Sorry if this doesn't help you, but in following this conversation this does sound like something that could be fixed with an API script (and most likely a simple one at that).

I'll be SO happy when we have this possibility.

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Alienware Aurora R16, Win 11, i9-149000KF, 3.20GHz CPU, 64GB RAM, RTX 4090 (24GB), Samsung 870 Pro 8TB, Gen3 MVNe M-2 SSD, 4TBx2, 39" Alienware Widescreen Monitor
Mike "ex-genius" Kelley

Yes, if Reallusion does not fix this, we may be able to add a bit of tape with a script .. I hope ...
And I will be even happier if somebody has the idea to release a nodal editor !!!

Pixtim'Store : Motions and models (marketplace and preview)

FaceBook group : Pixtim for Reallusion Iclone and CC3

Maybe use a hinge constraint to attach your car to a dummy that follows the path? Just orient the hinge to rotate along the axis of the car.

The problem would remain the same.
If I want to get the same result that the function offers if it works, it must have two parallel splines with two dummy that are advancing at the same time. And I would have to have a double target to properly steer the vehicle. To have an automatic and perfect result, I would have to do that on both axles. But we can not have double targets with Iclone.

This is where I am with the setup of cars, but with the problem of "follow terrain", it only works if the ground is flat ...
Everything is automatic and the wheels are in physics

Pixtim'Store : Motions and models (marketplace and preview)

FaceBook group : Pixtim for Reallusion Iclone and CC3

I run into this problem now. Gosh this is so ridicules! Everything works with Following Terrain when you drag your object manually. As soon as animation kicks in - nothing works.
But I think I might know why it is not following a given terrain in animation. It actually does, but it is following an invisible - "Grid" terrain.
So there is a conflict. There should be a choice as to what terrain to follow, or the terrain should automatically be selected by the proximity.

With following a Path (projected) it does not work properly either (as Pixim already has shown). And looks like there is no entry in FT for this one.
I have a long bridge and it is a pain to setup a manual projection for the path over it.






P.S. MERRY CHRISTMAS EVERYONE!

The "project to terrain" orients all the path points exactly vertically. I think you'll have much better luck leaving it off, as then your points will orient at appropriate tangents. Try using more path points instead, if necessary.

When something is attached to a path, it is really attached! It adheres to it exactly.

EDIT:
I am only partially correct. The points still appear at their proper tangents when "project to terrain" is used, but it treats them like they are exactly vertical. The last time I used that was version 4, and it was a bit different then.

More points, is what I am trying to avoid by all means possible.
My original point was NOT to use path at all. Follow terrain works perfectly (at least in my case with lightly curved bridge), as I have shown in the first part of the video.. but ONLY when you drag the prop manually.
As soon as I set transform keyframes for the prop and start animation, a global WORLD terrain is taking over and the prop follows it. This should not be happening.

I would like to see some love given to paths. Splines could be used for all sorts of things.

The "project to terrain" looks to create a bunch of linear segments, instead of curves. The "precision" defines how many. The snapping to exactly vertical has always struck me as bug.

I think it used to interact with the terrain snapping/following in some way. It may be that originally it did that to keep avatars from tilting with the terrain when using a move command. Although the personas I have made with move commands result in the character tilting when projection is enabled. There are snap settings in the Persona that I may have set differently then the originals. Can't recall.

2 points Projected Path also work perfectly  (I mean it was developed there for a reason, right?), as I see the prop stats the rotation along with the respective curve of the terrain.
Only problem is, that it start the rotation by the perpendicular axis. It is simply tilting in a wrong direction. And that is where the programming bug is.

I am going to enter both bugs (with Follow Terrain and Projected Path into FT and see where it takes us).

Meantime I figured how to animate using Follow Terrain - by manually creating transform keys along the terrain. It is also cumbersome, But I think it is easier than creating multiple path points along the 100 meter curved bridge (the one I have in a real project).


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I'm not *quite* awake this Christmas morning (celebrating late last night) but this sounds like something that Python could manage very well (I really hope we see that this year -- it's the only thing that I think is really missing from iClone now).

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Alienware Aurora R16, Win 11, i9-149000KF, 3.20GHz CPU, 64GB RAM, RTX 4090 (24GB), Samsung 870 Pro 8TB, Gen3 MVNe M-2 SSD, 4TBx2, 39" Alienware Widescreen Monitor
Mike "ex-genius" Kelley