Hello,

I am experiencing unnatural changes in the tint of models imported on Unreal Engine 5 and would like to seek support.

The model is created from a 3D scan image of a face using CC4 and Headshot and exported as an FBX.

When importing the FBX into UE5 using Auto Character Setup for Unreal Engine 5, I am experiencing an issue where the tint of some facial parts changes extremely unnaturally under certain lighting conditions.

Specifically, only the eyes and mouth area appear strongly reddened and look as if they have cried and swollen.

When placed on a map of MetaHuman Lighting presets MHC_LightingPreset_Portrait_RT (I think this is one of the most standard lighting) or MHC_LightingPreset_Moonlight_RT, the effect of lighting becomes noticeable.

MHC_LightingPreset_Portrait_RT:

This problem occurs only in models created using headshot, not in other CC4 sample models.

I have followed the official tutorial here for generating models from 3D scans with Headshot.

- Generate the model by setting the texture of the scan data in Diffuse according to the Headshot tutorial.

- Export the generated model from CC4 to FBX format for Unreal

- Import the FBX using Auto Character Setup in Unreal Engine and place it on the lighting preset in MetaHuman Lighting

I looked at the exported FBX textures and found an image with red around the eyes, but I am not sure if this is related or not. (In UE, not only around the eyes, but also around the mouth is red).

I have also found that on UE, if I turn off the "Cast Shadow" setting for the lights hitting the face, this redness disappears for some reason.

Cast Shadow: True

It appears that there is an SSS(Subsurface Scattering) related anomaly as the symptoms change with lighting intensity. Since the exported FBX does not contain a map for SSS, I suspect that this is an issue during import by Auto Setup for Unreal.

Is this problem a glitch in CC4 or Auto Character Setup? Is it possible to solve this problem by adjusting the model?

I have uploaded the CC4 project to Google Drive here.

Character Creator 4.4.2509.1

Unreal Engine 5.2.1