Adding a new scene component to a blueprint doesn't replace default scene root, breaks collision detection

Paul_Jura · June 24, 2015, 2:31am

I was following tutorial on custom projectiles (https://www…com/watch?v=pdjFm7YA8vI) and ran into trouble when my projectile was falling through world, despite following directions exactly.

I noticed :

It says default scene root should be replaced by a new scene component, which does not happen. (By way, in tutorial video, which is based on 4.7, default scene root was replaced automatically)

isn’t a problem for most things, movement and rotation still works, particle effect still works, but collisions do not work at all.

If I move box to scene root, then suddenly collisions will work:

anonymous_user_33800a51 · June 24, 2015, 7:52pm

Hi Paul,

Thanks for report! It appears tooltip for DefaultSceneComponent was not updated to reflect new behavior in 4.8, in which DefaultSceneRoot is not automatically replaced by newly added components. I have created a bug report to have tooltip adjusted (UE-17622).

In instance of specific tutorial (which was created for 4.7, in which behavior had not changed and tooltip was correct), making your box collision component root solves issue because both ProjectileMovement and RotatingMovement expect a root with collision.

If I see an update on bug or if developers decide to change behavior of component tree in regards to how new components are added, I will update post. Thanks again!

adelmo83_1 · July 29, 2015, 5:37am

Now I have same makeshift, but solution is dragging box collision on DefaultSceneRoot and ready!!!

cr125rider · September 15, 2015, 2:40am

seems to be breaking tutorial: “Working with Components on Actors Part 1” too.

anonymous_user_33800a51 · September 15, 2015, 2:29pm

Hi ,

was fixed for 4.9. Are you using 4.9 or an earlier version of editor? Can you link us to tutorial you’re following, please? Thanks!

anonymous_user_62aeda94 · September 23, 2015, 11:36pm

is also broken in 4.9 as well under same tutorials (“Working with Components on Actors Part 1”). After adding empty actor to a new, default level, and are instructed to add “cone” component you get an “Uh…Ohhh” message and tutorial will not go any further other than say to re-add DefaultSceneRoot, which is actually still there. When cone was added and renamed to Base, it was given a location directly under DefaultSceneRoot Scene.

anonymous_user_33800a51 · September 24, 2015, 1:35pm

Please link me to tutorial and I can enter a ticket for docs team to update it.

anonymous_user_650f1d25 · October 26, 2015, 6:51am

Here’s a vid I made of tutorial exhibiting problem zrocweb is talking about. It’s an in-editor tutorial so I don’t think it’s possible to link.

(Fresh Empty project using 4.9.2.)

anonymous_user_33800a51 · October 26, 2015, 5:37pm

Ah, I apologize, I didn’t realize you were referring to an in-editor tutorial. I have verified tutorial hasn’t been updated to reflect new behavior, and entered a documentation bug report (UEDOC-2607). We’ll post here when we see an update. Thanks for clarification!