Wrong Lighting On Negative Scaled Spline Meshes

In a custom blueprint, if I multiply X size of start scale and end scale of a spline mesh by -1, it shines weird after building lighting. I was able to reproduce this on 2 different meshes & 2 different splines. They are shining different than the ones that are multiplied by +1.

Seems like normals or tangents flipped or got weird. You can create small materials to visualize normals and tangents, or even use normals view mode.
Maybe it is not a bug, if spline less than 0, then there are many weird things can happen :-\

Hi,

This sounds, as HungryDoodles stated, like the normals are flipped on your mesh. Does this occur if you use the same static mesh in the level viewport and set the scale to -1?

Hi,

We have not heard from you in several days. I am marking this as answered for tracking purposes. If you are still experiencing this error, please comment with the requested information.

Hi ,
I tried setting the scale to -1 with the same asset but in a StaticMeshActor, it recalculated normals fine. This problem only occurs on spline meshes.

Do you have an asset that I can take a look at or a sample project where this is occurring? I’ll be happy to take a look and see if I can reproduce this on my end.

Hi ,
To show you the asset, I put only needed assets to an empty level then rebuilt lighting, now problem is fixed. I think cached bad static lighting data was causing the problem. I tried to reproduce this in the new level but I was unable to do so.

I think you may mark this as resolved since I find the way to fix, just clearing static lighting cache is enough.

Here is the screenshots from old level that I just took:

After clearing the lighting cache, all surfaces are shining like the one that is resized by -1, as expected.

yea this happens for me too… its a very reproduceable problem with any static mesh… just use it in a spline mesh and in the blueprint for the spline mesh flip it -1… in normal view you will find that hte normals arent flipped like they would be with a regular static mesh that gets flipped