Set Line Length

If I have a number arbitrary lines that are in 3D and not aligned to one of the axes, is there any simple way to change the length starting from one of the ends?

Hello - Scale1D from one end is one way - snap to one end, then the other end, then typein the desired length and Enter. One by one though - if you want to set all line lengths the same, you can use a script.


What if I want an absolute length in inches, rather than a scale factor? I don’t see an option for that in Scale1D.

To scale an object from an arbitrary size to a specific one

  1. Use the origin point and the first reference point to establish the original size of the object.
  2. Type the new size for the second reference point.
    When scaling by dragging, the scale factor becomes the default the next time you use that scale command.

More about scale command.


Hello - you can type in units for the scaling distance constraint 5", 2c, 35mm etc.


Hi , no more hacky way is to make the arbitrary lines longer than needed, then use sub-curve on each line. Start at end and type in length desired.—Mark

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SubCrv will work well for shortening… Of course if you already know…
Also, @miano, in case it helps, here’s a plug-in that has a bunch of tools, all guaranteed slightly tested:


CurveAndArcUtilities.rhp (52 KB)

You’ll need to un-block the rhp file in its Properties, then drag and drop onto a Rhino window from the save location.


Can also use Scale instead of Scale1D for scaling lines.
Scale command
Snap to end which is to remain fixed.
Snap to other end. The “scale factor” option is now turned off.
Enter desired length

The scale factor option is disabled after the second reference point is selected.