Download

[PSA] 4.1 Trace node bug, don't panic if your pawn freezed.

I found out today with 4.1 that if you have trace(so far only tested with MultiLineTraceByChannel and SingleLineTraceByChannel) node on a event tick line, and if your trace distance is either too short, or after moving around a while hits nothing in range, your control will freeze since it will never return when that happens.

Solution? Make a big enough box in your 3D package with normal facing inward, assign a alpha material that makes it transparent, but visible in game without casting shadow. That should do it before Epic give a fix update.
(remember to set your trace line long enough.)

Tyvm for the heads up.

Just to double check, a bug report has been filed for this right?

(I’m guessing it will only require a small code change, hopefully a fix can be pushed in a couple days tops.)

yes, I filed a bug report on AnswerHub already.

edit: I did a little dig in the source code, and it might be a bug of new PhysX.
my answerHub question is here: [BUG] Multi Line Trace By Channel never return if not hitting anything. - UE4 AnswerHub