurrentTargetLocation;
}
if (InterpolationTime > 0.f)
{
float CurrentAlpha = AccumulatedInterpoolationTime/InterpolationTime;
if (CurrentAlpha < 1.f)
{
float BlendAlpha = AlphaToBlendType(CurrentAlpha, GetInterpolationType());
CurrentLookAtLocation = FMath::Lerp(PreviousTargetLocation, CurrentTargetLocation, BlendAlpha);
}
}
else
{
CurrentLookAtLocation = CurrentTargetLocation;
}
if (bEnableDebug)
{
UWorld* World = SkelComp->GetWorld();
DrawDebugData(World, SkelComp->GetComponentToWorld(), ComponentBoneTransform.GetLocation(), PreviousTargetLocation, FColor(0, 255, 0));
DrawDebugData(World, SkelComp->GetComponentToWorld(), ComponentBoneTransform.GetLocation(), CurrentTargetLocation, FColor(255, 0, 0));
DrawDebugData(World, SkelComp->GetComponentToWorld(), ComponentBoneTransform.GetLocation(), CurrentLookAtLocation, FColor(0, 0, 255));
}
// lookat vector
FVector LookAtVector = GetAlignVector(ComponentBoneTransform, LookAtAxis);
// flip to target vector if it wasnt negative
bool bShouldFlip = LookAtAxis == EAxisOption::X_Neg || LookAtAxis == EAxisOption::Y_Neg || LookAtAxis == EAxisOption::Z_Neg;
FVector ToTarget = CurrentLookAtLocation - ComponentBoneTransform.GetLocation();
ToTarget.Normalize();
if (bShouldFlip)
{
ToTarget *= -1.f;
}
if ( LookAtClamp > ZERO_ANIMWEIGHT_THRESH )
{
float LookAtClampInRadians = FMath::DegreesToRadians(LookAtClamp);
float DiffAngle = FMath::Acos(FVector::DotProduct(LookAtVector, ToTarget));
if (LookAtClampInRadians > 0.f && DiffAngle > LookAtClampInRadians)
{
FVector OldToTarget = ToTarget;
FVector DeltaTarget = ToTarget-LookAtVector;
float Ratio = LookAtClampInRadians/DiffAngle;
DeltaTarget *= Ratio;
ToTarget = LookAtVector + DeltaTarget;
ToTarget.Normalize();
// UE_LOG(LogAnimation, Warning, TEXT("Recalculation required - old target %f, new target %f"),
// FMath::RadiansToDegrees(FMath::Acos(FVector::DotProduct(LookAtVector, OldToTarget))), FMath::RadiansToDegrees(FMath::Acos(FVector::DotProduct(LookAtVector, ToTarget))));
}
}
FQuat DeltaRot;
// if want to use look up,
if (bUseLookUpAxis)
{
// find look up vector in local space
FVector LookUpVector = GetAlignVector(ComponentBoneTransform, LookUpAxis);
// project target to the plane
FVector NewTarget = FVector::VectorPlaneProject(ToTarget, LookUpVector);
NewTarget.Normalize();
DeltaRot = FQuat::FindBetween(LookAtVector, NewTarget);
}
else
{
DeltaRot = FQuat::FindBetween(LookAtVector, ToTarget);
}
// transform current rotation to delta rotation
FQuat CurrentRot = ComponentBoneTransform.GetRotation();
FQuat NewRotation = DeltaRot * CurrentRot;
ComponentBoneTransform.SetRotation(NewRotation);
OutBoneTransforms.Add(FBoneTransform(ModifyBoneIndex, ComponentBoneTransform));
}