How to create a straight tube shape into a circle animation in blender?

I’m learning Blender, so I can use it to make electricity animation videos. I have been trying to turn a straight line with one end into a circle. Who knows how to achieve this animation effect?

Try this out. All about the curve modifier.

I’m thinking a curve with a bevel profile, then add hooks and animate them to perform the effect. The problem i see there is getting the motion smooth. Likewise using shape keys may not give the desired result as they tend to interpolate in a linear manner.

Well, this reignited my hatred for that direct descendant of the devil called the simple deform modifier.

Don’t ask me why the values are what they are; it was trial and error. Only blender developers understand the inner workings of that abomi… I mean modifier.

I ended up using a mesh for the wire because curves don’t support vertex groups and I needed those to limit the influence of the simple deform modifiers.


wire_bend_and_curl.blend (925.1 KB)

The file should speak for itself really. One modifier for each deformation.


How to make this animation in blender to unity

I want to make an animation depicting the process of making a rope knot. I tried doing it with curves, with arrays but it only works in blend when exporting to unity it all doesn’t work. I also tried with the alembic file it works perfectly but the textures are missing, anyone have any ideas to help me?

Hah, so you actually went through with it. I gave up after half an hour so when I tried it after this post:

Yeah at some point it just became a project in stubbornness. I knew it had to be possible so it became a challenge to make it work.

But in hindsight I don’t feel its very practical to use the Simple deform modifier. It just takes too much time to figure it out with the empties and everything. It also forces you to use vertex groups as masking if you are going to work with multiple bends so that gets complicated quickly. It appears to be a logical choice but in practice its just very cumbersome.

The simplest approach is just a simple mesh tube and an FK chain with short bones for deformation. Since the rotations all take place in a plane this is actually really straightforward to manipulate. When posing just set the origin to individual origins and select more or less bones for a smaller or bigger radius.

If you keep your edge loops and bones in sync (I chose three loops per bone) then automatic weighting with a Corrective smooth modifier with smooth type set to length weight will give you very smooth deformations. Throw a subdivision surface on top for final polish.

copper_wire_simple_fk.blend (1.6 MB)

Nice! Thanks for sharing!

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