Spline modified in BP can't be edited in editor afterwards

Development Programming & Scripting Blueprint
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If I have a blueprint with a spline component and drag it into the editor, I am free to add more spline points and manipulate them.

However, if I modify the spline in the construction editor first - e.g. by adding a single point, and then drag it into the editor, the spline is a pink colour and cannot be manipulated at all.

Is this deliberate behaviour / a limitation at the moment? Or am I doing something wrong.

I’ve noticed user jayice also describing this behaviour in 4.9 in this thread right at the bottom which sounds pretty suspect https://answers.unrealengine.com/questions/242516/480-splinecomponent-set-world-location-at-spline-p.html

2

Hi,

I’ve just come accross this issue myself, though I am working with C++ and not Blueprints. The UE4 Editor only allows splines to be edited if they have either been edited before, or the points in the spline are the default points.

This line from SplineComponentVisualizer.cpp explains that:

const bool bIsSplineEditable = SplineComp->bSplineHasBeenEdited || SplineComp->SplineInfo.Points == Archetype->SplineInfo.Points;

I was able to make my Splines editable again by setting bSplineHasBeenEdited to true after adding my points. I am unsure if you can do that within a Blueprint, but hopefully that can help you.

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3

Sadly that boolean isn’t editable in Blueprint, although I can see it. Luckily my project will be in c++ - i’m just prototyping in Blueprint.

Quite bizarre behaviour - it’d be great if someone from Epic would chime in on this (whether it be working as intended, or a bug)

Thanks for the workaround - i’ll use it once I convert my BP to code!

4

You could write a very basic blueprint library function in c++ that took a spline component and set the boolean to true.
It does work and solved my issue!

6

I checked Override Construction Script on the Spline and that seems to make it editable again. I have one end that snaps to another object, and that was locking me out.

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