Edit:
SOLVED: in case anyone has the same problem, I Solved it by making my skin materials (Face, Tongue, Teeth,…) to Surface Domain, set its shading model to Subsurface profile, Applied a subsurface profile from an Imported metahuman, and above all, made the material TWO SIDED.
Then Enabling Ray-Tracing ( Directx12, Use hardware raytracing,… ) in project setting, solved the problem.
Hey. We have our project which was originally a UE4 one and we converted it to UE5. We had this problem of inside Characters Mouth were too bright in UE4, and it continued to exist in UE5 as well.
HOWEVER, I Discovered that when I created an empty UE5 Project & Turned On all Ray Tracing options and then migrated some of our characters the issue was solved,
the problem is when I Enable Ray Tracing in our original project the problem is still there & I really can’t understand what the difference between these 2 projects are.
On the left is our original project which you can see no shadows are applied inside the character mouth, and even no proper ambient occlusion is applied on the background rocks (maybe the problem resides in ambient occlusion settings?) [All Ray tracing options are on ]
On the right is our animation migrated into a new empty UE5 project with all Ray Tracing Options on. and you see it has all the correct shadows, both inside the character mouth and on the background rocks.