I've never seen or experienced this one before, I don't think anyone else has either to be honest as I can't see anything online about it.
My signal model has forever been plagued by a strange lighting error that seems to only occur on every other export of the blueprints. As you can probably see in the below screenshot, the arm is totally unlit aside from the white band, which is incredibly bright, but the post (which is the parent model, the arm is a child) is lighted properly. This only seems to happen on the TrainBumpSpecEnvMask.fx shader, but I can strangely fix the issue by re-exporting the same data, yet if I was to export it again I'd end up with the same issue. This has happened to the post model too, but for some reason I'm not getting the issue with it much anymore.
I haven't modified the shader's settings much from the default, but I have set the 1st UV argument to 7 for a loose phong highlight, with a specular level of 2.
I'd like to know if anyone has ever heard of this problem before, it's very odd as it appears as if the object is reverse lit, you can see the sun through the model if you position yourself in between the model and the sun itself, plus the specular shine starts to appear the closer you move to a parallel position to the model.
Anyway, interested to hear what others have to say on the matter!
Thanks,
Kevin