Use instancing for HexTile3D rendering.

scenes/Game.tscn

@@ -70,7 +70,6 @@ align = 2
 anims/FlashLabel = SubResource( 25 )
 
 [node name="DebugContainer" type="PanelContainer" parent="."]
-visible = false
 self_modulate = Color( 1, 1, 1, 0.443137 )
 anchor_left = 1.0
 anchor_top = 1.0

scenes/HexTile3D.tscn

@@ -23,6 +23,7 @@ script = ExtResource( 1 )
 
 [node name="Mesh" type="MeshInstance" parent="." groups=["GameGeometry"]]
 transform = Transform( -4.37114e-08, 0, 1, 0, 1, 0, -1, 0, -4.37114e-08, 0, -2.5, 0 )
+visible = false
 mesh = ExtResource( 3 )
 material/0 = ExtResource( 2 )
 

scenes/StreamContainer.cs

@@ -7,11 +7,15 @@ using GoDotLog;
 
 public class StreamContainer : Spatial
 {
+    // readonly variables
+    private readonly Transform _deactivatedTileTransform = new Transform(Basis.Identity, Vector3.Up * 1000);
+    
     // scene nodes
     private MeshInstance _bounds;
     private Spatial _activeTiles;
     private Queue<HexTile3D> _unusedTiles;
     private TileWorld _tileWorld;
+    private MultiMeshInstance _tileMultiMesh;
 
     // resources
     private PackedScene _hexTileScene = GD.Load<PackedScene>("res://scenes/HexTile3D.tscn");
@@ -27,12 +31,12 @@ public class StreamContainer : Spatial
     delegate void TileHovered(HexTile3D tile3d);
 
     // other members
-    private Rect2 _worldRect;
     private Rect2 _currentOffsetCoordRect;
     private Rect2 _oldOffsetCoordRect;
     private HexGrid _hexGrid;
 
-    private Dictionary<Vector2, HexTile3D> _coordToTile = new Dictionary<Vector2, HexTile3D>();
+    private Dictionary<Vector2, HexTile3D> _coordToTile = new();
+    private Dictionary<HexTile3D, int> _tileToInstanceIndex = new();
     public List<Vector2> RemovedCoords = new List<Vector2>();
     public List<Vector2> AddedCoords = new List<Vector2>();
 
@@ -52,6 +56,14 @@ public class StreamContainer : Spatial
         _unusedTiles = new Queue<HexTile3D>();
         _bounds = GetNode<MeshInstance>("Bounds");
         _activeTiles = GetNode<Spatial>("ActiveTiles");
+        
+        _tileMultiMesh = GetNode<MultiMeshInstance>("TileMultiMesh");
+        _tileMultiMesh.Multimesh.InstanceCount = (int)((Dimensions.x + 5) * (Dimensions.y + 5));
+        _tileMultiMesh.Multimesh.InstanceCount = 1810;
+        foreach (int i in Enumerable.Range(0, _tileMultiMesh.Multimesh.InstanceCount))
+        {
+            _tileMultiMesh.Multimesh.SetInstanceTransform(i, _deactivatedTileTransform);
+        }
 
         _hexGrid = new HexGrid();
 
@@ -69,8 +81,7 @@ public class StreamContainer : Spatial
 
         Vector2 bottomLeftCoord = centerPlane - new Vector2(Dimensions.x / 2, Dimensions.y / 2);
         Vector2 topRightCoord = centerPlane + new Vector2(Dimensions.x / 2, Dimensions.y / 2);
-
+        
-        _worldRect = new Rect2(bottomLeftCoord, Dimensions);
 //        GD.Print("World rect now: " + _worldRect.ToString() + " center: " + _worldRect.GetCenter());
 
         // y axis needs to be inverted as HexGrid's offset coordinates use the opposite axis direction
@@ -78,6 +89,10 @@ public class StreamContainer : Spatial
         HexCell topRightCell = _hexGrid.GetHexAt(new Vector2(topRightCoord.x, bottomLeftCoord.y));
         _currentOffsetCoordRect = new Rect2(bottomLeftCell.OffsetCoords,
             topRightCell.OffsetCoords - bottomLeftCell.OffsetCoords + Vector2.One);
+
+//        Vector2 centerOffset = _hexGrid.GetHexAt(centerPlane).OffsetCoords;
+//        _currentOffsetCoordRect = new Rect2(centerOffset + new Vector2(-Dimensions.x / 2, -Dimensions.y / 2),
+//            Dimensions);
 //        GD.Print("Offset rect now: " + _currentOffsetCoordRect.ToString() + " center: " +
 //                 _currentOffsetCoordRect.GetCenter());
 
@@ -140,10 +155,8 @@ public class StreamContainer : Spatial
                 if (isInOld && !isInCurrent && _coordToTile.Keys.Contains(coord))
                 {
                     HexTile3D tile3D = _coordToTile[coord];
-                    tile3D.Type = HexTile3D.TileType.Undefined;
+                    
-                    _unusedTiles.Enqueue(tile3D);
+                    OnTileDeactivate(tile3D, coord);
-                    _coordToTile.Remove(coord);
-                    RemovedCoords.Add(coord);
                 }
             }
         }
@@ -178,6 +191,8 @@ public class StreamContainer : Spatial
                     tileTransform.origin.y = _tileWorld.GetHeightAtOffset(coord);
                     tile3D.Transform = tileTransform;
                     
+                    OnTileActivate(tile3D);
+                    
                     _coordToTile[coord] = tile3D;
                 }
             }
@@ -205,10 +220,14 @@ public class StreamContainer : Spatial
             tileTransform.origin.y = _tileWorld.GetHeightAtOffset(offsetCoords);
             tile3D.Transform = tileTransform;
             tile3D.Type = _tileWorld.GetTileTypeAtOffset(offsetCoords);
+
+            _tileToInstanceIndex[tile3D] = _tileToInstanceIndex.Count;
             
             _coordToTile[offsetCoords] = tile3D;
         }
 
+        OnTileActivate(_coordToTile[offsetCoords]);
+        
         return _coordToTile[offsetCoords];
     }
 
@@ -231,6 +250,26 @@ public class StreamContainer : Spatial
         }
     }
 
+    public void OnTileActivate(HexTile3D tile3D)
+    {
+        int instanceIndex = _tileToInstanceIndex[tile3D];
+
+        Transform instanceTransform = new Transform(tile3D.GlobalTransform.basis.Rotated(Vector3.Up, Mathf.Deg2Rad(30)), tile3D.GlobalTransform.origin + Vector3.Up * -2.5f);
+        
+        _tileMultiMesh.Multimesh.SetInstanceTransform(instanceIndex, instanceTransform);
+    }
+
+    public void OnTileDeactivate(HexTile3D tile3D, Vector2 coord)
+    {
+        int instanceIndex = _tileToInstanceIndex[tile3D];
+        _tileMultiMesh.Multimesh.SetInstanceTransform(instanceIndex, _deactivatedTileTransform);
+        
+        tile3D.Type = HexTile3D.TileType.Undefined;
+        _unusedTiles.Enqueue(tile3D);
+        _coordToTile.Remove(coord);
+        RemovedCoords.Add(coord);
+    }
+
     public void OnTileClicked(HexTile3D tile)
     {
         EmitSignal("TileClicked", tile);
@@ -254,6 +293,8 @@ public class StreamContainer : Spatial
             Transform tileTransform = tile.GlobalTransform;
             tileTransform.origin.y = _tileWorld.GetHeightAtOffset(tile.OffsetCoords);
             tile.GlobalTransform = tileTransform;
+            
+            OnTileActivate(tile);
         }
     }
 }

scenes/StreamContainer.tscn

@@ -1,6 +1,7 @@
-[gd_scene load_steps=5 format=2]
+[gd_scene load_steps=7 format=2]
 
 [ext_resource path="res://scenes/StreamContainer.cs" type="Script" id=1]
+[ext_resource path="res://assets/Environment/HexTileMesh.tres" type="CylinderMesh" id=2]
 
 [sub_resource type="CubeMesh" id=1]
 size = Vector3( 1, 1, 1 )
@@ -12,6 +13,11 @@ albedo_color = Color( 1, 1, 1, 0.156863 )
 [sub_resource type="BoxShape" id=9]
 extents = Vector3( 20, 1, 20 )
 
+[sub_resource type="MultiMesh" id=10]
+color_format = 2
+transform_format = 1
+mesh = ExtResource( 2 )
+
 [node name="StreamContainer" type="Spatial"]
 transform = Transform( 1, 0, 0, 0, 1, 2.98023e-08, 0, -2.98023e-08, 1, 0, 0, -4.76837e-07 )
 script = ExtResource( 1 )
@@ -32,3 +38,6 @@ material/0 = SubResource( 2 )
 [node name="CollisionShape" type="CollisionShape" parent="Area"]
 transform = Transform( 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, -1, 0 )
 shape = SubResource( 9 )
+
+[node name="TileMultiMesh" type="MultiMeshInstance" parent="."]
+multimesh = SubResource( 10 )