ZecMurphy
Community Assistant
LOD was technically a requirement since Trainz 1.0... Just it automatically handled it, or have we forgotten about the 'progressive mesh' system
TRS2004 then introduced the 'index mesh' files, along with the 'lm.txt' file for LOD. However little to no 3rd party content initially used it, and only a very small number of creators actively adopted it for traincar assets (scenery was still often low poly, with short draw distances and smaller layouts, enough that it wasn't as big a concern - high poly scenery should still have had it, and some did). But just because the community didn't use it, doesn't mean it wasn't necessary. I look back and seriously wonder how much better Trainz could have been if 3rd party content had been a lot more efficient than it was...
But yes, LOD was a requirement under Jet. It just wasn't enforced. Actually, very little was enforced under TRS2004. TRS2006 told you something was wrong if the content had issues, but that was it. TS2009/TS2010 both enforced the rules for content (stopped faulty content from working), unless you told it not to enforce it. TS12 enforced rules fully, no option to ignore it, but it didn't report lack of LOD too well (SP1 will give you a warning, but that's about it). TANE now enforces the LOD rules quite fully, with further improvements as we move forward.
The biggest issue when talking about LOD is that you don't see any difference when you put LOD on just 1 item in a scene. It only makes a noticeable difference when everything, or at least the majority, has an efficient (or at least relatively efficient) LOD. Essentially with no LOD, you're going to be working with either the lowest possible detail, or the lowest possible performance. LOD will allow both to improve, so long as everything has it...
Funny enough, Marl's payware PS4 has LOD... Most creators make the LOD last, so beta versions will normally lack LOD until towards the end of development.
Regards