9.5.2

234 • CHAPTER 7
OBJECTS MENU • NURBS • 235
Parallel Movement
If this option is enabled, the contour is swept in a parallel manner (i.e. it is not rotated at all).
Banking
If Banking is enabled, the contour spline will lean into the curves of the path spline (CINEMA 4D will
calculate the banking by considering the curvature of the path). The initial banking angle is set to the
average plane of the path spline, which is calculated from the position of the path’s spline points. The
banking angle must be chosen at random for straight lines since they cannot dene a plane. In this case,
turn off banking to make the contour will run parallel to the path spline’s XZ plane.
Use Rail Direction
Use Rail Direction enabled (left) and disabled (right).
If this option is enabled, the rail spline will inuence the rotation of the contour about its Z-axis.
The Z-rotation applied to each contour position is equal to the angle between the contour’s local
+X axis and the projection onto the contour’s local XY axis of the vector that connects the contour’s
local origin to the matching point on the rail spline. This vector connects spline points on the path to
corresponding spline points on the rail and applies linear interpolation to determine corresponding
points on paths of the splines between points.
The best way to create a rail spline is to make a copy of the path spline, then adjust the location of the
rail spline points to get the desired effect.
Use Rail Scale
If this option is enabled, the rail spline can be used to alter the scale of the contour along the path.
The scale factor applied to each contour position is equal to the distance of the vector connecting
the contour’s local origin to the matching point on the rail spline. This vector connects spline points
on the path to corresponding spline points on the rail and applies linear interpolation to determine
corresponding points on paths of the splines between points.