Bone alignment on Y-axis changes when going from Pose to Edit to Pose

Hi,

I need to animate an industrial robot and I´m working on rigging it. Everything is working as it should in side view, but when I´m looking at it from top view the alignment of the bones changes when going from Pose to Edit and then back to Pose, see the attached image.

I have no idea what I´m doing wrong and how to fix it so please help me!

I had already assigned the material to the bones when I realized the problem but fortunatelly I had a copy from before assigning saved.

All the best

/Sussi

Attachments


We honestly can’t help without a blend to look at. There are too many variables involved for guesses.

It could be unapplied location rotations and scales to the mesh objects, misaligned bone axes, improper constraint values, order of constraints in the constraint stack, parenting issues, dependency loops…etc…etc.

My guess is a dependency loop based on the pose, edit and pose switching causing the issues.

If you could create a demo file to upload, that would help us help you. Use pasteall.org if you can’t upload here.

Good luck!

Yes of course, I should have realized that myself, I apologize.

Since the model does not belong to me and it´s part of a larger work related scene I´m only uploading the rig itself. The problem is still there, if you go into edit mode from either pose mode or object mode and back the bones move like in my image earlier (all I did was press tab and then tab).

You can download the file here:

All the best and I´m thankful for any help.

/Sussi

It’s a dependency issue and unapplied location of the armature. I’ll need more info to solve it as I do not know the end goal for the rigs movement. Could you create a screenshot to diagram the movements you want to create? I need know the main rotation points and where there should be limits. Any additional info would help.

Attachments


Ok, lets see if I can explain how I want the movements to be.

So, the robot isn´t yet attached but in this image I have rotated bone #6 and you can see how the bones have turned, that´s how I want the robot to work aswell.

I numbered the bones and parts of the robot that belong together. Bone #3 is just there to keep #9 from rotating and so that #7 and #4 stays moves together, I´m not even sure if #3 is necessary. I watched a tutorial on rigging a piston and used what I saw there. #9 is to control the telescopic part #1 if it needs to be extended. I didn´t want to extend it always. The setup of bone #1, #2 and #8 is according to the tutorial I watched.

#5 should not rotate but #4 must rotate from the connection point. #5 and #3 are the same length as is #4 and #7.

Did I make it any clearer?

Should I apply the rotation, scale and location before making the constraints?

As you probably can tell I´m a beginner in rigging but I try my best to learn.

Oh, yes, it´s this robot:

All the best

/Sussi

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This is the best I can do with the info provided. Hopefully it is helpful to you.

The rig works with an IK constraint. The main controls are the main.control.control and main.control.bone. main.control.bone (#6 in your image) was repositioned to be the base swivel point. All other bones should move automatically when moving main.control.control. You can also rotate arm.01 if you wish. I would categorize it as a “tweak” bone for the arm movement. Use it to fine tune the amount of telescoping of the arm after the main.control.control is placed.

You should be able to trace how everything works by looking at each bone’s parent and the constraints acting upon them. I’d be happy to answer any question about the setup.

I noticed that you unchecked some inherit location or scale boxes in bone properties. This is not a good idea. It makes debugging the rig much harder. I know it’s common to see people do this on youtube tutorials, but avoid it if possible. It makes creating a working root bone nearly impossible. I locked the scale transforms to prevent scaling a bone by accident.

I also added a root bone at the world center and aligned with the world axes. All rigs should have one. (Unless you are making a rig to export for games.)

You mentioned that you are new to rigging. There is not a better tutorial out there then Humane Rigging. Nathan Vegdahl teaches rigging concepts and how to problem solve to create rigs for any situation. I highly recommend it if you are serious about rigging.

Good luck on your project!

DanPro

Attachments

Robot_forum.DP.blend (630 KB)

Thank you very much DanPro, for taking the time and helping me!

I will do my best to try and understand the armature and to assign the right faces to the right bones. I have started but realized I needed more bones and rotation posibilities after the control.control bone. The tool at the end of the arm has two turning points aswell.

And thanks for the tip on Humane Rigging, I will definitely take a look at that. I´m a cloud member and had actually already downloaded the course but hadn´t watched it yet. I will do so now. I somehow imagined that it would be different rigging a machine.

/Sussi

Here is an updated rig with some simple box meshes to approximate the robot. Also added a new bone to the tip to rotate the suction cup end piece.

All controls are on bone layer one and have custom bone shapes applied. All of the mechanism bones are now on layer two. Also, I’ve added appropriate transform locks to the controls so the robot rig should work like the one posted.

Good luck!

Attachments

Robot.DP.02.blend (658 KB)

That´s awesome!

Thank you very much for all your help!

/Sussi

Just wanted to once again thank you for your help DanPro! I ended up doing my own rig but I learned a lot from watching your rig and the Humane Rigging course! It took me a few tries but it turned out pretty good at the end.

I´m finished with animating the two robots and now there will be lots of render time and putting it all together (which I will do in after effects).

I´ll post it in the forum when it´s done :slight_smile:

All the best!

/Sussi