From a73397198c4c8d5ef0debe792ecff5d06646a038 Mon Sep 17 00:00:00 2001
From: ulfjorensen <ulfjorensen@67173fc5-114c-0410-ac8e-9d2fd5bffc1f>
Date: Mon, 12 Dec 2011 08:44:48 +0000
Subject: [PATCH] - Bugfix #3457587: correct decomposition of matrices with
 negative scaling. Thanks to anonymous google account user for the fix.

git-svn-id: https://assimp.svn.sourceforge.net/svnroot/assimp/trunk@1099 67173fc5-114c-0410-ac8e-9d2fd5bffc1f
---
 code/ColladaLoader.cpp  | 3 ++-
 include/aiMatrix4x4.inl | 7 +++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/code/ColladaLoader.cpp b/code/ColladaLoader.cpp
index 6b4870ac8..e5f4d983a 100644
--- a/code/ColladaLoader.cpp
+++ b/code/ColladaLoader.cpp
@@ -1084,8 +1084,9 @@ void ColladaLoader::CreateAnimation( aiScene* pScene, const ColladaParser& pPars
 
 		for( size_t a = 0; a < resultTrafos.size(); ++a)
 		{
-			const aiMatrix4x4& mat = resultTrafos[a];
+			aiMatrix4x4 mat = resultTrafos[a];
 			double time = double( mat.d4); // remember? time is stored in mat.d4
+      mat.d4 = 1.0f;
 
 			dstAnim->mPositionKeys[a].mTime = time;
 			dstAnim->mRotationKeys[a].mTime = time;
diff --git a/include/aiMatrix4x4.inl b/include/aiMatrix4x4.inl
index fa37dd4e2..a922c4afe 100644
--- a/include/aiMatrix4x4.inl
+++ b/include/aiMatrix4x4.inl
@@ -217,6 +217,13 @@ inline void aiMatrix4x4::Decompose (aiVector3D& scaling, aiQuaternion& rotation,
 	scaling.y = vRows[1].Length();
 	scaling.z = vRows[2].Length();
 
+	// and the sign of the scaling
+	if (Determinant() < 0) {
+		scaling.x = -scaling.x;
+		scaling.y = -scaling.y;
+		scaling.z = -scaling.z;
+	}
+
 	// and remove all scaling from the matrix
 	if(scaling.x)
 	{