diff --git a/include/Nazara/Math/Matrix4.hpp b/include/Nazara/Math/Matrix4.hpp
index 08265e983..89aeec65e 100644
--- a/include/Nazara/Math/Matrix4.hpp
+++ b/include/Nazara/Math/Matrix4.hpp
@@ -53,6 +53,7 @@ class NzMatrix4
 		NzMatrix4& InverseAffine(bool* succeeded = nullptr);
 
 		bool IsAffine() const;
+		bool IsIdentity() const;
 
 		NzMatrix4& MakeIdentity();
 		NzMatrix4& MakeLookAt(const NzVector3<T>& eye, const NzVector3<T>& target, const NzVector3<T>& up = NzVector3<T>::Up());
@@ -117,10 +118,12 @@ class NzMatrix4
 		static NzMatrix4 Transform(const NzVector3<T>& translation, const NzQuaternion<T>& rotation, const NzVector3<T>& scale);
 		static NzMatrix4 Zero();
 
-		T m11, m12, m13, m14,
-		  m21, m22, m23, m24,
-		  m31, m32, m33, m34,
-		  m41, m42, m43, m44;
+		private:
+			T m11, m12, m13, m14,
+			  m21, m22, m23, m24,
+			  m31, m32, m33, m34,
+			  m41, m42, m43, m44;
+			mutable bool m_isIdentity;
 };
 
 template<typename T> std::ostream& operator<<(std::ostream& out, const NzMatrix4<T>& matrix);
diff --git a/include/Nazara/Math/Matrix4.inl b/include/Nazara/Math/Matrix4.inl
index bcf71684b..e8a54c811 100644
--- a/include/Nazara/Math/Matrix4.inl
+++ b/include/Nazara/Math/Matrix4.inl
@@ -57,6 +57,7 @@ NzMatrix4<T>& NzMatrix4<T>::ApplyScale(const NzVector3<T>& scale)
 	m31 *= scale.z;
 	m32 *= scale.z;
 	m33 *= scale.z;
+	m_isIdentity = false;
 
 	return *this;
 }
@@ -69,6 +70,9 @@ NzMatrix4<T>& NzMatrix4<T>::Concatenate(const NzMatrix4& matrix)
 		return ConcatenateAffine(matrix);
 	#endif
 
+	if (m_isIdentity)
+		return Set(matrix);
+
 	return Set(m11*matrix.m11 + m12*matrix.m21 + m13*matrix.m31 + m14*matrix.m41,
 	           m11*matrix.m12 + m12*matrix.m22 + m13*matrix.m32 + m14*matrix.m42,
 	           m11*matrix.m13 + m12*matrix.m23 + m13*matrix.m33 + m14*matrix.m43,
@@ -107,6 +111,9 @@ NzMatrix4<T>& NzMatrix4<T>::ConcatenateAffine(const NzMatrix4& matrix)
 	}
 	#endif
 
+	if (m_isIdentity)
+		return Set(matrix);
+
 	return Set(m11*matrix.m11 + m12*matrix.m21 + m13*matrix.m31,
 	           m11*matrix.m12 + m12*matrix.m22 + m13*matrix.m32,
 	           m11*matrix.m13 + m12*matrix.m23 + m13*matrix.m33,
@@ -131,6 +138,9 @@ NzMatrix4<T>& NzMatrix4<T>::ConcatenateAffine(const NzMatrix4& matrix)
 template<typename T>
 T NzMatrix4<T>::GetDeterminant() const
 {
+	if (m_isIdentity)
+		return F(1.0);
+
 	T A = m22*(m33*m44 - m43*m34) - m32*(m23*m44 - m43*m24) + m42*(m23*m34 - m33*m24);
 	T B = m12*(m33*m44 - m43*m34) - m32*(m13*m44 - m43*m14) + m42*(m13*m34 - m33*m14);
 	T C = m12*(m23*m44 - m43*m24) - m22*(m13*m44 - m43*m14) + m42*(m13*m24 - m23*m14);
@@ -142,6 +152,9 @@ T NzMatrix4<T>::GetDeterminant() const
 template<typename T>
 T NzMatrix4<T>::GetDeterminantAffine() const
 {
+	if (m_isIdentity)
+		return F(1.0);
+
 	T A = m22*m33 - m32*m23;
 	T B = m12*m33 - m32*m13;
 	T C = m12*m23 - m22*m13;
@@ -161,6 +174,12 @@ bool NzMatrix4<T>::GetInverse(NzMatrix4* dest) const
 	}
 	#endif
 
+	if (m_isIdentity)
+	{
+		dest->MakeIdentity();
+		return true;
+	}
+
 	T det = GetDeterminant();
 	if (!NzNumberEquals(det, F(0.0)))
 	{
@@ -310,6 +329,12 @@ bool NzMatrix4<T>::GetInverseAffine(NzMatrix4* dest) const
 	}
 	#endif
 
+	if (m_isIdentity)
+	{
+		dest->MakeIdentity();
+		return true;
+	}
+
 	T det = GetDeterminantAffine();
 	if (!NzNumberEquals(det, F(0.0)))
 	{
@@ -388,6 +413,9 @@ bool NzMatrix4<T>::GetInverseAffine(NzMatrix4* dest) const
 template<typename T>
 NzQuaternion<T> NzMatrix4<T>::GetRotation() const
 {
+	if (m_isIdentity)
+		return NzQuaternion<T>::Identity();
+
 	// http://www.euclideanspace.com/maths/geometry/rotations/conversions/matrixToQuaternion/
 	NzQuaternion<T> quat;
 
@@ -437,6 +465,9 @@ NzQuaternion<T> NzMatrix4<T>::GetRotation() const
 template<typename T>
 NzVector3<T> NzMatrix4<T>::GetScale() const
 {
+	if (m_isIdentity)
+		return NzVector3<T>::Unit();
+
 	return NzVector3<T>(std::sqrt(m11*m11 + m21*m21 + m31*m31),
 						std::sqrt(m12*m12 + m22*m22 + m32*m32),
 						std::sqrt(m13*m13 + m23*m23 + m33*m33));
@@ -455,17 +486,25 @@ void NzMatrix4<T>::GetTransposed(NzMatrix4* dest) const
 	          m12, m22, m32, m42,
 	          m13, m23, m33, m43,
 	          m14, m24, m34, m44);
+
+	dest->m_isIdentity = m_isIdentity;
 }
 
 template<typename T>
 bool NzMatrix4<T>::HasNegativeScale() const
 {
+	if (m_isIdentity)
+		return false;
+
 	return GetDeterminant() < F(0.0);
 }
 
 template<typename T>
 bool NzMatrix4<T>::HasScale() const
 {
+	if (m_isIdentity)
+		return false;
+
 	T t = m11*m11 + m21*m21 + m31*m31;
 	if (!NzNumberEquals(t, F(1.0)))
 		return true;
@@ -510,6 +549,24 @@ bool NzMatrix4<T>::IsAffine() const
 	       NzNumberEquals(m44, F(1.0));
 }
 
+template<typename T>
+bool NzMatrix4<T>::IsIdentity() const
+{
+	if (m_isIdentity)
+		return true;
+
+	if (NzNumberEquals(m11, F(1.0)) && NzNumberEquals(m12, F(0.0)) && NzNumberEquals(m13, F(0.0)) && NzNumberEquals(m14, F(0.0)) &&
+	    NzNumberEquals(m11, F(0.0)) && NzNumberEquals(m12, F(1.0)) && NzNumberEquals(m13, F(0.0)) && NzNumberEquals(m14, F(0.0)) &&
+	    NzNumberEquals(m11, F(0.0)) && NzNumberEquals(m12, F(0.0)) && NzNumberEquals(m13, F(1.0)) && NzNumberEquals(m14, F(0.0)) &&
+	    NzNumberEquals(m11, F(0.0)) && NzNumberEquals(m12, F(0.0)) && NzNumberEquals(m13, F(0.0)) && NzNumberEquals(m14, F(1.0)))
+	{
+		m_isIdentity = true;
+		return true;
+	}
+
+	return false;
+}
+
 template<typename T>
 NzMatrix4<T>& NzMatrix4<T>::MakeIdentity()
 {
@@ -518,6 +575,8 @@ NzMatrix4<T>& NzMatrix4<T>::MakeIdentity()
 		F(0.0), F(0.0), F(1.0), F(0.0),
 		F(0.0), F(0.0), F(0.0), F(1.0));
 
+	m_isIdentity = true;
+
 	return *this;
 }
 
@@ -582,6 +641,7 @@ NzMatrix4<T>& NzMatrix4<T>::MakeRotation(const NzQuaternion<T>& rotation)
 	m42 = F(0.0);
 	m43 = F(0.0);
 	m44 = F(1.0);
+	m_isIdentity = false;
 
 	return *this;
 }
@@ -621,6 +681,8 @@ NzMatrix4<T>& NzMatrix4<T>::MakeTransform(const NzVector3<T>& translation, const
 	m34 = F(0.0);
 	m44 = F(1.0);
 
+	// Pas besoin de mettre à jour l'identité (Déjà fait par Set*)
+
 	return *this;
 }
 
@@ -668,6 +730,7 @@ NzMatrix4<T>& NzMatrix4<T>::Set(T r11, T r12, T r13, T r14,
 	m42 = r42;
 	m43 = r43;
 	m44 = r44;
+	m_isIdentity = false;
 
 	return *this;
 }
@@ -677,6 +740,7 @@ NzMatrix4<T>& NzMatrix4<T>::Set(const T matrix[16])
 {
 	// Ici nous sommes certains de la continuité des éléments en mémoire
 	std::memcpy(&m11, matrix, 16*sizeof(T));
+	m_isIdentity = false;
 
 	return *this;
 }
@@ -698,6 +762,8 @@ NzMatrix4<T>& NzMatrix4<T>::Set(const NzMatrix4<U>& matrix)
 		F(matrix.m31), F(matrix.m32), F(matrix.m33), F(matrix.m34),
 		F(matrix.m41), F(matrix.m42), F(matrix.m43), F(matrix.m44));
 
+	m_isIdentity = matrix.IsIdentity();
+
 	return *this;
 }
 
@@ -728,6 +794,7 @@ NzMatrix4<T>& NzMatrix4<T>::SetRotation(const NzQuaternion<T>& rotation)
 	m31 = txz + twy;
 	m32 = tyz - twx;
 	m33 = F(1.0) - (txx + tyy);
+	m_isIdentity = false;
 
 	return *this;
 }
@@ -738,6 +805,7 @@ NzMatrix4<T>& NzMatrix4<T>::SetScale(const NzVector3<T>& scale)
 	m11 = scale.x;
 	m22 = scale.y;
 	m33 = scale.z;
+	m_isIdentity = false;
 
 	return *this;
 }
@@ -748,6 +816,7 @@ NzMatrix4<T>& NzMatrix4<T>::SetTranslation(const NzVector3<T>& translation)
 	m41 = translation.x;
 	m42 = translation.y;
 	m43 = translation.z;
+	m_isIdentity = false;
 
 	return *this;
 }
@@ -765,6 +834,9 @@ NzString NzMatrix4<T>::ToString() const
 template<typename T>
 NzVector2<T> NzMatrix4<T>::Transform(const NzVector2<T>& vector, T z, T w) const
 {
+	if (m_isIdentity)
+		return vector;
+
 	return NzVector2<T>(m11*vector.x + m21*vector.y + m31*z + m41*w,
 	                    m12*vector.x + m22*vector.y + m32*z + m42*w);
 }
@@ -772,6 +844,9 @@ NzVector2<T> NzMatrix4<T>::Transform(const NzVector2<T>& vector, T z, T w) const
 template<typename T>
 NzVector3<T> NzMatrix4<T>::Transform(const NzVector3<T>& vector, T w) const
 {
+	if (m_isIdentity)
+		return vector;
+
 	return NzVector3<T>(m11*vector.x + m21*vector.y + m31*vector.z + m41*w,
 	                    m12*vector.x + m22*vector.y + m32*vector.z + m42*w,
 	                    m13*vector.x + m23*vector.y + m33*vector.z + m43*w);
@@ -780,6 +855,9 @@ NzVector3<T> NzMatrix4<T>::Transform(const NzVector3<T>& vector, T w) const
 template<typename T>
 NzVector4<T> NzMatrix4<T>::Transform(const NzVector4<T>& vector) const
 {
+	if (m_isIdentity)
+		return vector;
+
 	return NzVector4<T>(m11*vector.x + m21*vector.y + m31*vector.z + m41*vector.w,
 	                    m12*vector.x + m22*vector.y + m32*vector.z + m42*vector.w,
 	                    m13*vector.x + m23*vector.y + m33*vector.z + m43*vector.w,
@@ -802,6 +880,7 @@ NzMatrix4<T>& NzMatrix4<T>::Transpose()
 template<typename T>
 NzMatrix4<T>::operator T*()
 {
+	m_isIdentity = false;
 	return &m11;
 }
 
@@ -824,6 +903,7 @@ T& NzMatrix4<T>::operator()(unsigned int x, unsigned int y)
 	}
 	#endif
 
+	m_isIdentity = false;
 	return (&m11)[y*4+x];
 }
 
@@ -890,6 +970,7 @@ NzMatrix4<T>& NzMatrix4<T>::operator*=(const NzMatrix4& matrix)
 template<typename T>
 NzMatrix4<T>& NzMatrix4<T>::operator*=(T scalar)
 {
+	m_isIdentity = false;
 	for (unsigned int i = 0; i < 16; ++i)
 		(&m11)[i] *= scalar;