Thanks for the photo. I see what you mean. It's a shame. I don't think that's possible in tracks (please someone tell me if I'm wrong!)
The only 3 types of animation I'm currently aware of are:
1. Dynamic Objects: for objects travelling in a constand direction and speed. The quantity and location can be slightly randomised.
e.g. (in models.ini)
[DYNAMIC_OBJECT_1]
PROBABILITY=100
MULT=5,25
FILE=swan.kn5
POS_MODE=RANDOM
RND_POS_CENTER=-5,0,0
RND_POS_RANGE=10,0,-500
VEL_MODE=RANDOM
RND_VEL_BASE=0,0,-1
RND_VEL_RANGE=0,0,0
2. ksFlags shader: for objects that sway or flap in the wind from side to side
3. stFlow shader (by Stereo)
https://www.racedepartment.com/downloads/stflow-shader.23999/ for occasions when scrolling the texture along/across the mesh will work. I'm currently working on a track that uses this technique. It can be used with an alpha channel for transparency (on the first Normal texture slot).
@Gunnar333 has used this brilliantly in Goodwood Hillclimb (
https://www.racedepartment.com/downloads/goodwood-festival-of-speed-2017.26839/) on the helicopters to make the rotor blades rotate (the mesh is a fan of quads with the texture scrolling along them), but this is rotation of a different kind to what you need I think.
4. Bonus (but still not what you're after sorry): You can use stFlow (with and without alpha transparency) and ksFlags IN a dynamic object such as
@Gunnar333 did brilliantly with his helicopter. Combined they can be quite cool!
Sorry it's not what you're after.