Cool track wip, it needs its own thread.
I agree pixel pusher on ACs shaders stopping fun/creativity.
I wrote a nice shader for Racer, for 'roads' which had a wear map and base maps, and asphalt 'grain' scale, so you could do most uk asphalt styles in relatively low res (256px wide for road) and literally unwrap uniquely over km of road for near infinite variation.
So smoothed down bits, newly laid stuff, coloured rough bits at roundabouts etc.
Throw in vert colours and you could do loads more.
On night time looks, can you bake vert lighting yet? Lightmapping?
Without those you're stuck baking lighting into diffuse with lots of unique or well lined up textures, and well calibrated 'emission'
Unless emission can be mapped into a spare channel with some shaders?
A shame AC stopped with their renderer features just as it got going.
Sunny fine day, great. Anything else (like average uk weather haha) not so great.
Is current AC shading full fresnel and pbr, or a bit hybrid?
Shouldn't it be pretty easy to get 'right' results by using real values, assuming their sun/sky values are good?
On trees, usually just rotating a 3D one two or three times to get 'nice' angles is enough for normal variation to hide repeating with 2D x trees imo.
Scaling you can push them 15% each way.
So a 5 12 and 20m oak with two or three variants each should do for your oaks for example.
I did two big 8x8 atlases for x trees for s project, 4096px square, so 512px each.
The track had maybe 30,000 trees, most placed accurately and where required specifically to match real ones... so more than enough variety to get the 'look' in that kinda atlas size.
I rendered my trees with skylight only, since the 'sphere' normals and diffuse light do your diffuse influence.
I did however add a specular only light to get some glint off leaves.
I tried doing normal maps and ao so map on alpha which looked very nice, but ideally you'd go 2.5d on trees that important with normal mapped 'boughs' any way.
Can you atlas trees in AC? I never looked.
Or vert colouring for subtle variation?
Or vert/uv waving to simulate slight movement?
Not looked at AC properly for a bit so not sure if these got added or not.
My issue with AC 'greenery' was it was so static and 'paused'. Any video looks terribly fake from a static camera.
Anyhow, the track looks good.
The trees look nice from Speedtree too.
In the end I decided photo sourced 2.5d would be the best.
Get pic of typical tree you need (often uk roadside ones are heavily asymmetric and 'cut under' by the size of a lorry), redraw main branches in 3D, texture up and make look nice (possibly do all this in photogrammetry and tidy up).
Do the boughs as photogrammetry created modules. Maybe two or three variants, normal, spec, gloss.
The overhead in geometry is higher yeah, but the up close look is tons better, but the alpha checking is probably lower.
Also with 'road' courses where you're under trees a lot, or very close, the X type get a bit naff looking as you go under them.
On the track I did I'd have preferred to use the same approach but 2048 atlas and then do all nearby trees in 2.5d (2d/3D hybrid)
Just making them was impossibly time consuming... just plopping the right 2d ones off my atlas took weeks!
BUT, make good ones once and they're done forever.
I'll check something out tomorrow on my big atlas.
I *think* it's been deployed in a 'free' package so you could grab that for now for a load of uk variation, at least till you remake all the ones you need!
Remind me as I'll forget
Cheers
Dave