MetaHuman Groom hair simulates in BP/asset preview, but not in Play (PIE/runtime)

Development Rendering
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1

Hi,

I’m having an issue with MetaHuman Groom (strand hair) simulation in UE 5.6.

What happens:

  • Groom hair simulates correctly in:
    • Groom Asset Editor
    • Character Blueprint viewport
  • As soon as I press Play (PIE), the hair stops simulating and becomes static.
  • Character animation plays normally, only the groom simulation is frozen.

Environment:

  • Unreal Engine 5.6
  • Windows PC
  • Deferred Renderer (Forward Shading OFF)
  • MetaHuman with default strand-based Groom hair

What I checked/tried:

  • CVars in PIE console:
    • r.HairStrands.Enable = 1
    • r.HairStrands.Strands = 1
    • r.HairStrands.Simulation = 1
  • Scalability set to Epic (sg.EffectsQuality 4)
  • Groom physics and Chaos simulation enabled in the Groom Asset
  • Forced simulation ON at BeginPlay (with delay)
  • Disabled update rate optimizations, set Always Tick, Post Physics tick group
  • Hair LOD logic (Is Hair Strands Supported in World) does not seem to be the issue

Expected behavior:
Groom hair should simulate at runtime the same way it does in editor and BP preview.

Question:
Is this a known limitation or bug in UE 5.6, where Groom/Chaos hair simulation does not run in PIE/runtime but only in editor/preview or Sequencer?

Any insight would be appreciated. Thanks!

2

Solved., I have struggled for hours and the issue it was only:

LOD switching caused by the Third Person Camera distance

At runtime, the spring arm was far enough that the character switched the LOD, where the MetaHuman hair is no longer cinematic / simulated. After reducing the Third Person Camera (Spring Arm) distance, the character stayed on LOD 0 and groom simulation worked correctly in PIE.