Hello, I am an unreal engine 4 user trying to make a racing game with friends. We heavily rely on the static mesh’s CPU access feature in order to make our antigravity racing physics work. It works consistently on Intel CPUs and we never had a problem before that.
Recently, a guy in our team changed for an AMD CPU and when he was testing the game, the character would get teleported so far, at random, that we could notice the rounding errors of floats. It happens consistently on his pc, may it be in the PIE, on standalone, or on a build he compiled, even though while he was not testing out the game, everything was fine in the editor.
Even more interesting, his builds showed the exact same problems on our intel machines when he transfered it to us, whereas our build compiled on intel would work as intented on his AMD machine. This led us to believe that there was a problem with the compiler when compiling on AMD.
Also, the fact that every other UE4 project would work on his machine as they never used the CPU access feature also led us to believe that this feature might be involved in the issue.
So I’m reaching out to Devs as people never seem to have our problem, maybe because this feature isn’t used a lot, and maybe because most UE4 devs are on intel. I wanna know if this issue was reported once, and if our hypothesis is right about the cause of the issue. Oh and fixing it would be awesome!
For the record, here is a build i compiled on intel, playing on an intel machine:
And here is thebuild my friend compiled on AMD, playing on the same intel machine as the one used for the other video:
Thanks for reading this, this problem is litteraly blocking our friend as he cannot test what he makes in unreal, I would apreciate a quick response just to acknowledge the problem, thank you again.