Handle tangent calculation errors along weird niche points better.

Author: Lunaretic

xivModdingFramework/Models/DataContainers/TTModel.cs

@@ -124,7 +124,12 @@ public int GetWeldHash()
         public Vector3 GetTangentSpaceFlow()
         {
             var flow = WorldToTangent(FlowDirection.ToArray());
-            return new Vector3(flow[0], flow[1], 0).Normalized();
+            var ret = new Vector3(flow[0], flow[1], 0).Normalized();
+            if(float.IsNaN(ret.X) || float.IsNaN(ret.Y) || float.IsNaN(ret.Z))
+            {
+                return Vector3.Zero;
+            }
+            return ret;
         }
 
         public float[] WorldToTangent(float[] vector)
@@ -201,6 +206,7 @@ public static List<TTVertex> CloneVertexList(List<TTVertex> verts)
             if (a.Position != b.Position) return false;
             if (a.Normal != b.Normal) return false;
             if (a.Binormal != b.Binormal) return false;
+            if (a.Tangent != b.Tangent) return false;
             if (a.Handedness != b.Handedness) return false;
             if (a.FlowDirection != b.FlowDirection) return false;
             if (a.UV1 != b.UV1) return false;

xivModdingFramework/Models/Helpers/ModelModifiers.cs

@@ -2082,6 +2082,11 @@ private static void CalculateTangentsForMesh(TTMeshGroup m, bool force = false)
                 var deltaV2 = v3uv.Y - v1uv.Y;
 
                 var r = 1.0f / (deltaU1 * deltaV2 - deltaU2 * deltaV1);
+                if(float.IsInfinity(r))
+                {
+                    r = 0;
+                }
+
                 var sdir = new Vector3((deltaV2 * deltaX1 - deltaV1 * deltaX2) * r, (deltaV2 * deltaY1 - deltaV1 * deltaY2) * r, (deltaV2 * deltaZ1 - deltaV1 * deltaZ2) * r);
                 var tdir = new Vector3((deltaU1 * deltaX2 - deltaU2 * deltaX1) * r, (deltaU1 * deltaY2 - deltaU2 * deltaY1) * r, (deltaU1 * deltaZ2 - deltaU2 * deltaZ1) * r);
 
@@ -2092,7 +2097,7 @@ private static void CalculateTangentsForMesh(TTMeshGroup m, bool force = false)
                 bitangents[vertexId1] += tdir;
                 bitangents[vertexId2] += tdir;
                 bitangents[vertexId3] += tdir;
-                }
+            }