Full IK Body in VR with Unreal Engine 5.0.3

Hello. I am a newbie with Unreal and I am certainly doing countless things wrong. I created a full body IK for a Character VR. I am using Unreal Engine 5.0.3. I know, it’s still an unreliable version for VR. For example, the “Reset Orientation And Position” node does not work with the OpenXR and OculusVR plugins. With Steam VR plugin and OpenXR enabled “Reset Orientation And Position” works but motion inputs doesn’t. I am waiting for version 5.1 hoping that the problems with VR will be solved. But that’s not the problem. I am trying to use the Full Body IK node in a Control Rig, on a VR character imported from Mixamo so that when the headset is lowered the character folds his legs. I will insert some pictures to explain better. In the Control Rig Editor, of course, everything works as it should: by lowering the Head Control the legs bend as they should.

In the “Full Body IK” node I also excluded the bones of the spinal column, in order to transfer the movement of the head directly to the Pelvis bone. The Mixamo character responds well and has no problems. In the Anim Blueprint Editor in the Anim Graph tab I inserted the “Control Rig” node and in its input I selected the Head Control created to control the head bone.

Then I created a Transform variable that receives through the node “Cast To” and “Get World Transform” the movement coordinates from my Camera (FollowCamera), which is a child of a Scene Component and is the representation of my HMD in the blueprint of the my Character (Character Class). FollowCamera and VROrigin have Location coordinates “0”. I am using Oculus Rift as HMD. The problem is that my character’s head remains bound to the ground and does not align, in height, with the coordinates of my headset.

I would like to know why my character’s head always stays at ground level.


1 Like

Update: in the Get World Transform node I splitted the values in order to create a correspondence between the axes of the character and those of the camera. Let me explain: the VR Camera has for example the “Z” axis for the height. The Character has the Y axis for height, negative. I then connected the Z axis in Get World Transform to the variable of type “Transform” called “Headset”, in its Y axis, after having multiplied by -1, in order to make the coordinates negative. I also found that by moving the “Character” component in the Character Blueprint, trying to align it with the VR Camera, I can align the character’s head with the headset. I will continue with the tests these days.

Hi, did you manage to make this work? We are running into a similar issue with 5.0.3

Hey, did you ever manage to fix this? I’m currently facing the same issue on UE 5.2.

Hi and sorry if I answer you now but I abandoned the project entirely and I’m only now picking it up again. Some time ago I resigned myself to using the splendid 5.3 Patch Notes – VR Expansion Plugin and this other plugin https://www.youtube.com/watch?v=9aa0NOZPl8I. I haven’t tested anything. I don’t know if there is currently anything more user friendly. I’m studying everything from scratch, starting from the basic documentation of Meta and the official Unreal website. The problem is that many things have never been updated and there are inconsistencies there too.