Problem with Lamp Stem's constraint when apply inverse kinematics

Hello,
I am an issue with Lamp Stem’s constraint. When I use Look to control the lamp, the Lamp Stem moves X and Z which I’ve constrained them already, and Y is unconstrained. I couldn’t figure out the problem.

1 Like

Do you use IK?

And is the length of the IK chain -1?

1 Like

Yes, I use inverse kinematics and chain is 4.

1 Like

-1

Need to be three I think!

1 Like

I have an experiment with inverse kinematics. Why is the bone constraint not working when I apply IK? the bones are moving through themself.

1 Like
  • Did you use length = 3 for 4 bones?
  • Did you add bone restrictions for the bone rotations?

if I use 3 chain then the bottom bone won’t move at all. Yes, I use the bone constraint to restrict bone rotation.

1 Like

That is correct. You need to connect the bone to a parent something (like an empty, or lamp base_.

Adding restrictsing is hard to do, because of the 360 rotation minus/positive trurns and local world coordinates. A lot of things can go wrong. Check everything.
Start small using two bones. expanding the chains.

2 Likes

But with BONE CONSTRAINT, the bones are not suppose to move through themself. And the bottom bone should move rotating Y axis, not X and Z.

1 Like

with 3 chains, bottom bone not moving or rotating Y axis.

1 Like

It seems the IK is override the BONE CONTRAINT, when I check the individual bone constraint movement, it works. But when I use control bone (the cone) everything is not working. How can I fix this problem?

1 Like

Unsure … because you’ve 2.9 I’m using 3.3 things are changing.

They have their own (limited) set of “constraints” through the Inverse Kinematics panel, and that’s all – making the solvers use/understand all Blender’s constraints is difficult work.

2 Likes

I am sure this was covered in the lectures. IK has its own constraints, perhaps it is worth rewatching the start of using IK looking out for the part on constraints.

2 Likes

Yesssss! Thank you. :smiling_face_with_three_hearts: :smiley:It works, everything is working now.

3 Likes

In bone properties, I locked the Lock IK in the inverse kinematics drop down.

1 Like

Should I use both bone constraint and Ik constraint? Or Ik constraint is good enough for controlling the lamp.

1 Like