Refactored code to be better separated (Rendering, Logic)

Scripts/Helpers/DecorationHandler.cs

@@ -0,0 +1,48 @@
+using Godot;
+using System.Collections.Generic;
+
+public class DecorationHandler
+{
+    public static void Spawn(List<TileRenderData> tiles, Dictionary<string, MeshInstance3D> decorationMeshes)
+    {
+        foreach (var data in tiles)
+        {
+            Node3D tileNode = data.Tile.DecorationNode;
+
+            foreach (var placeholder in data.Placeholders)
+            {
+                string key = placeholder.name.ToLower();
+
+                var decoration = new MeshInstance3D();
+
+                if (decorationMeshes.ContainsKey(key))
+                {
+                    decoration.Mesh = decorationMeshes[key].Mesh;
+                }
+                else
+                {
+                    continue;
+                }
+
+                decoration.Position = placeholder.pos;
+
+                decoration.Rotate(Vector3.Up, Mathf.DegToRad(-90));
+
+                if (key == "light")
+                {
+                    decoration.AddChild(new OmniLight3D()
+                    {
+                        OmniAttenuation = 2f,
+                        LightColor = new Color("#eae7ad"),
+                        ShadowEnabled = true,
+                        LightEnergy = 5f,
+                        LightIndirectEnergy = 1.5f,
+                        Position = new Vector3(0.5f, 0, 0)
+                    });
+                }
+
+                tileNode.AddChild(decoration);
+            }
+        }
+    }
+}

Scripts/Helpers/DecorationHandler.cs.uid

@@ -0,0 +1 @@
+uid://oe2d2ape41jj

Scripts/Helpers/Layer.cs

@@ -5,6 +5,7 @@ using System.Linq;
 using static WFC;
 public partial class Layer : Node3D
 {
+	private Node3D decorationRoot;
 	public Tile[,] tiles;
 	int layerSize;
 	Tile tile;
@@ -14,7 +15,11 @@ public partial class Layer : Node3D
 	// Called when the node enters the scene tree for the first time.
 	public override void _Ready()
 	{
-
+		decorationRoot = new Node3D
+		{
+			Name = "Decorations"
+		};
+		AddChild(decorationRoot);
 	}
 
 	// Called every frame. 'delta' is the elapsed time since the previous frame.
@@ -22,6 +27,17 @@ public partial class Layer : Node3D
 	{
 	}
 
+	public void ClearDecorations()
+	{
+		foreach (var tile in tiles)
+		{
+			foreach (Node child in tile.DecorationNode.GetChildren())
+			{
+				child.QueueFree();
+			}
+		}
+	}
+
 	public void SetupLayer(int layerSize, int level, Dictionary<string, MeshInstance3D> tileMeshes)
 	{
 		this.layerSize = layerSize;
@@ -44,6 +60,7 @@ public partial class Layer : Node3D
 			safetyCounter++;
 			if (safetyCounter > 1000) break;
 		}
+		CreateTileNodes();
 	}
 
 	private void GenerateBaseStructure(Dictionary<string, MeshInstance3D> tileMeshes)
@@ -68,6 +85,20 @@ public partial class Layer : Node3D
 		}
 	}
 
+	private void CreateTileNodes()
+	{
+		foreach (var tile in tiles)
+		{
+            var node = new Node3D
+            {
+                Position = tile.Position
+            };
+            decorationRoot.AddChild(node);
+
+			tile.DecorationNode = node;
+		}
+	}
+
 	private void ResetLayer(Dictionary<string, MeshInstance3D> tileMeshes)
 	{
 		for (int x = 0; x < layerSize; x++)

Scripts/Helpers/MultimeshHandler.cs

@@ -0,0 +1,39 @@
+using Godot;
+using System.Collections.Generic;
+
+public class MultiMeshHandler
+{
+    private Dictionary<string, MultiMeshInstance3D> multiMeshes;
+
+    public MultiMeshHandler(Dictionary<string, MultiMeshInstance3D> multiMeshes)
+    {
+        this.multiMeshes = multiMeshes;
+    }
+
+    public void Build(List<TileRenderData> tiles)
+    {
+        foreach (var mm in multiMeshes.Values)
+            mm.Multimesh.InstanceCount = 0;
+
+        var batches = new Dictionary<string, List<Transform3D>>();
+
+        foreach (var tile in tiles)
+        {
+            if (!batches.ContainsKey(tile.MeshKey))
+                batches[tile.MeshKey] = new List<Transform3D>();
+
+            batches[tile.MeshKey].Add(tile.Transform);
+        }
+
+        foreach (var kvp in batches)
+        {
+            var mm = multiMeshes[kvp.Key].Multimesh;
+            var list = kvp.Value;
+
+            mm.InstanceCount = list.Count;
+
+            for (int i = 0; i < list.Count; i++)
+                mm.SetInstanceTransform(i, list[i]);
+        }
+    }
+}

Scripts/Helpers/MultimeshHandler.cs.uid

@@ -0,0 +1 @@
+uid://dc0v2yndgikkw