Hey Paul,
I've been having a think about your idea of aliasing Allan's and my non-trackside scenery and I am having trouble understanding the reason why you would want to do so. Nearly all of our scenery assets are height adjustable and unless your ground level is at zero, as in layouts with terrain, there is usually a fair amount of fiddling required before the infrastructure all matches anyway.
However, having said that and not wanting to squash your idea. Because the assets are so simple in nature, both in complexity and poly size, it would be far easier to use the original meshes and lower the objects to the height you require, than become involved with creating extra polys underground and aliasing each item.
The reason I haven't duplicated these assets myself using different heights for the contact wire, is because, from the amount of feedback the forum has received in the past, there seems to be a multiplicity of wire heights in use amongst the community. Whilst I would be prepared to duplicate assets for your 5.3m height for example, I would not like to have to multiplicate the assets to suit all cases.
I imagined that because the the assets were height adjustable, one case would suit all. I can see that it would be far easier (providing ground level was zero on every board) to place each item at one height without the need for the extra fiddle for wire height.
Would you care to send me a personal e-mail so we can discuss your idea and reasons in more detail?
Cick on images for examples of overhead infrastructure.
Regards
Sel