Fullbody IK Goal rotation does not affect the bone chain

Hello,

I’ve been trying to figure this out for days but without any luck. I’m working on an IK rig for a robotic arm which I have made in Blender.

It all works in Blender. I set up the IK constraint, the chain behaves as it should if I move the bone that has the constraint on it. I need to also have the rotation/ orientation of this bone affect the chain(for approaching objects with the robotic arm) - and there’s an option for that in Blender: under the IK Constrant tab you define a Target(e.g.: an empty outside of the armature in the ViewLayer hierarchy - that’s what Blender creates by default) and to check the box next to Rotation.

The issue is I can not get this target to be imported into Unreal Engine (5.1). Since in Blender the target needs to be (almost)any kind of object outside the Armature, it will not be inside the IK Rig in Unreal.
I have tried to create an IK Goal out of the last bone in the chain in Unreal. The IK works fine when moving the Goal, but rotating it doesn`t do anything.
I’ve checked the sample content projects and none of the characters’ IK goals seem to be working the way I need it to.

Any insight would be greatly appreciated!

Check out ContentExamples free project (in the UE Marketplace), and its IK Rig level - there is an example of the IK rig for the robotic hand which is very similar to your hand.

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I did check that level, and unfortunately it doesn`t work the way real robots do. Rotating the goal has no effect at all. Thank you for the suggestion anyway!:slight_smile:

Sharing in case anyone else runs into this issue. I managed to get in touch with one of the Epic Devs and they told me it’s not possible using the built in IK solvers. They are implemented in a simplified manner to save performance. This functionality is very specific to robotics. Working on my own C++ solver

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