9.5.2

1104 • CHAPTER 22
XPRESSO EDITOR • 1105
Spline
The Iteration node outputs all whole numbers from 0 to 100 one after the other. These numbers are
each divided by 100 to convert them to Real values in the range of 0.0 to 1.0. These Real values are then
passed to the Spline node’s Offset port, which causes the Spline node to output the coordinates of 101
positions along the spline.
This node outputs the coordinates of positions along a spline. You specify the position that you want
to check as a percentage, where 0% represents the start of the spline and 100% represents the end
of the spline. Depending on the Matrix Mode setting in the Attribute manager, the node outputs the
position in local coordinates or in global coordinates.
A spline can consist of one or more segments. If the spline has more than one segment, pass the
number of the segment that you want to examine to the Segment input port. Note that the rst
segment is accessed with the value 0, the second segment is accessed with the value 1, and so on.
If Use All Segments is enabled in the Attribute manager, the Offset value refers to the length of the
entire spline including all its segments. If the spline is composed of one segment only, you can ignore
the Segment port (the segment will be used automatically).
The way in which a spline is subdivided depends on its interpolation settings. For example, points
may be concentrated around the bends. This has implications if you want to move an object along the
spline at constant velocity — the spline must be subdivided evenly. Enable the Use Natural Distribution
option if you want the Spline node to output values that are equal distances apart.
The following output ports are available:
 Closed: Outputs a Bool value of 0 if the spline in open or 1 if the spline
is closed (splines can be closed by enabling the Close Spline option in the
Attribute manager).
 Length: Outputs the length of the chosen spline segment, as a Real
number.
 Position: Outputs the coordinates of a position along the spline (as dened
by the Offset value and the Matrix Mode setting).
 Segments: Outputs the total number of spline segments. When passing the
number of a segment to the Segment input port, keep in mind that the number
of the rst segment is 0.
 Tangent: Tangents dene the run of the curve before and after the position
along the curve. This port outputs the tangent for the chosen position along
the spline as a vector.