BUG: SphereTraceByChannel radius cannot be larger than Character Capsule's radius

EDIT: I’ve come across a bug with the SphereTraceByChannel (and capsule and box) nodes, where a radius larger than your character’s capsule’s radius will cause the trace to reset its impact location to be the origin of the sphere, not the point of contact.

You can observe this by firing the Wall/Ledge Detect custom event on Tick from inside your Character BP (as shown below). When the radius is larger than your character’s capsule’s radius, as the character approaches an object that responds to the WallTrace custom channel, the debug contact point will be shown, however, when the character finally touches the object the contact point will shift to the sphere’s origin. This is not just cosmetic, either, you can actually see the abrupt shift in X or Y in the Print String of the Impact Point vector. This bug prevents a large spherical trace from being possible.

Thanks very much for looking into this!

-Adam

Hey,

Are you using the default template Character BPs? Like First/Third Person BP or are you using a custom one? I’m not finding this any of this in the default character bps. So if you could provide me with clarification of where you found the Wall Trace Inputs or the Custom Event that would be great. If you are using something custom or modified then I would need you to send that to me so I can investigate.

Thanks

Hi ,

Thanks for your reply. I’ve recreated it in the Third Person template. When you play the game, walk toward the rounded cube as shown in the image below. Keep an eye on the X value. Watch it shift abruptly once your character touches the cube, and the debug square also disappears (my character is much smaller than this mannequin, so I can see that the debug square is actually snapping to the origin of the sphere trace). This issue also happens with capsule and box traces as well.

I have linked to a simplified project: [https://drive.google.com/open?id=1AjyA2o8uK0D2PcU3XdW0AwFTTqdPOsem][1]

I hope this helps! Thank you for your time in looking into this.
-Adam

EDIT: Hit F1 to turn on wireframe view, and you can see the debug square snap to the origin.

MAJOR EDIT 2: I just discovered there’s nothing special about the number 27 here. Actually, that’s my character’s capsule’s radius. For the default mannequin, with a radius of 42, a radius of 43 or more on the sphere trace will break the system.

Hey,

I was able to replicate the issue. I have logged a JIRA ticket with the developers for them to address this. You can access UE-53119 at anytime to check the status of the bug.

That’s great to hear! Thank you, , for investigating the issue and reporting it.

Have a good day.
-Adam