@remorhaz That’s brilliant, thanks for this.
Did your re-implement your own tangent generator?
This issue has to be addressed as baking normals from a high poly mesh is the industry standard now. This is one of the biggest flaws of the engine IMO.
I think we should just export the tangent along with the model. The blend file as them, and the ogre exporter can export them too.
For obj we would still use the generator though so it has to be as good as possible.
Any chance you contribute back your changes?