Skip to content

nDisplay / LED Volume — Pan Values Jumping to ±3072° — Parent CineCam to Empty Actor Fix

Summary

In nDisplay LED volume setups, the CineCamera tracking data from Flair can cause pan values to jump to extreme values (±3072° or similar) when the pan angle crosses the ±180° boundary. This happens because nDisplay expects the camera's pan/yaw to be managed relative to a parent actor — if the CineCamera Actor receives absolute world-space rotations that cross the ±180° range, nDisplay's frustum calculation wraps or overflows. The fix is to parent the CineCamera Actor to an empty Actor (Scene Component), and apply the Flair tracking rotation relative to that parent rather than in world space.

Symptoms

  • LED wall frustum appears to snap or jump suddenly when camera pans past a certain angle.
  • Pan values reported in Unreal jump to large numbers (e.g., 3072°, -1024°).
  • LED wall appears correct on most moves but glitches when camera pans across the ±180° axis.
  • Issue specific to nDisplay LED volume setup; doesn't occur in regular viewport.
  • Camera tracking looks correct in the regular UE viewport but breaks in the nDisplay output.

Community Guidance

[RESOLVED] Parent CineCamera to an Empty Actor

Community consensus

The fix for nDisplay pan value overflow is to introduce an intermediate parent actor:

  1. In the Unreal scene, create an empty Actor (not a CineCamera — just a basic Actor with no mesh).
  2. Parent (attach) the CineCamera Actor to this empty actor.
  3. Configure the LiveLink Controller or OSC receiver to apply the Flair tracking transform to the empty parent actor rather than directly to the CineCamera.
  4. The CineCamera inherits the transform from the parent.
  5. This breaks the direct world-rotation link that causes nDisplay to overflow at ±180°.

Community: "Parent the CineCamera to an empty actor — this resolves the pan values jumping to ±3072° in the nDisplay frustum."

confidence_score: 0.88

Community — see CGI-freed-angle-limit.md

The FreeD protocol itself has a ±180° pan angle limit — values outside this range cannot be encoded in the FreeD packet format. This is a separate but related issue. The nDisplay pan overflow problem occurs even when FreeD is not used; it is a coordinate system wrapping issue in UE's rotation representation.

confidence_score: 0.85