[MA:Arnold] How to disable visibility in alpha channel?

https://answers.arnoldrenderer.com/questions/3004/skydome-light-how-to-disable-visibility-in-alpha-c.html


http://maya.indyzone.jp/2017/08/15/arnold5%E3%81%AE%E3%82%B9%E3%82%AB%E3%82%A4%E3%83%89%E3%83%BC%E3%83%A0%E3%83%A9%E3%82%A4%E3%83%88%E3%81%AF%E5%8F%AF%E8%A6%96%E5%8C%96%E3%81%AE%E8%AA%BF%E6%95%B4%E3%81%8C%E5%87%BA%E6%9D%A5%E3%81%BE/