FBX: Fix for loading taking a very long time on models with many duplicate names (issue_2390)

code/FBXConverter.cpp

@@ -410,16 +410,17 @@ namespace Assimp {
 
         void FBXConverter::GetUniqueName(const std::string &name, std::string &uniqueName)
         {
-            int i = 0;
             uniqueName = name;
-            while (mNodeNames.find(uniqueName) != mNodeNames.end())
+            int i = 0;
+            auto it = mNodeNameInstances.find(uniqueName);
+            if (it != mNodeNameInstances.end())
             {
-                ++i;
+                i = it->second + 1;
                 std::stringstream ext;
                 ext << name << std::setfill('0') << std::setw(3) << i;
                 uniqueName = ext.str();
             }
-            mNodeNames.insert(uniqueName);
+            mNodeNameInstances[name] = i;
         }
 
 

code/FBXConverter.h

@@ -58,6 +58,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <assimp/texture.h>
 #include <assimp/camera.h>
 #include <assimp/StringComparison.h>
+#include <unordered_map>
 
 struct aiScene;
 struct aiNode;
@@ -74,8 +75,6 @@ namespace FBX {
 
 class Document;
 
-using NodeNameCache = std::set<std::string>;
-
 /** 
  *  Convert a FBX #Document to #aiScene
  *  @param out Empty scene to be populated
@@ -444,7 +443,10 @@ private:
     typedef std::map<std::string, unsigned int> NodeAnimBitMap;
     NodeAnimBitMap node_anim_chain_bits;
 
-    NodeNameCache mNodeNames;
+    // number of nodes with the same name
+    typedef std::unordered_map<std::string, unsigned int> NodeNameMap;
+    NodeNameMap mNodeNameInstances;
+
     double anim_fps;
 
     aiScene* const out;