BlueRoseNote/03-UnrealEngine/Animation/UE5动画重定向 & FBX文件格式.md

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title	date	excerpt	tags	rating
UE5动画重定向笔记	2023-08-18 18:08:12			⭐

ConvertAnimation()

主要逻辑位于UAnimationEditorUtilityLibrary::ConvertAnimation()或者FIKRetargetBatchOperation::ConvertAnimation()。核心重定向逻辑为UIKRetargetProcessor::RunRetargeter()。

RunRootRetarget()

FRootRetargeter::EncodePose(): 取得输入的根骨骼Transform数据并给FRootSource Source赋值。

FRootRetargeter::DecodePose():

// 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;

RunFKRetarget()

FChainEncoderFK::EncodePose(): 从骨骼链拷贝全局输入到CurrentGlobalTransforms

FChainDecoderFK::DecodePose():

RunIKRetarget()

RunPoleVectorMatching()

UIKRetargetProcessor

FBX SDK setup for Qt

https://help.autodesk.com/view/FBX/2020/ENU/?guid=FBX_Developer_Help_welcome_to_the_fbx_sdk_html

使用之前建议仔细查看文档。FBX Sdk有三种库，分别为动态链接库(dll + lib)、静态链接库(/MD)、静态链接库(/MT)。

• 动态链接库：使用Qt的导入库功能，导入动态库之后，只需要再添加一行DEFINES += FBXSDK_SHARED即可。例如：

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

CONFIG += c++17
DEFINES += FBXSDK_SHARED
# You can make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

SOURCES += \
    Common/Common.cpp \
    main.cpp \
    mainwindow.cpp

HEADERS += \
    Common/Common.h \
    mainwindow.h

FORMS += \
    mainwindow.ui

# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target

win32:CONFIG(release, debug|release): LIBS += -L$$PWD/FBXSdk/lib/vs2022/x64/release/ -llibfbxsdk
else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/FBXSdk/lib/vs2022/x64/debug/ -llibfbxsdk

INCLUDEPATH += $$PWD/FBXSdk/lib/vs2022/x64/debug
DEPENDPATH += $$PWD/FBXSdk/lib/vs2022/x64/debug

INCLUDEPATH += $$PWD/FBXSdk/include

• 静态链接库(/MD)：使用Qt的导入库功能，导入静态库之后，
• 静态链接库(/MT)：使用Qt的导入库功能，导入静态库之后，

Qt相关设置添加

https://blog.csdn.net/libaineu2004/article/details/105718847 Qt在pro中设置运行时库MT、MTd、MD、MDd，重点关注QMAKE_CFLAGS

多线程调试Dll (/MDd) 对应的是MD_DynamicDebug 多线程Dll (/MD) 对应的是MD_DynamicRelease 多线程(/MT) 对应的是MD_StaticRelease 多线程(/MTd)对应的是MD_StaticDebug

 /NODEFAULTLIB:library

win32:CONFIG(release, debug|release): LIBS += -L$$PWD/../LIBRARYNAME/Lib/ -lLIBRARY /NODEFAULTLIB:library

Ubuntu安装需要额外安装（Qt）

sudo apt install --reinstall libgl-dev

FBX结构

FBX SDK场景图是通过FbxScene类抽象出来的。场景被组织为节点层次结构 ( FbxNode)。场景的根节点通过 访问FbxScene::GetRootNode()。场景元素（例如网格、灯光或相机）是通过将FbxNode与 的子类组合来定义的FbxNodeAttribute。

使用Ansii方式输出就可以使用vscode直接查看内部数据结构。

• GlobalMaterial：世界坐标矩阵
• LocalMaterial：相对空间矩阵

动画

• 动画堆栈 ( FbxAnimStack)：动画数据最顶层容器，每一个AnimStack可以视为一个镜头，包含多个FbxAnimLayer。
• 动画层 ( FbxAnimLayer)：每个AnimLayer中可以包含多个FbxAnimCurve。
• 动画曲线节点 ( FbxAnimCurveNode)
• 动画曲线 ( FbxAnimCurve) ：动画以曲线的方式存在。可以针对骨骼的Location、Rotation分别添加曲线。
• 动画曲线关键点 ( FbxAnimCurveKey)：动画关键帧。

每个动画数据都存在对应的节点的属性中（Maya中可以给Shape的属性K帧），可以通过类似lAnimCurve = pNode->LclTranslation.GetCurve(pAnimLayer, FBXSDK_CURVENODE_COMPONENT_Y);的方式取得动画曲线。

UE导出的FBX相关属性为：

	AnimationStack: 1767515526080, "AnimStack::Unreal Take", "" {
		Properties70:  {
			P: "Description", "KString", "", "", "Animation Take for Unreal."
			P: "LocalStop", "KTime", "Time", "",183205094709
		}
	}
	
	AnimationLayer: 1770224712128, "AnimLayer::Base Layer", "" {
	}
	
	NodeAttribute: 1767517959504, "NodeAttribute::Root", "Root" {
		TypeFlags: "Null", "Skeleton", "Root"
	}
	NodeAttribute: 1767517960848, "NodeAttribute::Pelvis", "LimbNode" {
		TypeFlags: "Skeleton"
	}
	NodeAttribute: 1767517959696, "NodeAttribute::L_Hip", "LimbNode" {
		TypeFlags: "Skeleton"
	}
	NodeAttribute: 1767517960080, "NodeAttribute::L_Knee", "LimbNode" {
		TypeFlags: "Skeleton"
	}
	
AnimationCurve: 1770213770432, "AnimCurve::", "" {
		Default: 0
		KeyVer: 4009
		KeyTime: *120 {
			a: 0,1539538600,3079077200,4618615800,6158154400,7697693000,9237231600,10776770200,12316308800,13855847400,15395386000,16934924600,18474463200,20014001800,21553540400,23093079000,24632617600,26172156200,27711694800,29251233400,30790772000,32330310600,33869849200,35409387800,36948926400,38488465000,40028003600,41567542200,43107080800,44646619400,46186158000,47725696600,49265235200,50804773800,52344312400,53883851000,55423389600,56962928200,58502466800,60042005400,61581544000,63121082600,64660621200,66200159800,67739698400,69279237000,70818775600,72358314200,73897852800,75437391400,76976930000,78516468600,80056007200,81595545800,83135084400,84674623000,86214161600,87753700200,89293238800,90832777400,92372316000,93911854600,95451393200,96990931800,98530470400,100070009000,101609547600,103149086200,104688624800,106228163400,107767702000,109307240600,110846779200,112386317800,113925856400,115465395000,117004933600,118544472200,120084010800,121623549400,123163088000,124702626600,126242165200,127781703800,129321242400,130860781000,132400319600,133939858200,135479396800,137018935400,138558474000,140098012600,141637551200,143177089800,144716628400,146256167000,147795705600,149335244200,150874782800,152414321400,153953860000,155493398600,157032937200,158572475800,160112014400,161651553000,163191091600,164730630200,166270168800,167809707400,169349246000,170888784600,172428323200,173967861800,175507400400,177046939000,178586477600,180126016200,181665554800,183205093400
		} 
		KeyValueFloat: *120 {
			a: -0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0,-0
		} 
		;KeyAttrFlags: Cubic|TangeantAuto|GenericTimeIndependent, Constant|ConstantStandard
		KeyAttrFlags: *2 {
			a: 8456,8194
		} 
		;KeyAttrDataFloat: RightAuto:0, NextLeftAuto:0; RightSlope:0, NextLeftSlope:0, RightWeight:0.333333, NextLeftWeight:0.333333, RightVelocity:0, NextLeftVelocity:0
		KeyAttrDataFloat: *8 {
			a: 0,0,218434821,0,0,0,218434821,0
		} 
		KeyAttrRefCount: *2 {
			a: 119,1
		} 
	}
	AnimationCurve: 1770213768992, "AnimCurve::", "" {
		Default: 0
		KeyVer: 4009
		KeyTime: *120 {
			a: 0,1539538600,3079077200,4618615800,6158154400,7697693000,9237231600,10776770200,12316308800,13855847400,15395386000,16934924600,18474463200,20014001800,21553540400,23093079000,24632617600,26172156200,27711694800,29251233400,30790772000,32330310600,33869849200,35409387800,36948926400,38488465000,40028003600,41567542200,43107080800,44646619400,46186158000,47725696600,49265235200,50804773800,52344312400,53883851000,55423389600,56962928200,58502466800,60042005400,61581544000,63121082600,64660621200,66200159800,67739698400,69279237000,70818775600,72358314200,73897852800,75437391400,76976930000,78516468600,80056007200,81595545800,83135084400,84674623000,86214161600,87753700200,89293238800,90832777400,92372316000,93911854600,95451393200,96990931800,98530470400,100070009000,101609547600,103149086200,104688624800,106228163400,107767702000,109307240600,110846779200,112386317800,113925856400,115465395000,117004933600,118544472200,120084010800,121623549400,123163088000,124702626600,126242165200,127781703800,129321242400,130860781000,132400319600,133939858200,135479396800,137018935400,138558474000,140098012600,141637551200,143177089800,144716628400,146256167000,147795705600,149335244200,150874782800,152414321400,153953860000,155493398600,157032937200,158572475800,160112014400,161651553000,163191091600,164730630200,166270168800,167809707400,169349246000,170888784600,172428323200,173967861800,175507400400,177046939000,178586477600,180126016200,181665554800,183205093400
		} 
		KeyValueFloat: *120 {
			a: 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
		} 
		;KeyAttrFlags: Cubic|TangeantAuto|GenericTimeIndependent, Constant|ConstantStandard
		KeyAttrFlags: *2 {
			a: 8456,8194
		} 
		;KeyAttrDataFloat: RightAuto:0, NextLeftAuto:0; RightSlope:0, NextLeftSlope:0, RightWeight:0.333333, NextLeftWeight:0.333333, RightVelocity:0, NextLeftVelocity:0
		KeyAttrDataFloat: *8 {
			a: 0,0,218434821,0,0,0,218434821,0
		} 
		KeyAttrRefCount: *2 {
			a: 119,1
		} 
	}

添加动画关键帧的方式

FbxAnimCurve* lCurve = lRoot->LclRotation.GetCurve(lAnimLayer, FBXSDK_CURVENODE_COMPONENT_Z, true);
if (lCurve)
{
	lCurve->KeyModifyBegin();
	lTime.SetSecondDouble(0.0);
	//添加时间
	lKeyIndex = lCurve->KeyAdd(lTime);
	//添加数值与插值模式
	lCurve->KeySetValue(lKeyIndex, 0.0);
	lCurve->KeySetInterpolation(lKeyIndex, FbxAnimCurveDef::eInterpolationCubic);

	lTime.SetSecondDouble(1.0);
	lKeyIndex = lCurve->KeyAdd(lTime);
	lCurve->KeySetValue(lKeyIndex, 45.0);
	lCurve->KeySetInterpolation(lKeyIndex, FbxAnimCurveDef::eInterpolationCubic);

	lTime.SetSecondDouble(2.0);
	lKeyIndex = lCurve->KeyAdd(lTime);
	lCurve->KeySetValue(lKeyIndex, -45.0);
	lCurve->KeySetInterpolation(lKeyIndex, FbxAnimCurveDef::eInterpolationCubic);

	lTime.SetSecondDouble(3.0);
	lKeyIndex = lCurve->KeyAdd(lTime);
	lCurve->KeySetValue(lKeyIndex, 0.0);
	lCurve->KeySetInterpolation(lKeyIndex, FbxAnimCurveDef::eInterpolationCubic);
	lCurve->KeyModifyEnd();
}

BindPose

遍历所有节点，并对取得GlobalTransform矩阵，最后添加到Pose里。

    // Now create a bind pose with the link list
    if (lClusteredFbxNodes.GetCount())
    {
        // A pose must be named. Arbitrarily use the name of the patch node.
        FbxPose* lPose = FbxPose::Create(pScene,pPatch->GetName());

        // default pose type is rest pose, so we need to set the type as bind pose
        lPose->SetIsBindPose(true);

        for (i=0; i<lClusteredFbxNodes.GetCount(); i++)
        {
            FbxNode*  lKFbxNode   = lClusteredFbxNodes.GetAt(i);
            FbxMatrix lBindMatrix = lKFbxNode->EvaluateGlobalTransform();

            lPose->Add(lKFbxNode, lBindMatrix);
        }

        // Add the pose to the scene
        pScene->AddPose(lPose);
    }

ResetPose

void StoreRestPose(FbxScene* pScene, FbxNode* pSkeletonRoot)
{
    // This example show an arbitrary rest pose assignment.
    // This rest pose will set the bone rotation to the same value 
    // as time 1 second in the first stack of animation, but the 
    // position of the bone will be set elsewhere in the scene.
    FbxString     lNodeName;
    FbxNode*   lKFbxNode;
    FbxMatrix  lTransformMatrix;
    FbxVector4 lT,lR,lS(1.0, 1.0, 1.0);

    // Create the rest pose
    FbxPose* lPose = FbxPose::Create(pScene,"A Bind Pose");

    // Set the skeleton root node to the global position (10, 10, 10)
    // and global rotation of 45deg along the Z axis.
    lT.Set(10.0, 10.0, 10.0);
    lR.Set( 0.0,  0.0, 45.0);

    lTransformMatrix.SetTRS(lT, lR, lS);

    // 添加Root骨骼矩阵到Pose中
    lKFbxNode = pSkeletonRoot;
    lPose->Add(lKFbxNode, lTransformMatrix, false /*GlobalMatrix*/);

    // Set the lLimbNode1 node to the local position of (0, 40, 0)
    // and local rotation of -90deg along the Z axis. This show that
    // you can mix local and global coordinates in a rest pose.
    lT.Set(0.0, 40.0,   0.0);
    lR.Set(0.0,  0.0, -90.0);

    lTransformMatrix.SetTRS(lT, lR, lS);

    // 添加第二个骨骼节点到Pose中
    lKFbxNode = lKFbxNode->GetChild(0);
    lPose->Add(lKFbxNode, lTransformMatrix, true /*LocalMatrix*/);

    // Set the lLimbNode2 node to the local position of (0, 40, 0)
    // and local rotation of 45deg along the Z axis.
    lT.Set(0.0, 40.0, 0.0);
    lR.Set(0.0,  0.0, 45.0);

    lTransformMatrix.SetTRS(lT, lR, lS);

    // Add the skeleton second node to the pose
    lKFbxNode = lKFbxNode->GetChild(0);
    lNodeName = lKFbxNode->GetName();
    lPose->Add(lKFbxNode, lTransformMatrix, true /*LocalMatrix*/);

    // Now add the pose to the scene
    pScene->AddPose(lPose);
}

GlobalSettings

场景的轴系统、系统单位、环境照明和时间设置可以通过FbxScene::GetGlobalSettings()获取FbxGlobalSettings来进行定义。