diff --git a/src/scene/texture/transform/NormalMap.php b/src/scene/texture/transform/NormalMap.php
index 27161e1..fc9dcfd 100644
--- a/src/scene/texture/transform/NormalMap.php
+++ b/src/scene/texture/transform/NormalMap.php
@@ -15,7 +15,7 @@ class NormalMap extends TextureBase
 
     
     /**
-     * @var integer TODO: 具体作用尚未明确，（固定取值：1）
+     * @var integer 高度缩放：(0-5)的小数
      */
     public $scale = 1;