FVector3d
BilinearInterp
( const FVector3d& v00, const FVector3d& v10, const FVector3d& v11, const FVector3d& v01, double tx, double ty)
FVector2d
( const FVector2d& v00, const FVector2d& v10, const FVector2d& v11, const FVector2d& v01, double tx, double ty)
FVector2f
( const FVector2f& v00, const FVector2f& v10, const FVector2f& v11, const FVector2f& v01, float tx, float ty)