Timeline in C++ triggers breakpoint

Katianie · January 21, 2018, 9:18pm

I have been following these two links to try and get Timelines to work in C++:

[A new, community-hosted Unreal Engine Wiki - Announcements - Unreal Engine Forums][1]
[How to create a Timeline in C++? - Programming & Scripting - Unreal Engine Forums][2]

I tried both UTimelineComponent and FTimeline but both ways are triggering a break point when I try to play. Here is a screen shot of the error:

Edit: I tried initializing the timeline and curve in both the BeginPlay function and the constructor but to the same results.

xlar8or · January 21, 2018, 10:00pm

Hey there, you need to see what is the actual cause of the crash, check the Autos tab to see if anything is invalid (especially check the this variable, myDoorRotateComponent and myResetRotationTimeline).

xlar8or · January 21, 2018, 10:11pm

Usually crashes like this are from accessing an invalid object, just confirm that that is the case to know how to proceed.

vr_marco · January 21, 2018, 10:07pm

Can you tell which exception is being thrown?

Katianie · January 21, 2018, 10:07pm

Why would it be invalid? I followed the previous tutorials and none of them mentioned this issue. Should I be initializing it by calling initialize component? Because that did not work either

Katianie · January 21, 2018, 10:23pm

All I’m getting is what you see with the triggered break point. I tried it again with UTimelineComponent and here is where it triggered a breakpoint: https://i.imgur.com/NjWCLL6.png

Katianie · January 21, 2018, 10:24pm

Doesn’t look like an exception per-say, just triggers break point.

xlar8or · January 22, 2018, 12:12am

Ok so it seems your timeline is set to null. To confirm you can comment the PlayFromStart command and see if it doesnt crash. If that doesn’t crash then it confirms that the problem is indeed in the timeline. When you defined the timeline did you set it to UPROPERTY()?

Katianie · January 22, 2018, 2:38am

Just tried to set it to UPROPERTY() but I don’t think it helped, I still got a triggered breakpoint in the create default sub object. Here is a screen shot:

xlar8or · January 22, 2018, 10:30am

Can you show me where you initialize the timeline?

Katianie · January 22, 2018, 1:28pm

Sure, Here is where I am initializing the curve and the timeline. Its in BeginPlay() :

xlar8or · January 22, 2018, 1:30pm

Does the AddInterpFloat code executes? That would mean that the timeline is still valid in the constructor.

Katianie · January 22, 2018, 4:54pm

If I use UTimelineComponent pointer, ue4 triggers a breakpoint on line 59 when I try to CreateDefaultSubobject. If I change it to use FTimeline object, it compiles and runs without error, the issue I see now is that the object is not calling the update function I provided (ResetRotationTimelineUpdateCallback).

xlar8or · January 23, 2018, 12:00pm

When you say triggers breakpoint on line 59, you mean crash?

Katianie · January 24, 2018, 4:34pm

I mean what you see in the first image.