Disclaimer: this question is, by the moment, more oriented to a mental experiment than to an actual custom creation project, that could change depending on the difficulty of the task.
With the advent of the much more realist L1 (7.5 metres high) viaducts for almost every network in game, several objects tailored to match the old L2 (15 metres high) viaducts are becoming obsolete, or at least, less flexible to apply. Nevertheless, many of them are really great works of modelling and it would be a shame to get rid of them.
At the same time, there exist the capacity to modify the scale of S3D models with the Model Tweaker, which has been used to solve general problems of uneven scalling after the models had been rendered.
The question is: is the model tweaker able to re-scale an S3D model on only one axis (specifically, the vertical or z axis), to make objects as Deadwoods' Raised Parks, SFBT Urban Highways and Morifari El-rail enbankments to match the new L1 standard? While this would be a solution of less quality (as compared with creating new versions of those models, using the most recent advances in modelling), it would reduce enormously the workload and time to achieve compatibility.
And just as important: which would be the sharing statute of the resized models? I understand that the modification is done to the model itself, creator side, and the original SC4model files couldn't be refered as a dependency. There could be, then, a fair way to redistribute the hypotetical scaled models, particularly in the case the creators or their custodians cannot be reached to ask for permisson?
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EDIT: As I should thought, the answer can basically be resumed as "go and try it by yourself". It seems to work, or at least that's what can be seen when comparing the modified S3D files on the reader:
Yes, there is some distorsion, particularly Moiré patterns on the stairs and the rocks look a little squished, but in general the model even looks more realistic in its proportions. Don't know if the modifications will sustain on the game, and I imagine that this changes will require relotting all the objects that were put on the raised levels --and that by now have to be floating-- but that's not hard to do.
But the other question stills: If I do this resizing, would I be able to redistribute the models, license-wise? Frankly, I wouldn't be motivated to do this work if I would be the only one able to use it...