4.3.85: Freeze after multiple scans

General
#1

Hello Aron,

another bug I found in the newest version - it can happen that the game/editor freezes during scanning. This happens after I “loaded” a scene the second time - but not every time, and not for every scene. It just so happens exactly in this case when I enter a room twice.

(Scanning of the last room has already finished, I run that as a coroutine and only show the game when scanning is finished)

See the video… Unity somehow seems to still “run” from what I can see in the task manager… but nothing happens anymore.

Let me know what else you need to know :slight_smile:

Thanks, Greetings,
Denzi

#2

Hi

Is there anything interesting in the log?

#3

Nope, no new entries in the console when it happens… and no crash in the editor.log file…

It feels like some kind of infinite loop … game sound keeps on playing - but that does not have to say anything :smiley:

#4

Hi

Do you think you could try with 4.3.86?

#5

Hi Aron :slight_smile:

Unfortunately the new version didn’t change anything … same issue still remains…

Greetings,
Denzi

4.3.85: Navmesh Offset
#6

Can you replicate this?

#7

Checked it with 4.3.87 … no changes, same issue still appears…

I noticed that it has nothing to do with “multiple scans” but rather with specific levels… if I start the editor from these certain levels, nothing will happen but the unity editor loader “Hold on… Application.EnterPlayMode”. So it will not start these levels either.

#8

If there’s anything you could do to try to figure out why those particular levels cause a crash, that would be immensely helpful.
Or use debug mode (also disable the burst compiler) and try to pause the execution while it’s running to see where it got stuck.

1 Like
#9

Ok will try to do so … give me some time :slight_smile:

#10

Hello Aron,

took me some time to get behind what is happening… I have a script that rotates objects (like rocks etc) randomly on Start(). These GameObjects often have RecastMeshObj’s on them.

Since some versions, A* shows errors for this script, as it is not allowed to rotate “non-dynamic” objects (even if I want to rotate them only once in Start). So I developed this workaround, which worked for some time: I disable the RecastMeshObj before rotation, then re-enable it afterwards.

private void Start()
{
    var recastMeshObj = GetComponent<RecastMeshObj>();
    if (recastMeshObj != null)
    {
		recastMeshObj.enabled = false;
    }

    // HERE, RANDOM ROTATION CODE IS EXECUTED
    //  ...
    //  ...
    //  ...


    // afterwards, reset dynamic setting.
	if (recastMeshObj != null)
	{
		recastMeshObj.enabled = true;
	}
}

Then I noticed that this crashed randomly. Not in every level, but if, then it was reproducable in that level every time… I guess disabling and enabling RecastMeshObj’s does f*** up the A* pathfinding scan process in the background, or something?

In the end, I had to put the whole thing inside Awake() - that should be before the A* scanning process, at least for my setup -, and instead of disabling/enabling the RecastMeshObj, I cache the original “dynamic” value, set dynamic = true, do the random rotation, and then reset “dynamic”:

private void Awake()
{
    // cache dynamic setting and enable.
    var isDynamic = false;
    var recastMeshObj = GetComponent<RecastMeshObj>();
    if (recastMeshObj != null)
    {
        isDynamic = recastMeshObj.dynamic;
		recastMeshObj.dynamic = true;
    }

    // HERE, RANDOM ROTATION CODE IS EXECUTED
    //  ...
    //  ...
    //  ...



    // afterwards, reset dynamic setting.
	if (recastMeshObj != null)
	{
		recastMeshObj.dynamic = isDynamic;
	}
}

Problem of the “Crash-Freeze on pressing Play” fixed :slight_smile:

#11

But now the next problem shows up :slight_smile:

What I noticed is: there seems to be something like “too many RecastMeshObj’s” in a level. In my “Main Map” level, there are ~500 RecastMeshObj’s. If I try to “reload” that Main Map inside the game (meaning reload that exact Unity scene), Unity crash-freezes when I set up the A* pathfinding for the loaded scene, when I call “SnapForceBoundsToScene” for all RecastGraphs.

If I remove most of the RecastMeshObj’s and let there be ~50, the level can be re-loaded - nothing crashes anymore…

#12

I’ve managed to replicate this. It was indeed caused by having a lot of recastmeshobj components.
I’ll include a fix in the next beta update.

1 Like
#13

Aaaaand it works :+1:
Good work! Thanks :grinning:

Have some nice vacation days! Merry christmas :smiley:

1 Like