//Calculates global transform of the node.
//This function was taken from FBX SDK/Smaples/Transformations. Originaly it did not take into account AxisSystem, so the corrections to use AxisSystem was added.
//Has the fbx sdk equivalent pNode.EvaluateGlobalTransform();
//
//Note: FBX Documentation for ConvertScene states - "The adjustment will affect the translation animation curves and the objects pivots values
//(the rotation transformation is applied as a pre-rotation transform therefore the rotation animation curves do not need to be transformed)"
//But ConvertScene, does not realy change node.PreRotation, these changes are in the matrix : node.GetScene().GetGlobalSettings().GetAxisSystem().GetMatrix
//
/*
* Terminology:
* Suffix "M" means this is a matrix, suffix "V" means it is a vector.
* T is translation.
* R is rotation.
* S is scaling.
* SH is shear.
* GlobalRM(x) means the Global Rotation Matrix of node "x".
* GlobalRM(P(x)) means the Global Rotation Matrix of the parent node of node "x".
* All other transforms are described in the similar way.
*
* The algorithm description:
* To calculate global transform of a node x according to different InheritType,
* we need to calculate GlobalTM(x) and [GlobalRM(x) * (GlobalSHM(x) * GlobalSM(x))] separately.
* GlobalM(x) = GlobalTM(x) * [GlobalRM(x) * (GlobalSHM(x) * GlobalSM(x))];
*
* InhereitType = RrSs:
* GlobalRM(x) * (GlobalSHM(x) * GlobalSM(x)) = GlobalRM(P(x)) * LocalRM(x) * [GlobalSHM(P(x)) * GlobalSM(P(x))] * LocalSM(x);
*
* InhereitType = RSrs:
* GlobalRM(x) * (GlobalSHM(x) * GlobalSM(x)) = GlobalRM(P(x)) * [GlobalSHM(P(x)) * GlobalSM(P(x))] * LocalRM(x) * LocalSM(x);
*
* InhereitType = Rrs:
* GlobalRM(x) * (GlobalSHM(x) * GlobalSM(x)) = GlobalRM(P(x)) * LocalRM(x) * LocalSM(x);
*
* LocalM(x)= TM(x) * RoffsetM(x) * RpivotM(x) * RpreM(x) * RM(x) * RpostM(x) * RpivotM(x)^-1 * SoffsetM(x) *SpivotM(x) * SM(x) * SpivotM(x)^-1
* LocalTWithAllPivotAndOffsetInformationV(x) = Local(x).GetT();
* GlobalTV(x) = GlobalM(P(x)) * LocalTWithAllPivotAndOffsetInformationV(x);
*
* Notice: FBX SDK does not support shear yet, so all local transform won't have shear.
* However, global transform might bring in shear by combine the global transform of node in higher hierarchy.
* For example, if you scale the parent by a non-uniform scale and then rotate the child node, then a shear will
* be generated on the child node's global transform.
* In this case, we always compensates shear and store it in the scale matrix too according to following formula:
* Shear*Scaling = RotationMatrix.Inverse * TranslationMatrix.Inverse * WholeTranformMatrix
*/
// ReSharper disable InconsistentNaming
static FbxAMatrix CalculateGlobalTransform(FbxNode node)
{
if (node == null)
{
var ret = new FbxAMatrix();
ret.SetIdentity();
return(ret);
}
var lTranlationM = new FbxAMatrix();
var lScalingM = new FbxAMatrix();
var lScalingPivotM = new FbxAMatrix();
var lScalingOffsetM = new FbxAMatrix();
var lRotationOffsetM = new FbxAMatrix();
var lRotationPivotM = new FbxAMatrix();
var lPreRotationM = new FbxAMatrix();
var lRotationM = new FbxAMatrix();
var lPostRotationM = new FbxAMatrix();
FbxAMatrix lParentGX = new FbxAMatrix();
FbxAMatrix lGlobalT = new FbxAMatrix();
FbxAMatrix lGlobalRS = new FbxAMatrix();
// Construct translation matrix
FbxVector4 lTranslation = new FbxVector4(node.LclTranslation.Get()); //The fourth component of this object is assigned 1.
lTranlationM.SetT(lTranslation);
// Construct rotation matrices
FbxVector4 lRotation = new FbxVector4(node.LclRotation.Get());
FbxVector4 lPreRotation = new FbxVector4(node.PreRotation.Get());
FbxVector4 lPostRotation = new FbxVector4(node.PostRotation.Get());
lRotationM.SetR(lRotation);
lPreRotationM.SetR(lPreRotation);
lPostRotationM.SetR(lPostRotation);
// Construct scaling matrix
FbxVector4 lScaling = new FbxVector4(node.LclScaling.Get());
lScalingM.SetS(lScaling);
// Construct offset and pivot matrices
FbxVector4 lScalingOffset = new FbxVector4(node.ScalingOffset.Get());
FbxVector4 lScalingPivot = new FbxVector4(node.ScalingPivot.Get());
FbxVector4 lRotationOffset = new FbxVector4(node.RotationOffset.Get());
FbxVector4 lRotationPivot = new FbxVector4(node.RotationPivot.Get());
lScalingOffsetM.SetT(lScalingOffset);
lScalingPivotM.SetT(lScalingPivot);
lRotationOffsetM.SetT(lRotationOffset);
lRotationPivotM.SetT(lRotationPivot);
// Calculate the global transform matrix of the parent node
FbxNode lParentNode = node.GetParent();
if (lParentNode != null)
{
//Children of the root node must take into account the axis matrix.
//Warning: this function CalculateGlobalTransform was taken from FBX SDK/Smaples/Transformations. Originaly it did not take into account AxisSystem
if (lParentNode.GetParent() == null)
{
FbxAMatrix axisMarix = new FbxAMatrix();
node.GetScene().GetGlobalSettings().GetAxisSystem().GetMatrix(axisMarix);
lPreRotationM = axisMarix.mul(lPreRotationM);
}
lParentGX = CalculateGlobalTransform(lParentNode);
}
else
{
lParentGX.SetIdentity();
}
//Construct Global Rotation
FbxAMatrix lParentGRM = new FbxAMatrix();
FbxVector4 lParentGR = lParentGX.GetR();
lParentGRM.SetR(lParentGR);
var lLRM = lPreRotationM.mul(lRotationM).mul(lPostRotationM);
//Construct Global Shear*Scaling
//FBX SDK does not support shear, to patch this, we use:
//Shear*Scaling = RotationMatrix.Inverse * TranslationMatrix.Inverse * WholeTranformMatrix
FbxAMatrix lParentTM = new FbxAMatrix();
FbxVector4 lParentGT = lParentGX.GetT();
lParentTM.SetT(lParentGT);
var lParentGRSM = lParentTM.Inverse().mul(lParentGX);
var lParentGSM = lParentGRM.Inverse().mul(lParentGRSM);
var lLSM = lScalingM;
//Do not consider translation now
FbxTransform.EInheritType lInheritType = node.InheritType.Get();
if (lInheritType == FbxTransform.EInheritType.eInheritRrSs)
{
lGlobalRS = lParentGRM.mul(lLRM).mul(lParentGSM).mul(lLSM);
}
else if (lInheritType == FbxTransform.EInheritType.eInheritRSrs)
{
lGlobalRS = lParentGRM.mul(lParentGSM).mul(lLRM).mul(lLSM);
}
else if (lInheritType == FbxTransform.EInheritType.eInheritRrs)
{
if (lParentNode != null)
{
FbxAMatrix lParentLSM = new FbxAMatrix();
FbxVector4 lParentLS = new FbxVector4(lParentNode.LclScaling.Get());
lParentLSM.SetS(lParentLS);
FbxAMatrix lParentGSM_noLocal = lParentGSM.mul(lParentLSM.Inverse());
lGlobalRS = lParentGRM.mul(lLRM).mul(lParentGSM_noLocal).mul(lLSM);
}
else
{
lGlobalRS = lParentGRM.mul(lLRM).mul(lLSM);
}
}
else
{
FbxImportLog.LogError(node, "error, unknown inherit type!");
}
// Construct translation matrix
// Calculate the local transform matrix
var lTransform = lTranlationM.mul(lRotationOffsetM).mul(lRotationPivotM).mul(lPreRotationM).mul(lRotationM).mul(lPostRotationM)
.mul(lRotationPivotM.Inverse()).mul(lScalingOffsetM).mul(lScalingPivotM).mul(lScalingM).mul(lScalingPivotM.Inverse());
FbxVector4 lLocalTWithAllPivotAndOffsetInfo = lTransform.GetT();
// Calculate global translation vector according to:
// GlobalTranslation = ParentGlobalTransform * LocalTranslationWithPivotAndOffsetInfo
FbxVector4 lGlobalTranslation = lParentGX.MultT(lLocalTWithAllPivotAndOffsetInfo);
lGlobalT.SetT(lGlobalTranslation);
//Construct the whole global transform
lTransform = lGlobalT.mul(lGlobalRS);
return(lTransform);
}