From 9ae4761d6e6824e591993e4a5ca41b51db4aa79a Mon Sep 17 00:00:00 2001
From: ousttrue <ousttrue@gmail.com>
Date: Tue, 21 Jul 2026 11:09:05 +0900
Subject: [PATCH] add Vrm10RuntimeExpression.Reload

---
 .../Components/Expression/ExpressionMerger.cs | 15 ++++++++-
 .../Vrm10Runtime/Vrm10RuntimeExpression.cs    | 33 +++++++++++++++++--
 2 files changed, 45 insertions(+), 3 deletions(-)

diff --git a/Packages/VRM10/Runtime/Components/Expression/ExpressionMerger.cs b/Packages/VRM10/Runtime/Components/Expression/ExpressionMerger.cs
index de9a6a55f..6d658a03d 100644
--- a/Packages/VRM10/Runtime/Components/Expression/ExpressionMerger.cs
+++ b/Packages/VRM10/Runtime/Components/Expression/ExpressionMerger.cs
@@ -32,6 +32,16 @@ namespace UniVRM10
             bool isPrefabInstance,
             IReadOnlyDictionary<Transform, TransformState> initPose)
         {
+            InitializeOrReload(expressions, root, isPrefabInstance, initPose);
+        }
+
+        internal void InitializeOrReload(VRM10ObjectExpression expressions,
+            Transform root,
+            bool isPrefabInstance,
+            IReadOnlyDictionary<Transform, TransformState> initPose)
+        {
+            Dispose();
+
             m_clipMap = expressions.Clips.ToDictionary(
                 x => expressions.CreateKey(x.Clip),
                 x => x.Clip,
@@ -79,9 +89,12 @@ namespace UniVRM10
             m_boneTransformBindingMerger.AccumulateValue(key, value);
         }
 
+        /// <summary>
+        /// 未初期化呼び出し及び再呼び出しで正常に動くように注意 !
+        /// </summary>
         public void Dispose()
         {
-            m_materialValueBindingMerger.Dispose();
+            m_materialValueBindingMerger?.Dispose();
         }
     }
 }
diff --git a/Packages/VRM10/Runtime/Components/Vrm10Runtime/Vrm10RuntimeExpression.cs b/Packages/VRM10/Runtime/Components/Vrm10Runtime/Vrm10RuntimeExpression.cs
index 3c13e449f..b28e9741f 100644
--- a/Packages/VRM10/Runtime/Components/Vrm10Runtime/Vrm10RuntimeExpression.cs
+++ b/Packages/VRM10/Runtime/Components/Vrm10Runtime/Vrm10RuntimeExpression.cs
@@ -10,6 +10,7 @@ namespace UniVRM10
     {
         public static IExpressionValidatorFactory ExpressionValidatorFactory = new DefaultExpressionValidator.Factory();
 
+        private bool _isPrefabInstance;
         private List<ExpressionKey> _keys = new List<ExpressionKey>();
         private Dictionary<ExpressionKey, float> _inputWeights = new Dictionary<ExpressionKey, float>();
         private Dictionary<ExpressionKey, float> _actualWeights = new Dictionary<ExpressionKey, float>();
@@ -25,12 +26,13 @@ namespace UniVRM10
         public float LookAtOverrideRate { get; private set; }
         public float MouthOverrideRate { get; private set; }
 
-        internal Vrm10RuntimeExpression(Vrm10Instance target, 
-            ILookAtEyeDirectionApplicable eyeDirectionApplicable, 
+        internal Vrm10RuntimeExpression(Vrm10Instance target,
+            ILookAtEyeDirectionApplicable eyeDirectionApplicable,
             bool isPrefabInstance,
             IReadOnlyDictionary<Transform, TransformState> initPose
             )
         {
+            _isPrefabInstance = isPrefabInstance;
             _merger = new ExpressionMerger(target.Vrm.Expression, target.transform, isPrefabInstance, initPose);
             _keys = target.Vrm.Expression.Clips
                 .Select(x => target.Vrm.Expression.CreateKey(x.Clip))
@@ -55,6 +57,33 @@ namespace UniVRM10
             _eyeDirectionApplicable = eyeDirectionApplicable;
         }
 
+        /// <summary>
+        /// target.Vrm.Expression に基づいて再初期化する。
+        /// 
+        /// https://github.com/vrm-c/UniVRM/issues/2802
+        /// 
+        /// ex.
+        /// vrmInstance.Vrm.Expression.AddClip(ExpressionPreset.custom, myCustomExpression);
+        /// vrmInstance.Runtime.Expression.Reload(vrmInstance);
+        /// 
+        /// </summary>
+        public void Reload(Vrm10Instance target)
+        {
+            // 最新の表情定義に基づいて再生成
+            _merger.InitializeOrReload(target.Vrm.Expression, target.transform, _isPrefabInstance, target.Runtime.InitPose);
+            _keys = target.Vrm.Expression.Clips.Select(x => target.Vrm.Expression.CreateKey(x.Clip)).ToList();
+
+            // リロード時の一瞬の表情カクつきを防ぐため、既に設定されていたウェイトを引き継ぐ
+            var oldInputWeights = _inputWeights;
+            _inputWeights = _keys.ToDictionary(x => x, x => 0f);
+            foreach (var key in _keys)
+            {
+                if (oldInputWeights.ContainsKey(key)) _inputWeights[key] = oldInputWeights[key];
+            }
+            _actualWeights = _keys.ToDictionary(x => x, x => 0f);
+            _validator = ExpressionValidatorFactory.Create(target.Vrm.Expression);
+        }
+
         public void Dispose()
         {
             _merger?.Dispose();