diff --git a/Source/Ember/Affine2D.cpp b/Source/Ember/Affine2D.cpp
index 083f2a0..b02839a 100644
--- a/Source/Ember/Affine2D.cpp
+++ b/Source/Ember/Affine2D.cpp
@@ -157,6 +157,21 @@ bool Affine2D<T>::IsZero() const
 		   (IsClose<T>(F(), 0));
 }
 
+/// <summary>
+/// Determine whether this affine transform was deliberately set to all empty values.
+/// </summary>
+/// <returns>True if all 6 elements equal zero, else false.</returns>
+template <typename T>
+bool Affine2D<T>::IsEmpty() const
+{
+	return (IsClose<T>(A(), EMPTYFIELD)) &&
+		   (IsClose<T>(B(), EMPTYFIELD)) &&
+		   (IsClose<T>(C(), EMPTYFIELD)) &&
+		   (IsClose<T>(D(), EMPTYFIELD)) &&
+		   (IsClose<T>(E(), EMPTYFIELD)) &&
+		   (IsClose<T>(F(), EMPTYFIELD));
+}
+
 /// <summary>
 /// Rotate this affine transform around its origin by the specified angle in degrees.
 /// </summary>
diff --git a/Source/Ember/Affine2D.h b/Source/Ember/Affine2D.h
index 162d9b8..a96f6c6 100644
--- a/Source/Ember/Affine2D.h
+++ b/Source/Ember/Affine2D.h
@@ -74,6 +74,7 @@ public:
 	void MakeID();
 	bool IsID() const;
 	bool IsZero() const;
+	bool IsEmpty() const;
 	void Rotate(T angle);
 	void Translate(const v2T& v);
 	void RotateScaleXTo(const v2T& v);
diff --git a/Source/Ember/EmberDefines.h b/Source/Ember/EmberDefines.h
index d18279e..cb1c2ed 100644
--- a/Source/Ember/EmberDefines.h
+++ b/Source/Ember/EmberDefines.h
@@ -74,6 +74,7 @@ namespace EmberNs
 #define TMAX std::numeric_limits<T>::max()
 #define FLOAT_MAX_TAN 8388607.0f
 #define FLOAT_MIN_TAN -FLOAT_MAX_TAN
+#define EMPTYFIELD -9999
 typedef std::chrono::high_resolution_clock Clock;
 
 #ifndef byte
diff --git a/Source/Ember/EmberToXml.h b/Source/Ember/EmberToXml.h
index e765e51..5f3e402 100644
--- a/Source/Ember/EmberToXml.h
+++ b/Source/Ember/EmberToXml.h
@@ -493,14 +493,14 @@ private:
 				os << "   <xform weight=\"" << xform.m_Weight << "\" ";
 		}
 
+		if (!doMotion || xform.m_ColorX != EMPTYFIELD) os << "color=\"" << xform.m_ColorX << "\" ";
+		//if (!doMotion || xform.m_ColorY != EMPTYFIELD) os << "color=\"" << xform.m_ColorX << " " << xform.m_ColorY << "\" ";
+		if (!doMotion || xform.m_DirectColor != EMPTYFIELD) os << "var_color=\"" << xform.m_DirectColor << "\" ";
+		if (!doMotion || xform.m_ColorSpeed != EMPTYFIELD) os << "color_speed=\"" << xform.m_ColorSpeed << "\" ";
+		//os << "symmetry=\"" << fabs(xform.m_ColorSpeed - 1) * 2 << "\" ";//Legacy support.
+
 		if (!doMotion)
 		{
-			os << "color=\"" << xform.m_ColorX << "\" ";
-			//os << "color=\"" << xform.m_ColorX << " " << xform.m_ColorY << "\" ";
-			os << "var_color=\"" << xform.m_DirectColor << "\" ";
-			os << "color_speed=\"" << xform.m_ColorSpeed << "\" ";
-			//os << "symmetry=\"" << fabs(xform.m_ColorSpeed - 1) * 2 << "\" ";//Legacy support.
-
 			string s = xform.m_Name;
 
 			std::replace(s.begin(), s.end(), ' ', '_');
@@ -536,20 +536,20 @@ private:
 			}
 		}
 
-		if (!doMotion || (doMotion && !xform.m_Affine.IsZero()))
+		if (!doMotion || (doMotion && !xform.m_Affine.IsZero() && !xform.m_Affine.IsEmpty()))
 		{
 			os << "coefs=\"" << xform.m_Affine.A() << " " << xform.m_Affine.D() << " " << xform.m_Affine.B() << " "
 				 << xform.m_Affine.E() << " " << xform.m_Affine.C() << " " << xform.m_Affine.F() << "\"";
 		}
 
-		if ((!doMotion && !xform.m_Post.IsID()) || (doMotion && !xform.m_Post.IsZero()))
+		if ((!doMotion && !xform.m_Post.IsID()) || (doMotion && !xform.m_Post.IsZero() && !xform.m_Post.IsEmpty()))
 		{
 			os << " post=\"" << xform.m_Post.A() << " " << xform.m_Post.D() << " " << xform.m_Post.B() << " "
 				<< xform.m_Post.E() << " " << xform.m_Post.C() << " " << xform.m_Post.F() << "\"";
 		}
 
 		//Original only printed xaos values that were not 1. Here, print them all out if any are present.
-		if (!isFinal && !doMotion && xform.XaosPresent())
+		if (!isFinal && !doMotion && xform.XaosPresent())//Applying motion to xaos not supported.
 		{
 			os << " chaos=\"";
 
@@ -559,8 +559,7 @@ private:
 			os << "\"";
 		}
 
-		if (!doMotion)
-			os << " opacity=\"" << xform.m_Opacity << "\"";
+		if (!doMotion || xform.m_Opacity != EMPTYFIELD) os << " opacity=\"" << xform.m_Opacity << "\"";
 
 		if (!doMotion && !xform.m_Motion.empty())
 		{
diff --git a/Source/Ember/Xform.h b/Source/Ember/Xform.h
index e7ad1be..8fba52d 100644
--- a/Source/Ember/Xform.h
+++ b/Source/Ember/Xform.h
@@ -32,12 +32,13 @@ class EMBER_API Xform
 {
 public:
 	/// <summary>
-	/// Default constructor which calls Init() to set default values.
-	/// Pre and post affine are defaulted to the identity matrix.
+	/// Default constructor which calls Init() to set default or out of bounds values.
+	/// When useDefaults is true, Pre and post affine are defaulted to the identity matrix.
 	/// </summary>
-	Xform()
+	/// <param name="useDefaults">Use reasonable default if true, else use out of bounds values.</param>
+	Xform(bool useDefaults = true)
 	{
-		Init();
+		Init(useDefaults);
 	}
 
 	/// <summary>
@@ -196,36 +197,73 @@ public:
 
 	/// <summary>
 	/// Init default values.
+	/// Non default values are used to signify an uninitialized state. This is useful for 
+	/// doing motion interpolation where we don't want to apply motion to all fields. By setting
+	/// unreasonable values before parsing, then only assigning the ones the motion tags specified, 
+	/// it is clear which fields are intended to have motion applied to them.
 	/// </summary>
-	void Init()
+	/// <param name="useDefaults">Use reasonable default if true, else use out of bounds values.</param>
+	void Init(bool useDefaults = true)
 	{
 		static size_t count = 0;
 
-		m_Weight = 0;
-		m_ColorSpeed = T(0.5);
-		m_Animate = 1;
-		m_ColorX = T(count & 1);
-		m_ColorY = 0;
-		m_DirectColor = 1;
-		m_Opacity = 1;
+		if (useDefaults)
+		{
+			m_Weight = 0;
+			m_ColorSpeed = T(0.5);
+			m_Animate = 1;
+			m_ColorX = T(count & 1);
+			m_ColorY = 0;
+			m_DirectColor = 1;
+			m_Opacity = 1;
 
-		m_Affine.A(1);
-		m_Affine.B(0);
-		m_Affine.C(0);
-		m_Affine.D(0);
-		m_Affine.E(1);
-		m_Affine.F(0);
+			m_Affine.A(1);
+			m_Affine.B(0);
+			m_Affine.C(0);
+			m_Affine.D(0);
+			m_Affine.E(1);
+			m_Affine.F(0);
 
-		m_Post.A(1);
-		m_Post.B(0);
-		m_Post.C(0);
-		m_Post.D(0);
-		m_Post.E(1);
-		m_Post.F(0);
+			m_Post.A(1);
+			m_Post.B(0);
+			m_Post.C(0);
+			m_Post.D(0);
+			m_Post.E(1);
+			m_Post.F(0);
+
+			m_Wind[0] = 0;
+			m_Wind[1] = 0;
+			m_MotionFreq = 0;
+		}
+		else
+		{
+			m_Weight = EMPTYFIELD;
+			m_ColorSpeed = EMPTYFIELD;
+			m_Animate = EMPTYFIELD;
+			m_ColorX = EMPTYFIELD;
+			m_ColorY = EMPTYFIELD;
+			m_DirectColor = EMPTYFIELD;
+			m_Opacity = EMPTYFIELD;
+
+			m_Affine.A(EMPTYFIELD);
+			m_Affine.B(EMPTYFIELD);
+			m_Affine.C(EMPTYFIELD);
+			m_Affine.D(EMPTYFIELD);
+			m_Affine.E(EMPTYFIELD);
+			m_Affine.F(EMPTYFIELD);
+
+			m_Post.A(EMPTYFIELD);
+			m_Post.B(EMPTYFIELD);
+			m_Post.C(EMPTYFIELD);
+			m_Post.D(EMPTYFIELD);
+			m_Post.E(EMPTYFIELD);
+			m_Post.F(EMPTYFIELD);
+
+			m_Wind[0] = EMPTYFIELD;
+			m_Wind[1] = EMPTYFIELD;
+			m_MotionFreq = EMPTYFIELD;
+		}
 
-		m_Wind[0] = 0;
-		m_Wind[1] = 0;
-		m_MotionFreq = 0;
 		m_MotionFunc = MOTION_SIN;
 		m_Motion.clear();
 
@@ -674,7 +712,12 @@ public:
 	}
 
 //Why are we not using template with member var addr as arg here?//TODO
-#define APPMOT(x)  do { x += mot[i].x * Interpolater<T>::MotionFuncs(func, freq * blend); } while (0)
+#define APPMOT(x) \
+	do \
+	{ \
+		if (currentMot.x != EMPTYFIELD) \
+			x += currentMot.x * Interpolater<T>::MotionFuncs(func, freq * blend); \
+	} while (0)
 
 	/// <summary>
 	/// Apply the motion functions from the passed in xform to this xform.
@@ -683,15 +726,13 @@ public:
 	/// <param name="blend">The time blending value 0-1</param>
 	void ApplyMotion(Xform<T>& xform, T blend)
 	{
-		Xform<T>* mot = xform.m_Motion.data();
-
 		//Loop over the motion elements and add their contribution to the original vals.
 		for (size_t i = 0; i < xform.m_Motion.size(); i++)
 		{
 			//Original only pulls these from the first motion xform which is a bug. Want to pull it from each one.
-			Xform<T>* currentMot = &xform.m_Motion[i];
-			intmax_t freq = currentMot->m_MotionFreq;
-			eMotion func = currentMot->m_MotionFunc;
+			Xform<T>& currentMot = xform.m_Motion[i];
+			intmax_t freq = currentMot.m_MotionFreq;
+			eMotion func = currentMot.m_MotionFunc;
 
 			//Clamp these to the appropriate range after all are applied.
 			APPMOT(m_Weight);
@@ -702,9 +743,9 @@ public:
 			APPMOT(m_ColorSpeed);
 			APPMOT(m_Animate);
 
-			for (size_t j = 0; j < currentMot->TotalVariationCount(); j++)//For each variation in the motion xform.
+			for (size_t j = 0; j < currentMot.TotalVariationCount(); j++)//For each variation in the motion xform.
 			{
-				Variation<T>* motVar = currentMot->GetVariation(j);//Get the variation, which may or may not be present in this xform.
+				Variation<T>* motVar = currentMot.GetVariation(j);//Get the variation, which may or may not be present in this xform.
 				ParametricVariation<T>* motParVar = dynamic_cast<ParametricVariation<T>*>(motVar);
 
 				Variation<T>* var = GetVariationById(motVar->VariationId());//See if the variation in the motion xform was present in the xform.
@@ -752,7 +793,7 @@ public:
 		//ClampRef<T>(m_ColorY, 0, 1);
 		ClampRef<T>(m_DirectColor, 0, 1);
 		ClampRef<T>(m_Opacity, 0, 1);//Original didn't clamp these, but do it here for correctness.
-		ClampRef<T>(m_ColorSpeed, 0, 1);
+		ClampRef<T>(m_ColorSpeed, -1, 1);
 		ClampGte0Ref<T>(m_Weight);
 	}
 
diff --git a/Source/Ember/XmlToEmber.h b/Source/Ember/XmlToEmber.h
index 88785c8..93ebbaa 100644
--- a/Source/Ember/XmlToEmber.h
+++ b/Source/Ember/XmlToEmber.h
@@ -1018,7 +1018,7 @@ private:
 					{
 						if (!Compare(motionNode->name, "motion"))
 						{
-							Xform<T> xform;
+							Xform<T> xform(false);//Will only have valid values in fields parsed for motion, all others will be EMPTYFIELD.
 
 							if (!ParseXform(motionNode, xform, true))
 								m_ErrorReport.push_back(string(loc) + " : Error parsing motion xform");
diff --git a/Source/EmberTester/EmberTester.cpp b/Source/EmberTester/EmberTester.cpp
index 481604a..8d77a51 100644
--- a/Source/EmberTester/EmberTester.cpp
+++ b/Source/EmberTester/EmberTester.cpp
@@ -1956,12 +1956,12 @@ int _tmain(int argc, _TCHAR* argv[])
 	//std::complex<double> cd, cd2;
 
 	//cd2 = sin(cd);
-	/*
+	
 	t.Tic();
 	TestCasting();
 	t.Toc("TestCasting()");
 	
-	t.Tic();
+	/*t.Tic();
 	VariationList<float> vlf;
 	t.Toc("Creating VariationList<float>");