[Bug report] Line Trace go through landscape in a certain area at a 90° angle


Today I just solved a bug in my game by making the line trace not hit the landscape at a 90° angle.

What was happening was that when I did a line trace at a perfect 90° angle (top to bottom) in between 25000 to 25500 on the y axis on the landscape it was simply not hitting the landscape !
Here is the landscape infos
The size of the landscape is 50500 and the bug was happening ONLY between 25000 and 25500 on the y axis and ONLY at a 90° angle.

It was doing it for every line trace nodes, even multi line trace.

Also, when I made the line trace end at z -10 (the landscape was flat at z 0) it was hitting at a 90° angle between 25000 and 25500 y. But there was HUGE areas on the rest of the landscape where it was NOT hitting now !

I believe it is a bug that come from the engine.
And I made some googling and this is not the first time someone complain about sometimes not being able to hit the landscape with a line trace.

Are you using trace complex by any chance? From what I remember, this happens when using Trace Complex, as it traces against generated triangles of the Landscape (in between which there may be infinitely small gap, which can be statistically hit through though), while simple (non-complex) trace should trace against the landscape heightfield.

](filedata/fetch?id=1801376&d=1597526148) So here you can see that I don’t have the option on the landscape to choose from simple or complex collision trace.

If that is something else you meant please enlight me

He’s talking about your trace, not the landacape settings.
what line trace are you using?

At least as of .25.2 I have been consistently using a linetrace to return the tile name of the landscape for bug fixes. It’s never had an issue…

Yeah, I meant this toggle:


This toggle was already off,
So needless to say when I turn it on I have the same bug happening.

Probably because the probability of having that occur is quite low