Align Group to Line


I’m using Rhino to design an outdoor model railroad and part of that is the track plan. There are model railroad CAD programs and one of the very handy commands in them is to align one track object with another – say aligning the curved leg of a switch with a curved piece of track.

I’ve looked at the Rhino Align command to do that for me and at some of the posts on using Align and I can’ seem to figure out how to use it for my application.

My work around is to Move the switch group so that it links with the curved track piece – centerlines in both cases. The issue then is the centerlines of the track and the switch are discontinuous at the joint. See photos.

I then extend each curve with a straight line, compute the angle, then rotate the switch group so the centerline curves of both objects are continuous. Doable but tedious after a while.

Any advice, suggestions, comments?

Hilary Smith
Pacific NW

The simplest thing is to make the lines that you need for aligning tangents PART OF the blocks, just have them on a different layer or something, then you can just use Orient to snap them into place.

Hi Hillary - Orient, with ‘Smart tracking’ on should help here.

I made my smart tracking tangent lines red so they are slightly more visible but still hard to see:

Does that solve the right problem? You can use the short lines at the ends as the orientation references as well - that probably makes more sense.


My thanks to Jim for a clever solution and to Pascal for his very trick way of putting the track objects together. My day is made.