So, reading through this thread, while I don't understand the technicalities of what was being discussed, I got the idea that something had been changed between previous versions of T3D, and version 10 that changed the way terrain textures are blended? That clicked with me, as I had been able to get terrain materials to look fine in previous versions, but then suddenly couldn't with 3.10 (and maybe 3.9? I don't recall).
I've always known that T3D can produce great looking terrains, and I've been playing Life is Feudal, which I'm sure uses a previous version of T3D, and that game's terrains look awesome.
So I went ahead and tried 3.8 to see if it would make a difference and, lo and behold, everything looks fine. I'm using the same textures/layers that I tried unsuccessfully to get to look acceptable in 3.10.
Here's a shot I took of my "tests" in 3.8 with a few texture layers, and a nifty decal road. The textures are nothing to scream about; was more concerned about getting them to look "right" more so than "good".
So yeah... seems fine there.
Something else did arise, though. I noticed that if I go over 3 terrain layers, that 4th layer will have a kind of "halo" around the texture, instead of blending smoothly into the layer(s) beneath it. Is this a known thing, or is there some good way of getting around that?
Anyway, I still don't think it would be a *bad* idea to introduce another option for terrain texturing and let people decide which they prefer to work with (similarly to how you allow them to choose Physics versions, etc), as per my previous posts... I think maybe reverting the "math" to how it was in 3.8 could be fine as well?