An arc guide is dependent on a guide part. If an arc guide is created, a workpiece to arc contact is automatically created. Its contact type can be represented as a sphere to extruded arc contact. As shown in Figure 1, the user first should define whether the contact direction is up or down of the guide. When a sheet body is contacted with the arc guide, the plus normal direction is in up or down direction of a relative position vector from the arc reference position to the center point of the sheet body. The tangent direction can be determined from the specified normal and depth directions by the right hand rule. The plus direction of Guide velocity is determined as the plus tangential direction.
Figure 1 Arc Guide