Model Railroad Track Planning in Rhino 6

Hello All:

I have been using Rhino for some time in model railroad design – locomotives and cabooses primarily – but my needs and abilities are still quite modest. Currently I am designing an outdoor model railroad that includes “mountains” meaning I need to be able to draw a line representing the track and have a percentage grade assigned to it so it rises or declines in the z dimension.

Ideally I would like to take a curving line in the X-Y plane, indicate a start point and a percentage and have the line rise or fall by that percentage through the end point. I thought of using Setpt and then connecting the points but that seems like a slog.

I would be grateful for any ideas or assistance. Oh, and Happy Holidays to all.

Hilary Smith
Pacific NW

Hi Hillary - here’s what I’d do, pending some further thought about doing it right… tomorrow.

  • Make a straight line at the desired slope and the length of your run of track (curve).
  • Turn on edit points, not control points on the curve. (EditPtOn)
  • Window select all the points and ExtractPt
  • Flow the points from the curve to the line.
  • SetPt each of the actual edit points on the curve to the Z value of the corresponding flowed point on the line.

There is probably a better and more compact way to do that, but that’s what comes to mind at the moment - also it is likely easy enough automate this with a script.


1 Like

This might help:


Thanks for the nifty grade calculator. It’s a good reference.



Thank you for taking the time to formulate and send me a solution. It works well – I’m very grateful!