Child actor component and Template bug

[skeleton60]

Hello,
There is a bug with -child actor component-
BP_Collision is a simple blueprint that add a box or sphere collision component following a variable. I intend to use it as child actor component.

Look i have a BP_Actor in my scene that have a -child actor component- based on BP_Collision blueprint.

At this time everything look ok, the BP_Actor has a child actor component base on BP_Collision and the child actor template has the variable collision shape set to Sphere

Ok this work fine.

But now if compile the BP_Collision blueprint, here is what happen :

Wtf ? My BP_Actor blueprint now has his -child actor component- making me a BOX COLLISION instead a SPHERE !
So i go check my BP_Actor to see if my variable is still set to a sphere , and it still set to a sphere (see below). Wtf he make me a box when i compile the BP_Collision?

If i try to play my game, it still make me a box instead a sphere !!!

To get the correct shape back, i have to recompile BP_Actor again

If i compile BP_Collision, Boom my BP_Actor will have a again a BOX SHAPE instead THE SPHERE !

If i compile BP_Actor, Boom it fix it and my shape is now a sphere

You can download the zip project to play with it MEGA 

[anonymous_user_d2b909bf]

Hello ,

I was unable to reproduce this issue on our end I have a couple of questions about your issue to help me narrow down the issue you are experiencing.

1. Can you reproduce this issue in a new project?
2. If so, could you provide a detailed list of steps so that I can reproduce this issue on our end?

Thanks!

[skeleton60]

yes i can reproduce this here is step by step how to do it and the project zip if needed

MEGA

1- Launch unreal engine 4.17.0

2- Create a new project based on this settings (Blueprint only, Blank template, Desktop / Console - Maximum Quality - No Starter Content)

3- Create a new Blueprint Class based on Actor, name it “BP_Parent”

4- Create a second Blueprint Class based on Actor, name it “BP_Child”

5- Open “BP_Child” Blueprint

6- Add a boolean variable named “isChecked?”

7- In the Event Graph: Plug into the ‘execution Pin’ of BeginPlay a ‘Print String’ to display ‘isChecked?’ value on screen

8- Compile and save “BP_Child” blueprint

9- Open “BP_Parent” Blueprint

10- Add A Child Actor component to it by doing a Drag and Drop of “BP_Child” into “BP_Parent” component attached to the DefaultSceneRoot

11- Select Child Actor component and in the Details panel expand the ‘Child Actor Template’ category, expand the ‘Default’ category and
check to true the boolean ‘IsChecked?’

12- Compile and save “BP_Parent”

13 -Place “BP_Parent” in your world level

14- Hit play

The print string display “True” that is ok at this time! End play

Steps to reproduce bug:

15- Open “BP_Child”

16- Compile and save it

17- Hit play

and it display “false” and it should display True !

Note: if you compile BP_Parent before play you will get “True” on screen, if you compile BP_Child before play you will get “False” on screen

it mean our game wont run the same depending on the compilation order :x

[anonymous_user_d2b909bf]

Hello again ,

I was able to reproduce your issue with the repro steps you provided. I have logged a report for this issue which you can view here:

The Unreal Engine Issues and Bug Tracker

You can track the report’s status as the issue is reviewed by our development staff. Please be aware that this issue may not be prioritized or fixed soon.

[skeleton60]

Thanks,

i found a new behavior to get the good expected value, that may help to debug this: if you move the “BP_Parent” a bit in the scene before hit play (translate it along x axe for example) then it will display the good value

so we have two way to get good value:

-Compiling BP_Parent before hit play
or
-Move a bit BP_Parent in the scene before hit play

Note that in my step by step project i gave u, it is a bug about variable, but there others bug with component added that i didnt explain here.

It is important to note that: in my game project where i have this bug, it seem that the solution of moving a bit my blueprint in the scene, before hit play, fix it better than compiling it

i dont know why but components and variables work fine when i move a bit my blueprint in scene before hit play.

if i use the compilation solution before hit play only variables seem to be fixed but components have somes bugs

i hope you put this in a high priority bug to fix because we cant use child actors at this time