Thanks Spanki,

I'm open minded on this.

I don't quite follow your statement that  "If you simply reverse the winding order of the existing vt references, they'll flip the texture around in various ways <>, but the artifact still appears." I am suggesting that any breaking of the vt winding order will cause artefacts, including reversing them, so yes I would expect reversing the winding order to create artefacts . I agree totally that reordering the vt references will flip the texture about.

I would be suprised if my fix randomly hit on a combination that worked. I do think that it would be better if I could demonstrate on a more complex geometry. I hope to try that tonight but I can't try any more experiments for about 13 hours or so whilst I am at work. I simplified the test example down to a hollow cube to make it easier for me to understand.

Currently I am suggesting that for Poser:-

a)  That the order of vt entries for each face should follow a winding order

b) And it follows that where  faces share vt entries, and smoothing is being applied across the boundary between the faces, that the winding order rule is applied for all faces including the shared vt entries .

Cheers

Ian