Roller Contact Contact point definition available for elastic contact surface description only. The contact point may contain several rollers. The rollers are located in the YLZL- plane of the element to which the contact point is attached. Besides the location, each roller is described by its length, which may be infinite, by its stiffness and dash pot damping. The location and orientation of a roller is defined by a point and an inclination angle referred in the local coordinate system of the contact surface element. A roller of finite length is shown below. The roller origin (starting point) is defined by the point (YR, ZR) and the inclination angle (ROTX) is defined by a clockwise rotation around the contact surface XL-axis. Pipe-in-Pipe Roller