Hi mford610,
Please have a look at the screen capture:
https://www.amazon.com/clouddrive/share/mwMpPqIrtgVnqFjMA4u6cRGhcrCDHJv92OzkJ5mO1yT
The Tracer is not interested in dimensions, the only information the Tracer uses is the position. If that is an object Axis or a point (Trace Vertices). These positions are then used to trace or connect, based on the Tracer’s settings.
There is nothing more to it, no object-displacement.
Child objects use the parent as their “World” system. If the parent moves, they move; if it rotates, they revolve, or in some cases, rotate. If the parent scales, the child’s world shrinks or expands.
You have used in your example (Initial pos) three Nulls, no object with dimensions at all. It worked to create a Spline. If you moved a Null, the Spline produced by the Tracer changed.
We have four objects in the Tracer; they produce a spline with the vertices/point number 0, 1, 2, and 3.
• The first parent creates point number 0
• The child of this has a distance to the parent and produces point number 1
• The child of the other parent is the third entry in the Tracer list; hence it creates point 2
• Last in the Tracer List is the other parent and its position is making point 3
The Child objects are between the two parents. Since the B_Spline uses the points of the Spline (except start and endpoint) more like a SubDivision Surface. The two points in the middle are pulling on the spline. Hence the soft curvature.
Let me know if this works for you.
ENJOY.