PBR-based asset messy with Ultra shader level

Hi Guys,

I'm working hard on my assets in a Blender + Substance combo. The results look damn good in Blender, Substance Painter and AutoDesk FBX Viewer. They also look good in Trainz when Shader is set to Standard level. However when I switch to Ultra level, things get messy, and I can't even phrase the phenomenon properly, but it's like normals were flipped to a wrong direction or surfaces would bend or IDK. A picture is worth a thousand words, so here they come.

A few object of mine at Standard shader level: https://drive.google.com/file/d/1QiF8tyZILzCgIQZGZorg0QigKnylGgKP/view?usp=sharing
+ See it rotating around: https://drive.google.com/file/d/1qym7O8g-B4Mni0YaZ868CRmwaVxRPHK_/view?usp=sharing

The same objects with Ultra shader level: https://drive.google.com/file/d/1R4wHNbbcbLs6WGjnwzQezyJn-85DNB_u/view?usp=sharing
+ See it rotating around: https://drive.google.com/file/d/19Z4BptzbT5lzomjxKbeFMJgmUFDUr36R/view?usp=sharing

Can you, please, advise how can I get rid of these noises? (Hopefully without the need to remodel and repaint everything...) Also, if you know the background why it goes this wrong, I'd be interested in learning the theory/concepts.

Cheers,
T1nker/Gus

With PBR you need to drop the shader level to standard. If you use ultra, you will always have conflict between PBR and non PBR causing ghosting especially through splines.

Yep, I know PBR and non-PBR conflicts, but my case is about my two assets, fully PBR, and the issue is not that they conflict with others, but that they appear wrong. I'd like to make it work with ultra shader so that others using Trainz with that setting regularly can also enjoy my productions.

Remove alpha line from normal.texture.txt

Oh well, 5511 #phong4460 on Discord came up with the solution: if I remove the Alpha=<normal-texture.jpg> line from the normal map's texture.txt file, it's perfect. Dunno yet why, but if someone explains it, I'd be happy, and I'll share the answer here if I receive it elsewhere.

Thanks! I'll need to dive into that topic. At least I could saw how it unintentionally works.