point picker切割，分别有多点拾取，在产生的图像中拾取点信息。包涵几种例子，有人脸切割等例子。能更好的理解VTK poit功能与使用方法~-point picker cutting, more points were picked up in the resulting image pick-up point information. Bear with a few examples, some examples of cutting face. A better understanding of function and use VTK poit ~