IK limits 🤦‍♂️

[Jaco_Pretorius]

Lot of time spent on this and it still has issues…

The body is driven by its own IK, while the Look target drives the head, including head tilt, which I finally got right… (Combination of Locked-Track and Rotation-Limit bone-constraint modifiers that use the Look bone as target.)

The IK was incredibly frustrating and wonky. I got the previous rig perfect and IK felt like a wrecking ball… To compromise I put a Limit-Location bone-constraint modifier on the BodyIK bone to keep it in one plane only. Any Z-rotation will have to be taken care of by the LampBase. I’m not getting the parrallelogram effect on the hinges and LArm1 goes out of sync with the rest of the rig. Tried adding more bones but it became too much and I had to settle on a workable solution that isn’t perfect but does the trick… Great experience but I clearly have a lot to learn still…

ALSO: Can’t stress enough how much lighting is reliant on your geometry. I could not figure out why my light falloff didn’t work for almost an hour… I just needed edges/bevel on my stage, and to make it big enough and the light looked correct (Michael totally covered this but I forgot ).

[Capricas_Kirito]

As I made a very similar lamp to yours, I suspect we ran into many of the same issues. The way I addressed the indipendant movement of the paired arms was to set up the rig with a single control chain:

Head —> Neck —> Front Upper Arm —> Elbow —> Front Lower Arm —> Base

The remaining bones, such as the rear arms, I controled with Copy Rotation restraints

[Jaco_Pretorius]

Thanks for the advice and sorry for the late response.

I’m hoping to finish off the Lamp section soon but still having fun with exporting… (This week’s problem )

I used your advice to create the auto-keyframed animation here:

Auto Keyframing test animation

My hint: I found auto-keyframing at 12 fps and then scaling everything in the dope-sheet by 2 (from frame 1) and setting 24fps smooths out the auto-keyframing somewhat. This a combination of auto-keyframing and standard keyframing with a IK-rigged model and is just a quick test without many tweaks. Just animating the camera and base with auto-keyframing and moving one IK handle for the flex.: https://aws1.discourse-cdn.com/business5/uploads…

There were still artifacts where the arm bones would go out-of sync with the lower hinge bolts because in my reference the lower arms do not form a perfect parallelogram so the rotation limit got noticeably wrong at the extremes.

Got a little obsessed with making it work with IK without artifacts and puzzled over this article for a while:

Bone Parallelogram Connection Translations and Parenting

Eventually managed to come up with this rig for the lower body of the lamp (non-parallel nature of the bones made obvious here to show a generalized 4-bar pivot-link rig (This might interest you @DustinWoods)):

I go through the various constraints in the video above so I hope it shows.
The only weird thing to note is that LArm1->UArmIK->Main_IK_Target is the main IK chain (and UArmIK and Main_IK_Target will not have geometry parented to them). Also, the Copy Rotation modifiers copy the inverted follower rotation.
This is the armature hierarchy:

I’ll be using that for the lower part of my final rig which still needs the springs added.

[Jaco_Pretorius]

This shows the evolution of the rig: