diff --git a/src/scene/texture/procedural/ImageMap.php b/src/scene/texture/procedural/ImageMap.php
index a2faecc..da52dd0 100644
--- a/src/scene/texture/procedural/ImageMap.php
+++ b/src/scene/texture/procedural/ImageMap.php
@@ -16,9 +16,9 @@ class ImageMap extends TextureBase
     
     /**
      * @var string 亮度增益，当发光强度单位是 artistic 类型时，或是 坎德拉类型且坎德拉参数下勾选为（每平方米时）,可以设置此参数,分别
-     * 控制自发光颜色RGB三个通道的放大倍数；否则固定为 1 1 1
+     * 控制自发光颜色RGB三个通道的放大倍数；否则固定为 1
      */
-    public $gain = "1 1 1";
+    public $gain = 1;
 
     /**
      * @var float 校正光域网文件的gamma值，（固定取值：1）