From b7c9fabdf5e44278ae7204de2e587bb89910309c Mon Sep 17 00:00:00 2001
From: BlueRose <378100977@qq.com>
Date: Mon, 6 Nov 2023 22:17:01 +0800
Subject: [PATCH] vault backup: 2023-11-06 22:17:01

---
 .../Animation/UE5动画重定向核心逻辑笔记.md    | 52 ++++++++++++++++---
 1 file changed, 44 insertions(+), 8 deletions(-)

diff --git a/03-UnrealEngine/Animation/UE5动画重定向核心逻辑笔记.md b/03-UnrealEngine/Animation/UE5动画重定向核心逻辑笔记.md
index 9c4acc3..ae02ac4 100644
--- a/03-UnrealEngine/Animation/UE5动画重定向核心逻辑笔记.md
+++ b/03-UnrealEngine/Animation/UE5动画重定向核心逻辑笔记.md
@@ -43,14 +43,50 @@ FRootRetargeter::EncodePose():
 
 FRootRetargeter::DecodePose():
 ```c++
-// InitialTransform 为重定向Pose计算出的数值，通过比值计算出Target的Current数值
-const FTransform InitialTransform = SourceSkeleton.RetargetGlobalPose[Source.BoneIndex];
-float InitialHeight = InitialTransform.GetTranslation().Z;
-Source.InitialHeightInverse = 1.0f / InitialHeight;
-Source.CurrentPositionNormalized = Source.CurrentPosition * Source.InitialHeightInverse;
-
-// generate basic retarget root position by scaling the normalized position by root height  
-const FVector RetargetedPosition = Source.CurrentPositionNormalized * Target.InitialHeight;
+FVector Position;  
+{  
+    // 关键：InitialTransform 为重定向Pose计算出的数值，通过比值计算出Target的Current数值
+    const FVector RetargetedPosition = Source.CurrentPositionNormalized * Target.InitialHeight;  
+    // 根据RetargetSetting中设置的BlendToSourceWeights与BlendToSource，与SourcePosition进行混合。
+    Position = FMath::Lerp(RetargetedPosition, Source.CurrentPosition, Settings.BlendToSource*Settings.BlendToSourceWeights);  
+  
+    // 应用vertical / horizontal的缩放  
+    FVector ScaledRetargetedPosition = Position;  
+    ScaledRetargetedPosition.Z *= Settings.ScaleVertical;  
+    const FVector HorizontalOffset = (ScaledRetargetedPosition - Target.InitialPosition) * FVector(Settings.ScaleHorizontal, Settings.ScaleHorizontal, 1.0f);  
+    Position = Target.InitialPosition + HorizontalOffset;  
+    // 应用RetargetSetting中Position偏移。
+    Position += Settings.TranslationOffset;  
+  
+    // blend with alpha  
+    Position = FMath::Lerp(Target.InitialPosition, Position, Settings.TranslationAlpha);  
+  
+    // 记录偏差
+    Target.RootTranslationDelta = Position - RetargetedPosition;  
+}  
+  
+FQuat Rotation;  
+{  
+    // calc offset between initial source/target root rotations  
+    const FQuat RotationDelta = Source.CurrentRotation * Source.InitialRotation.Inverse();  
+    // add retarget pose delta to the current source rotation  
+    const FQuat RetargetedRotation = RotationDelta * Target.InitialRotation;  
+  
+    // add static rotation offset  
+    Rotation = RetargetedRotation * Settings.RotationOffset.Quaternion();  
+  
+    // blend with alpha  
+    Rotation = FQuat::FastLerp(Target.InitialRotation, Rotation, Settings.RotationAlpha);  
+    Rotation.Normalize();  
+  
+    // record the delta created by all the modifications made to the root rotation  
+    Target.RootRotationDelta = RetargetedRotation * Target.InitialRotation.Inverse();  
+}  
+  
+// apply to target  
+FTransform& TargetRootTransform = OutTargetGlobalPose[Target.BoneIndex];  
+TargetRootTransform.SetTranslation(Position);  
+TargetRootTransform.SetRotation(Rotation);
 ```
 ## RunFKRetarget()
 FChainEncoderFK::EncodePose():