Constraints & kinematics help

[Merlinw (Merlin)]

Hello, I am trying to learn and understand constraint and kinematics in animating. In the first screenshot below, the system is as follows: Rod number 3 is rotary connected to rod number 1 and rod number 4 is rotary connected to rod number 2. Rods 3 and 4 are also rotatably connected to each other. After making these assumptions, I took the second ss I made myself manually, but I want to do this procedurally using kinematics and constraints. What I want is to automatically calculate the situation in the second picture and move it instantaneously as I move stick number 2 towards +z.

ss 1

ss 2

I’ve seen it done with bones before, but I can’t find videos about that. Can you send me a video or resource where I can do this? or if this is easy to do and you can explain I would be grateful. Thank you in advance…

[bandages]

To work with inverse kinematics, you need to be using bones, not objects. You can parent the objects to the bones if you want.

Doing this with bones is relatively simple:

1 and 2 are unparented controls. 3 is parented to 4 which is parented to 2. 3 has an IK constraint targeting 1, with a chain length of 2: encompassing itself and its parent 4, 2 bones.

The exact directions that the bones point doesn’t much matter, so I’ve chosen parenting and directions for convenience. We could reverse 3 and 4, but then we’d need a new bone to tell Blender exactly where 4 points to on 2. I chose the parenting and bone direction I did to avoid that.