Moved creation of game objects for the world to GameState, which is where the bridge between Quake's game logic and Unity's game objects will happen. Also includes destruction of said game objects, so that the world is properly destroyed and recreated on map change.

Assets/Scripts/Game/GameAssets.cs

@@ -52,7 +52,7 @@ public class GameAssets
 
     public void SetWorldModel(BrushModel brushModel)
     {
-        worldModel?.Dispose();     // TODO: also need to clean up any GameObjects made from this
+        worldModel?.Dispose();
         worldModel = brushModel;
     }
 

Assets/Scripts/Game/GameState.cs

@@ -1,13 +1,67 @@
 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
+using UnityEngine.Rendering;
 
 public class GameState
 {
     private readonly UniQuake uq;
 
+    private GameObject worldGameObject;
+
     public GameState(UniQuake uniQuake)
     {
         uq = uniQuake;
     }
+
+    public void Destroy()
+    {
+        DestroyWorld();
+    }
+
+    public void NewMap(BrushModel worldModel)
+    {
+        DestroyWorld();
+        
+        // DEBUG - we'll want to instantiate prefabs for each submodel and assign materials from a preset collection
+        worldGameObject = new GameObject(worldModel.Name);
+        for (int i = 0; i < worldModel.SubModelCount; ++i)
+        {
+            var subModel = worldModel.GetSubModel(i);
+            var subModelGO = new GameObject($"SubModel_{i}");
+            subModelGO.transform.SetParent(worldGameObject.transform);
+            
+            foreach (var surfaceMesh in subModel.SurfaceMeshes)
+            {
+                var meshGO = new GameObject(surfaceMesh.Mesh.name);
+                meshGO.transform.SetParent(subModelGO.transform);
+
+                var mf = meshGO.AddComponent<MeshFilter>();
+                mf.sharedMesh = surfaceMesh.Mesh;
+
+                var material = new Material(Shader.Find("Universal Render Pipeline/Simple Lit"));
+                uint texNum = surfaceMesh.Texture.TextureNum;
+                if (uq.GameAssets.TryGetTexture(texNum, out var texture))
+                {
+                    material.mainTexture = texture;
+                }
+
+                var mr = meshGO.AddComponent<MeshRenderer>();
+                mr.sharedMaterial = material;
+                mr.shadowCastingMode = ShadowCastingMode.Off;
+                mr.receiveShadows = false;
+                mr.lightProbeUsage = LightProbeUsage.Off;
+                mr.reflectionProbeUsage = ReflectionProbeUsage.Off;
+            }
+        }
+    }
+
+    private void DestroyWorld()
+    {
+        if (worldGameObject != null)
+        {
+            Object.Destroy(worldGameObject);
+            worldGameObject = null;
+        }
+    }
 }

Assets/Scripts/Modules/RenderModule.cs

@@ -107,42 +107,11 @@ public partial class RenderModule
     {
         Debug.Log($"World model '{model.name}' with {model.numVertices} vertices, {model.numEdges} edges, {model.numSurfaces} surfaces");
 
-        var brushModel = new BrushModel(model.name);
-        brushModel.ImportMeshData(model);
-        
-        uq.GameAssets.SetWorldModel(brushModel);
-
-        // DEBUG
-        var worldGO = new GameObject(model.name);
-        for (int i = 0; i < brushModel.SubModelCount; ++i)
-        {
-            var subModel = brushModel.GetSubModel(i);
-            var subModelGO = new GameObject($"SubModel_{i}");
-            subModelGO.transform.SetParent(worldGO.transform);
-            
-            foreach (var surfaceMesh in subModel.SurfaceMeshes)
-            {
-                var meshGO = new GameObject(surfaceMesh.Mesh.name);
-                meshGO.transform.SetParent(subModelGO.transform);
-
-                var mf = meshGO.AddComponent<MeshFilter>();
-                mf.sharedMesh = surfaceMesh.Mesh;
-
-                var material = new Material(Shader.Find("Universal Render Pipeline/Simple Lit"));
-                uint texNum = surfaceMesh.Texture.TextureNum;
-                if (uq.GameAssets.TryGetTexture(texNum, out var texture))
-                {
-                    material.mainTexture = texture;
-                }
+        var worldModel = new BrushModel(model.name);
+        worldModel.ImportMeshData(model);
         
-                var mr = meshGO.AddComponent<MeshRenderer>();
-                mr.sharedMaterial = material;
-                mr.shadowCastingMode = ShadowCastingMode.Off;
-                mr.receiveShadows = false;
-                mr.lightProbeUsage = LightProbeUsage.Off;
-                mr.reflectionProbeUsage = ReflectionProbeUsage.Off;
-            }
-        }
+        uq.GameAssets.SetWorldModel(worldModel);
+        uq.GameState.NewMap(worldModel);
 
         return 1;
     }

Assets/Scripts/UniQuake.cs

@@ -35,7 +35,7 @@ public partial class UniQuake: MonoBehaviour
     public GameState GameState { get; private set; }
 
     private Action<string> logHandler;
-    private StringBuilder logBuffer = new StringBuilder();
+    private readonly StringBuilder logBuffer = new StringBuilder();
 
     void Start()
     {
@@ -158,8 +158,10 @@ public partial class UniQuake: MonoBehaviour
 
     private void OnDestroy()
     {
+        GameState.Destroy();
         GameAssets.Destroy();
     
+        gameModule.Destroy();
         renderModule.Destroy();
         systemModule.Destroy();