Actor moving along spline changes speed when it hits a different spline point. This is driving me nuts- please help!

Development Programming & Scripting Blueprint
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Video: Unreal Engine - inconsistent actor movement speed along spline - YouTube

Blueprint - method 1: Move actor along spline posted by anonymous | blueprintUE | PasteBin For Unreal Engine

Blueprint - method 2: Move actor along spline - timeline method posted by anonymous | blueprintUE | PasteBin For Unreal Engine

Using UE5. I am procedurally generating spline points for a train track and trying to move an object along that track. For some reason, the actor’s movement speed seems to change at two points:

  1. At the spline point immediately after a curve

  2. A ‘jump’ forward on the second spline point after a curve

It also may speed up during the curve? It’s hard to tell.

I can’t figure this out and it’s driving me nuts. I’ve tried both the distance and timeline methods of movement and both have the exact same behavior. I can’t think the manner of how I’m generating the spline points would make a difference in this because the movement is based on the length of the spline.

Any ideas? I’m open to literally anything at this point, I have spent too much time on this.

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I found a way around this and wanted to document it for any future readers.

So I couldn’t directly solve this issue. I think it has something to do with how unreal engine determines the lengths of spline curves/sections.

What I wound up doing was traversing the procedurally generated spline and dropping a new spline point into a different spline after a certain distance. This new spline was then basically a higher resolution replica in which every segment is approximately the same length. There is no noticeable speed changes when moving an actor along it.

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In case it might help, try this for constant speed along spline:

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image2404×1008 414 KB

AlongSpline

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Example of Spline Duration + Constant Velocity - it’s just a tickbox:

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