Physics FPS lag and shifting people in unintended directions

Bug Reports Engine Bugs
#1

There seems to be an issue with the Large Un-anchored Objects in the Terrain Water (Possibly happening without water as well) with a number of people standing on that object.
This issue causes the player to fling all over the place and causes Major FPS lag in one of my games, which I never had any real issue with it before.

The game rely’s on the Roblox Physics to Sink the ship, slowing weighing the ship down until it goes under.

This issue started happening only a few days ago I believe when I started getting complaints from players having serious performance issues and getting flung all over the place. Before, my game was running fine, not much lag and there was no issue with people being flung all over the place.

This is not isolated to only my game, Similar games using similar methods of Sinking are having the same issue.
My game where the Issue started happening

A similar game which this issue seems to also be occurring as well.
https://www.roblox.com/games/134761473/Sinking-Ships-V-9-9

Below shoes the FPS drop, the video has only 15-30 FPS(which is definitely not the issue with the hardware of the computer) Although the fps drop is hard to notice in the video.

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#2

Could you have a look at the microprofiler, and post it here?

1 Like
#3

image
image2560×1345 1.43 MB

Of course there was lag when the ship is sinking but it never was this bad.

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#4

Ok I’m not sure what’s thew source of your issue. Connecting with other staff.

Just a note: you are still using the legacy solver. We are not actively supporting it anymore. Moreover, early next year it will be completely removed. Please migrate to the new solver.

#5

kni0002 - as chefdeletat points out, we are deprecating the legacy solver this coming March. Please switch to the PGS solver and let us know if this issue is still reproducible.

Thanks.

#6

Thanks, I switched over to the PGS solver and noticed that the movement problem is more noticeable with people being moved far off their original position, which probably was the source of the lag.

EDIT: I managed to partially fix this issue on my game, making it playable but not an Ideal fix for me.

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image554×668 20.5 KB

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#7

Please don’t just post saying that you have fixed the issue. Explain the issue and the fix so that you can help anyone that runs into a similar issue.

5 Likes
#8

80-90% Fixed
I fixed the issue by using body velocity/body gyros, although I’m still getting lag spikes but the players dont move all over the place anymore, doing it this way and its not ideal.
Still would be good to see this issue get resolved anyways, as I preferred the old method.

Sorry I didn’t post any extra information.

1 Like
#9

So is the issue you are describing the fact that the characters shift a little bit while standing on sinking ships? Is that a correct description?

#10

Yes, I believe so or parts that are sitting in the terrain water Un-Anchored and are moving. I think this issue happens on servers with players where a large model? is sitting in the terrain water with quite a few parts is moved around with players standing on it. But the players much further then what the videos show… I managed to get shifted far from the original spot I was standing.

1 Like