The model is divided into two parts, and you can see that the light and dark are separated in the figure. In fact, these two parts use the same material, under the same lighting environment, they should have the same appearance effect under normal circumstances (the effect of the model is consistent in 3dmax rendering, and the effect is separated after using datasmith to import UE5.5), which actually shows inconsistent light and shade (depth). Does anyone know the cause and the solution?
Hi @Homes_Lu! This lighting inconsistency is often caused by differences in normals, smoothing groups, or lightmap UVs, even if the material and lighting setup are identical.
Here’s what you can try:
- Check smoothing groups and normals in 3ds Max apply a “Normal” modifier or unify smoothing before exporting.
- In Unreal, verify if both meshes have valid lightmap UVs (Channel 1) and matching tangent space.
- Ensure both parts have the same scale/transform and Nanite settings, as differences can affect shading.
- Try combining both parts into a single mesh in Max and export again to see if the issue goes away.
I am leaving you some documentation that may be helpful.
If you’re still facing challenges or have new questions, feel free to share.