https://blog.gongquiz.com/2022/07/29/%eb%8b%a4%ec%9d%8c-%ec%a4%91-%ea%b3%b5%ec%8b%ac%ec%a0%90-%ea%b8%b0%eb%b2%95cdpcommon-depth-point-method%ec%97%90-%eb%8c%80%ed%95%9c-%eb%b0%94%eb%a5%b8-%ec%9d%91%ec%9a%a9%ec%a7%80%ec%a7%88/