有大神帮我看看规则哪里出错了么，这是一个种树的规则，话费有酬

我想把树分成两种属性MDL 和MIN然后MDL从一个文件夹随机选择OBJ .MIN从另一个文件夹里选
@range("MIN" ,"MDL")
attr size = "MDL"
objTree=
case size == "MDL" :fileRandom("assets/objTree/*.obj")
else:fileRandom("assets/Plants/*.obj")
lot-->
scatter(surface,1, uniform){CreatTree}
CreatTree-->
alignScopeToAxes()
i(objTree)