How do I extend a line segment from only one endpoint?

How do create an animation that only extends a line (segment) from one endpoint while the other endpoint remains anchored? Here is an example of what I want to do in Blender:

You could animate the scaling of a cylinder with the origine placed at one of its ends.

Here’s a .blend file using my method.
Is the result what you want ?


growingLine.blend (331 KB)

Yes!!! This is exactly what I want. Now…how did you do that (I’m a noob)?

As I said upper, I’ve created scale keyframes on a cylinder with the origin placed at its end, here’s the method step by step :

  • Add a cylinder.

  • Select it and go in edit mode (tab)

  • select all the vertices and scale them in order to get the shape you want at the beggining of the animation (frame 1 in my .blend)

  • now you need to place the origin at the base of the cylinder instead of at its centre ; so select the centre vertex of the face of the cylinder you want to become the base.

  • press shift+S and choose “Cursor to Selected”

  • pass in object mode by pressing tab

  • place the origin of the cylinder at the 3D cursor place by pressing ctrl+alt+shift+C and choose “Origin to 3D Cursor”

  • you can rotate the cylinder if you want it not to be perfectly vertical but take care to do that in object mode not in edit mode.

  • now start the animation : you need to be at the start frame of your animation then select the cylinder, press I and choose scaling to create the first keyframe

  • in the header of the 3D view change the transform orientation from “global” to “local”

  • go at the end frame of your animation (frame 100 in my file)

  • now you need to scale the cylinder along its long axis (it must be the local Z axis if you follow my instructions) press S then Z then Z again move your mouse and when you reach the lenght you want for the end frame LMB click.

  • press I and choose scaling to create the end keyframe.

Now your animation is finished, you can go at the first frame and play it by pressing alt+A.

Thank you very much, Sliv. I followed your steps and recreated your animation. This is perfect! I really appreciate your help.