Coordinate Systems SOLIDWORKS uses a system of coordinate systems with origins. A part document contains an original origin. Whenever you select a plane or face and open a sketch, an origin is created in alignment with the plane or face. An origin can be used as an anchor for the sketch entities, and it helps orient perspective of the axes. A three-dimensional reference triad orients you to the X, Y, and Z directions in part and assembly documents. Part origin (one in each part document) Sketch origin (one for each new sketch) Inferencing to an assembly origin (isometric orientation) Reference triad in part and assembly documents Parent topicWorking with Models Planes Selection Methods Selection Feedback Grid and Snap Dragging Orientation