在MasterCAM中，进行2D轮廓铣削、挖槽等刀路定义时，需要对那些首尾相接的图素轮廓或边界进行选择-In MasterCAM, make 2D contour milling, Trench Road, such as the definition of a knife, there is a need both for those pixels of the phase contours or borders to choose