PhysX3PROFILE_x64.dll crash with stack trace

Development World Creation
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1

Hey Epic,

I experienced a crash in 4.13 when trying to spawn a character in the world at a spawn point I believe may be contested by a static mesh that is simulating physics (boat actor).

I was lucky to reproduce this issue with a debugger attached on my remote server running the dedicated UE4 server binary, see the attached screenshots for the stack frame.

I will try updating to UE4.14 soon to see if I can reproduce this issue there.

Let me know if there is any other information you would like for this crash!

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119582-1-physxxcrash413.png
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119584-2-physxxcrash413.png
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2

Hey Mentos,

Let me know what the result is in 4.14, but in the meantime I have a couple of questions:

  • Would you mind providing your logs for me to take a look at after the crash occurs?
  • What are you spawn settings for your character? Have you set it to Always Spawn and Ignore Collision or are you spawning it using a different method?

Thanks

3

Hey Sean,

We are nearing our games Early Access release so I do not have the most time right now to debug this. I’m hoping to get around to UE4.14 testing in February but for now we are going to stick with UE4.13.

I was able to avoid this crashing entirely by making sure that we have no static mesh actors simulating physics when the map is loading. We now wait a few seconds after BeginPlay and SetSimulatePhysics(true) on the actors that we want to simulate physics (boats at sea with buoyancy) and this so far has fixed the crash.

What I believe was happening was that when the static mesh actors for our boats were simulating physics they did so very erratically and the physics became very violent when the map was loading. My hunch is that this caused them to be invalid and removed from the world by PhysX and then if our players tried to spawn on the boat actors the server would crash.

By waiting for the map to load and then enabling physics this allows the boat actors to simulate physics from a ‘calm’ start. So far we haven’t had any issues where the map loads without boats or players crash trying to spawn on them. Again, I believe the crash was only from players trying to spawn on boat actors that somehow had their staticmesh or physics state removed by the physx engine but the boat actor still remained as a candidate for spawning by our gamemode…

Hope that makes sense and helps

Best,
George

4

Thanks for providing the additional information. After you get around to your further testing, feel free to leave a comment to reopen this thread and we can continue to investigate the issue.

In the meantime, I’m glad that you were able to find a workaround to avoid the crash.

Have a great day