feat(component): LODGeneratorHelper uses LODGeneratorPreset

LODGeneratorHelper has two new properties,
A LODGeneratorPreset obj ref and a "customization" toggle.
If customization is enabled (default), the helper drives all properties itself.
If customization is disabled, properties are driven by a specified preset.
If no preset is specified, defaults matching previous behavior are used.

Author: scoan-sd

Editor/LODGeneratorHelperEditor.cs

@@ -35,6 +35,8 @@ namespace UnityMeshSimplifier.Editor
     [CustomEditor(typeof(LODGeneratorHelper))]
     internal sealed class LODGeneratorHelperEditor : UnityEditor.Editor
     {
+        private const string LodGeneratorPresetFieldName = "lodGeneratorPreset";
+        private const string CustomizeSettingsFieldName = "customizeSettings";
         private const string FadeModeFieldName = "fadeMode";
         private const string AnimateCrossFadingFieldName = "animateCrossFading";
         private const string AutoCollectRenderersFieldName = "autoCollectRenderers";
@@ -54,6 +56,8 @@ internal sealed class LODGeneratorHelperEditor : UnityEditor.Editor
         private const float RendererButtonWidth = 60f;
         private const float RemoveRendererButtonSize = 20f;
 
+        private SerializedProperty lodGeneratorPresetProperty = null;
+        private SerializedProperty customizeSettingsProperty = null;
         private SerializedProperty fadeModeProperty = null;
         private SerializedProperty animateCrossFadingProperty = null;
         private SerializedProperty autoCollectRenderersProperty = null;
@@ -82,6 +86,8 @@ internal sealed class LODGeneratorHelperEditor : UnityEditor.Editor
 
         private void OnEnable()
         {
+            lodGeneratorPresetProperty = serializedObject.FindProperty(LodGeneratorPresetFieldName);
+            customizeSettingsProperty = serializedObject.FindProperty(CustomizeSettingsFieldName);
             fadeModeProperty = serializedObject.FindProperty(FadeModeFieldName);
             animateCrossFadingProperty = serializedObject.FindProperty(AnimateCrossFadingFieldName);
             autoCollectRenderersProperty = serializedObject.FindProperty(AutoCollectRenderersFieldName);
@@ -128,6 +134,9 @@ private void DrawGeneratedView()
 
         private void DrawNotGeneratedView()
         {
+            EditorGUILayout.ObjectField(lodGeneratorPresetProperty, typeof(LODGeneratorPreset));
+            EditorGUILayout.PropertyField(customizeSettingsProperty);
+
             EditorGUILayout.PropertyField(fadeModeProperty);
             var fadeMode = (LODFadeMode)fadeModeProperty.intValue;
 
@@ -631,7 +640,7 @@ where go.transform.IsChildOf(ourTransform)
 
             if (prefabGameObjects.Any())
             {
-                EditorUtility.DisplayDialog("Invalid GameObjects", "Some objects are not children of the LODGenerator GameObject," + 
+                EditorUtility.DisplayDialog("Invalid GameObjects", "Some objects are not children of the LODGenerator GameObject," +
                     " as well as being part of a prefab. They will not be added.", "OK");
             }
 #endif

Runtime/Components/LODGeneratorHelper.cs

@@ -35,6 +35,12 @@ namespace UnityMeshSimplifier
     public sealed class LODGeneratorHelper : MonoBehaviour
     {
         #region Fields
+        [SerializeField, Tooltip("The LOD Generator preset to use.")]
+        private LODGeneratorPreset lodGeneratorPreset = null;
+
+        [SerializeField, Tooltip("Whether to enable customization of preset-derived generation settings.")]
+        private bool customizeSettings = true;
+
         [SerializeField, Tooltip("The fade mode used by the created LOD group.")]
         private LODFadeMode fadeMode = LODFadeMode.None;
         [SerializeField, Tooltip("If the cross-fading should be animated by time.")]
@@ -57,13 +63,41 @@ public sealed class LODGeneratorHelper : MonoBehaviour
         #endregion
 
         #region Properties
+        /// <summary>
+        /// Gets or sets a LOD generator preset. Presets can be used to drive simplification options and levels in a sharable way.
+        /// </summary>
+        public LODGeneratorPreset LodGeneratorPreset
+        {
+            get { return lodGeneratorPreset; }
+            set { lodGeneratorPreset = value; }
+        }
+
+        /// <summary>
+        /// Gets or sets if the simplification options and levels should be customizable, versus driven by the specified preset.
+        /// </summary>
+        public bool CustomizeSettings
+        {
+            get { return customizeSettings; }
+            set { customizeSettings = value; }
+        }
+
         /// <summary>
         /// Gets or sets the fade mode used by the created LOD group.
         /// </summary>
         public LODFadeMode FadeMode
         {
             get { return fadeMode; }
-            set { fadeMode = value; }
+            set
+            {
+                if (!customizeSettings)
+                {
+                    fadeMode = value;
+                }
+                else
+                {
+                    WarnDisabledCustomization();
+                }
+            }
         }
 
         /// <summary>
@@ -73,7 +107,17 @@ public LODFadeMode FadeMode
         public bool AnimateCrossFading
         {
             get { return animateCrossFading; }
-            set { animateCrossFading = value; }
+            set
+            {
+                if (!customizeSettings)
+                {
+                    animateCrossFading = value;
+                }
+                else
+                {
+                    WarnDisabledCustomization();
+                }
+            }
         }
 
         /// <summary>
@@ -91,7 +135,17 @@ public bool AutoCollectRenderers
         public SimplificationOptions SimplificationOptions
         {
             get { return simplificationOptions; }
-            set { simplificationOptions = value; }
+            set
+            {
+                if (!customizeSettings)
+                {
+                    simplificationOptions = value;
+                }
+                else
+                {
+                    WarnDisabledCustomization();
+                }
+            }
         }
 
         /// <summary>
@@ -110,7 +164,17 @@ public string SaveAssetsPath
         public LODLevel[] Levels
         {
             get { return levels; }
-            set { levels = value; }
+            set
+            {
+                if (!customizeSettings)
+                {
+                    levels = value;
+                }
+                else
+                {
+                    WarnDisabledCustomization();
+                }
+            }
         }
 
         /// <summary>
@@ -124,14 +188,57 @@ public bool IsGenerated
 
         #region Unity Events
         private void Reset()
+        {
+            autoCollectRenderers = true;
+            ResetPresetDerivedSettings();
+        }
+
+        private void OnValidate()
+        {
+            if (!customizeSettings)
+            {
+                UpdateSettingsFromPreset();
+            }
+        }
+        #endregion
+
+        private void WarnDisabledCustomization()
+        {
+            Debug.LogWarning($"Attempted to set a preset-driven property on a {typeof(LODGeneratorHelper)} while customization is disabled. Enable customization first.");
+        }
+
+        private void ResetPresetDerivedSettings()
         {
             fadeMode = LODFadeMode.None;
             animateCrossFading = false;
-            autoCollectRenderers = true;
             simplificationOptions = SimplificationOptions.Default;
-
             levels = LODLevel.GetDefaultLevels();
         }
-        #endregion
+
+        private void UpdateSettingsFromPreset()
+        {
+            // Retain copy of levels so any specified renderers can survive reset
+            LODLevel[] previousLevels = (LODLevel[])levels.Clone();
+
+            // Copy settings from preset, or use defaults if no preset specified
+            if (lodGeneratorPreset != null)
+            {
+                fadeMode = lodGeneratorPreset.FadeMode;
+                animateCrossFading = lodGeneratorPreset.AnimateCrossFading;
+                simplificationOptions = lodGeneratorPreset.SimplificationOptions;
+                levels = (LODLevel[])lodGeneratorPreset.Levels.Clone();
+            }
+            else
+            {
+                ResetPresetDerivedSettings();
+            }
+
+            // Copy specified renderers over
+            int rendererCopyCount = Mathf.Min(levels.Length, previousLevels.Length);
+            for(int idx = 0; idx < rendererCopyCount; idx++)
+            {
+                levels[idx].Renderers = (Renderer[])previousLevels[idx].Renderers.Clone();
+            }
+        }
     }
 }