优化，增加表情幅度

examples/3d/blendshapeAnimator.js

@@ -36,7 +36,8 @@ class BlendShapeAnimator {
         this.expressionParams = config.expressionParams || {
             intervalMin: 3000,
             intervalMax: 8000,
-            speed: 400
+            speed: 400,
+            strength: 1.0
         };
 
         this.enabledExpressions = new Set();
@@ -269,12 +270,20 @@ class BlendShapeAnimator {
 
     // 设置空闲动画
     setIdleAnimation(name, target, duration = 200, easing = 'easeOutQuad') {
+        const currentValue = this.morphTargetAdapter
+            ? this.morphTargetAdapter.getInfluence(name) || 0
+            : (this.idleAnimations[name]?.target || 0);
+
+        const anim = this.idleAnimations[name] || {};
+        const unchanged = Math.abs(currentValue - target) < 1e-4 && Math.abs((anim.target ?? 0) - target) < 1e-4;
+
         this.idleAnimations[name] = {
             target: target,
             duration: duration,
             easing: easing,
-            startTime: null,
-            startValue: this.idleAnimations[name]?.target || 0
+            // 如果目标基本不变，保持当前起点，避免反复重新插值导致抖动
+            startTime: unchanged ? performance.now() : null,
+            startValue: currentValue
         };
     }
 
@@ -305,7 +314,9 @@ class BlendShapeAnimator {
                 if (anim.target === 0) {
                     delete this.idleAnimations[name];
                 } else {
-                    anim.startTime = null;
+                    // 目标保持不变，锁定在当前值，避免反复重新插值造成抖动
+                    anim.startValue = anim.target;
+                    anim.startTime = now;
                 }
             }
         }