Just to be clear on that: Doing what they did in the example will just add UVs to your mesh but they won't fit any unwrap you might have done for those meshes. As long as you don't use textures or when it's not important that they don't fit on the triangles, you'll be fine

Ah I should have been more precise (and that script reference has been my daily bible this past year or more!). I would like to generate something of a default projection, such that any given face will have one 'tile' stretched across it (any direction, but not distorted). Or even better, if all faces had the same sized tile. Like if I'm importing a building with a brick texture, that those bricks would tile across all faces where uv's are undefined. I imagine this would entail a) getting the extents (bounds) of each face, b) (optional) determine tile size, c) generate uv per vertex, (more..)

probably aligning to either local or world x/z plane, or first segment on the face.

hmm you talk about buildings with simple geometry? If your faces are always quads (2 triangles) you could calculate the uvs according to the position of the vertices on the face-plane, but when you have unorderd triangles it's getting difficult. As long as your building is aligned to the 3 axis (parallel to the axis) you could try what you've just mentioned. Kinda project the geometry onto your texture to get the uvs ;)

Yeah, that's what I was thinking. Simple case of a unit cube aligned to world axes, trivial. Same cube, rotated, there must be a simple transform I could use to get those UV's. On a non-unit cube, I'd be scaling the UV's according to the size of the bounding square in the plane of the triangle. I was hoping there was some handy utility for this, but if it needs to be written, by golly, that's what I'll do (I actually did something similar years ago for an Unreal Editor exporter)