Restore 4x4 matrix functionn param and assignment prior to change in commit 168ae22 of 27 Oct 2019 (#5813)

Co-authored-by: Steve M <[email protected]>

code/AssetLib/FBX/FBXConverter.cpp

@@ -247,7 +247,7 @@ struct FBXConverter::PotentialNode {
 /// todo: get bone from stack
 /// todo: make map of aiBone* to aiNode*
 /// then update convert clusters to the new format
-void FBXConverter::ConvertNodes(uint64_t id, aiNode *parent, aiNode *root_node) {
+void FBXConverter::ConvertNodes(uint64_t id, aiNode *parent, aiNode *root_node, const aiMatrix4x4& parent_transform) {
     const std::vector<const Connection *> &conns = doc.GetConnectionsByDestinationSequenced(id, "Model");
 
     std::vector<PotentialNode> nodes;
@@ -278,7 +278,7 @@ void FBXConverter::ConvertNodes(uint64_t id, aiNode *parent, aiNode *root_node)
         if (nullptr != model) {
             nodes_chain.clear();
             post_nodes_chain.clear();
-            aiMatrix4x4 new_abs_transform = parent->mTransformation;
+            aiMatrix4x4 new_abs_transform = parent_transform;
             std::string node_name = FixNodeName(model->Name());
             // even though there is only a single input node, the design of
             // assimp (or rather: the complicated transformation chain that
@@ -345,7 +345,7 @@ void FBXConverter::ConvertNodes(uint64_t id, aiNode *parent, aiNode *root_node)
             }
 
             // recursion call - child nodes
-            ConvertNodes(model->ID(), last_parent, root_node);
+            ConvertNodes(model->ID(), last_parent, root_node, new_abs_transform);
 
             if (doc.Settings().readLights) {
                 ConvertLights(*model, node_name);
@@ -1676,14 +1676,14 @@ void FBXConverter::ConvertCluster(std::vector<aiBone*> &local_mesh_bones, const
 
         //bone->mOffsetMatrix = cluster->Transform();
         // store local transform link for post processing
-        
+
         bone->mOffsetMatrix = cluster->TransformLink();
         bone->mOffsetMatrix.Inverse();
 
         const aiMatrix4x4 matrix = (aiMatrix4x4)absolute_transform;
 
         bone->mOffsetMatrix = bone->mOffsetMatrix * matrix; // * mesh_offset
-        
+
         //
         // Now calculate the aiVertexWeights
         //

code/AssetLib/FBX/FBXConverter.h

@@ -134,7 +134,7 @@ private:
 
     // ------------------------------------------------------------------------------------------------
     // collect and assign child nodes
-    void ConvertNodes(uint64_t id, aiNode *parent, aiNode *root_node);
+    void ConvertNodes(uint64_t id, aiNode *parent, aiNode *root_node, const aiMatrix4x4& parent_transform = aiMatrix4x4());
 
     // ------------------------------------------------------------------------------------------------
     void ConvertLights(const Model& model, const std::string &orig_name );