Answered

hips

Blackdisney315 4 months ago updated by Peter - Soxware Developer 3 months ago 5

This asset is what i thought it would be. extremely easy to use and set up and makes animation a breeze. The only thing thats missing is IK for the Hips /Pelvis. I did the whole ik pinning for the feet but what about the spine? every time i adjust the hips I have to adust the spines neck and head too. Why isn't there ik for the hips? I want that. I need that. its an important part of my animation techniques,

UMotion Version:
Version 1.26(current)
Unity Version:
Version 1.26(current)

Answer

Answer
Answered

Hi,

thank you very much for your support request.


The UMotion IK constraint can be used on any type of bones. It's just that the IK setup wizard does not create IK for the spine. You can add IK to your spine manually.

Please watch the IK video tutorial to learn how IK constraints can be setup manually (first part of the video covers the IK setup wizard, second part the manual setup):


I personally prefer using FK for the spine though. When you select all the spine bones and use the rotation tool, the rotation is automatically smoothly distributed between all selected bones. That creates a really smooth bending while still maintaining full control over each and every individual bone (due to FK), something you loose when using IK instead.

Please let me know in case you have any follow-up questions.


Best regards,

Peter

Answer
Answered

Hi,

thank you very much for your support request.


The UMotion IK constraint can be used on any type of bones. It's just that the IK setup wizard does not create IK for the spine. You can add IK to your spine manually.

Please watch the IK video tutorial to learn how IK constraints can be setup manually (first part of the video covers the IK setup wizard, second part the manual setup):


I personally prefer using FK for the spine though. When you select all the spine bones and use the rotation tool, the rotation is automatically smoothly distributed between all selected bones. That creates a really smooth bending while still maintaining full control over each and every individual bone (due to FK), something you loose when using IK instead.

Please let me know in case you have any follow-up questions.


Best regards,

Peter

Thanks for the reply but i still can't get it to work the way i want it to. If you ever used a blender rig then you know what i'm talking about. The hips move freely from the spine but you can still control most of the body like for crouching ect... When u set up Inverse Kinematics for the hips/ pelvis, what do you set as a target? do you use anything for the pole target? what chain length and any other settings do u use to make it work.

Unfortunately I'm not that much into blender so I'm not familiar with the specific rig that you're mentioning. Can you show me a video that demonstrates what you are trying to achieve?

If you pin the feet in UMotion, you can freely move the hips with the feet staying in place. The upper body is moving with the hips anyway (as the spine is a child of the hips).


If you want your shoulder/upperbody to stay in place while moving the hips, you would setup an IK chain from the hips to the start of the neck. Then you would activate IK pinning on the neck IK handle. That way moving the hips keeps the shoulders in place. Is that what you're trying to achieve?


Best regards,
Peter

yes. to make the upper body not inherit the rotations of the hips. so the hips rotate freely

Yes this is possible by using IK on the spine. Here is a quick guide how to set it up. Below is a screenshot that shows the names of all the spine bones of my character for reference:

  1. Go to config mode and open the IK setup wizard.
  2. Follow the instructions of the first dialog window (where you have to calibrate the forward-facing direction of your character).
  3. Then we are going to add a custom IK chain for the spine by clicking on “Add Custom IK”. I used the following settings:(click to enlarge)

    What this does is it set's up an IK constraint that is controlling the bone named "Spine". Combined with IK pinning, this decouples the spine's rotation from the hips rotation (more on that later)

  4. Click on Create. Go back into pose mode.

  5. Under Display --> Rig Layers --> enable IK. This makes it easier to see the relevant things.

  6. Whenever you now want your upper body to stay in place, select the spine’s IK handle (the wire cube) and set “FK/IK Blend” to 1 and enable “IK Pinned”.
    If you now rotate the hips bone, the upper body stays in place.

    (I changed bone style to "stick" to better see the hips rotation)

    PS: You can use the pole target (see previous picture) to rotate the bone named “Spine” in my case (i.e. the bone controlled by the IK algorithm.

I hope this get’s you started. You can also setup the IK chain in other ways depending on your exact use case. Feel free to play around with different setups. All the details about the IK constraint can be found in this video tutorial:

Please let me know in case you have any follow-up questions.

Best regards,
Peter