I'm assembling a scene with a big mandala inside a 'walking labyrinth' in a hall that's 10 metres internal, so ~12 metres roof-span.

Hunted around, found a nice big truss. It was so poly-heavy, I'd have to run it through a de-polymeriser.

Hunted further, found a low-poly truss. snag was the object had two extra boxes hiding part of span.

I've had weird results from my old 2D/3D TurboCAD, but my recent acquisition of recent 2D version, which loaded an updated bunch of C-Net stuff seems to have rejuvenated it.

So, I killed off the extra boxes, managed to 'Boolean-add' all the truss sections into one object, the fixing  plates into another.

Snag was TC promptly scrambled the OBJ export...

I tried several work-arounds, finally used free UV Mapper Classic to map the truss, save template  and re-save a matching OBJ. But this now had only one (1) material zone. Some more experimenting using free Irfan View let me paint template passably.

It's not great, but it will do, and I can save a lot of resources by 'duplicating' it down the length of hall...

I'll have to check design details for truss spacing and wind bracing...

So, the truss...