I find simple strech IK sample

I’m trying repeat strech IK rig from this video

But I didn’t succeed, and author of tutorial did not attach anything. I also tried to disassemble other people’s rigs like rigify. But there are a lot of unnecessary details that confuses me.

If anyone has a simple example (blend file) like in the video, I will be very grateful. Thanks.

I found this, and noticed that stretch parameter does not work for IK constraint. But it works for others.
On the left is what I did, and on the right is what the others did.
ik_strechq.blend (122.5 KB)

I’m not sure what your found structure is doing. It appears to be due to some hidden variable in the bones. Because these old bones are set to inherit rotation “legacy” I suspect that Blender is doing something to preserve the functionality of older files with a newer framework and not telling us about it.

To use stretch (at least in the latest versions of Blender) you have to enable stretch not only in the constraint, but on the IK settings for each bone that you want to stretch:

Here’s the file:

ik_strechq.blend (122.5 KB)