LiveLink V4.2.0 Issue with Bone Rotations

When using ZED Livelink for Unreal with the mono camera, an issue arises during arm rotation. After completing a full rotation with my right arm, I attempt to replicate the same motion with my left arm. However, the bone rotation is locked in a backward position, preventing a proper replication of the movement. The only workaround is to rotate the arm forward again.

Notably, this issue does not occur when using the ZED plugin version for Unreal. Upon comparing the codebases, it appears that the Livelink version employs the retrieveBodies function, whereas the plugin version uses sl_retrieve_bodies. I am uncertain about the underlying differences between these functions.

I have already experimented with modifying the depth mode, confidence, and other configuration parameters, but these adjustments did not resolve the issue.

Video demonstrating the issue: Issue.mp4 - Google Drive

Hi,

This is unfortunately a known issue of the current body tracking implementation. In some cases, it wrongly estimates the arm rotation and gets stuck in this configuration.

Using live link or the Unreal plugin should not matter. However, this can happen more frequently when using certain settings, for example, it should be more frequent with the Body 34 model than with the body 38.

Stereolabs Support