Metahuman Groom Warning

Development Character & Animation
1

When creating a metahuman and I hit “Create Full Rig “ , I get the following warning al the time. What does it mean?

LogHairStrands: Warning: [Groom] Binding asset will not respect the requested ‘Matching material’ 8 for LOD 2. The target skeletal mesh does not have such a material for this LOD. Instead material 0 will be used for this given LOD.
LogHairStrands: Warning: [Groom] Binding asset will not respect the requested ‘Matching material’ 8 for LOD 3. The target skeletal mesh does not have such a material for this LOD. Instead material 0 will be used for this given LOD.
LogHairStrands: Warning: [Groom] Binding asset will not respect the requested ‘Matching material’ 8 for LOD 4. The target skeletal mesh does not have such a material for this LOD. Instead material 0 will be used for this given LOD.
LogHairStrands: Warning: [Groom] Binding asset will not respect the requested ‘Matching material’ 8 for LOD 5. The target skeletal mesh does not have such a material for this LOD. Instead material 0 will be used for this given LOD.
LogHairStrands: Warning: [Groom] Binding asset will not respect the requested ‘Matching material’ 8 for LOD 6. The target skeletal mesh does not have such a material for this LOD. Instead material 0 will be used for this given LOD.
LogHairStrands: Warning: [Groom] Binding asset will not respect the requested ‘Matching material’ 8 for LOD 7. The target skeletal mesh does not have such a material for this LOD. Instead material 0 will be used for this given LOD.

2

Hello there @unix0unix!

Checking around the community, that warning is tied to your hair material, and how it’s assigned between different LOD levels in your rig. Each groom has binding data per LOD, which tries to match with the Material ID. Since it’s asking for slot 8, it means your mesh has fewer slots assigned. And the result is defaulting to Material slot 0 (usually the base skin).

This is expected behaviour, and the warning is simply informing on the fact, it shouldn’t give you any problems. Still, if you prefer to not have this warning, the solution is fairly simple, manualy matching the material ID mappings to a corresponding slot. You can also increate the ammount of material slots, so each LOD can have it’s corresponding entry.

For further reading on the subject, please check UE’s documentation about Metahuman groom: