General Discussion - An overview of Deterministic Lockstep, the upcoming change to address Desync - Forum

For those in the community who are interested, here's an excellent introduction to and overview of Deterministic Lockstep (with visual representations), the technique GGG has announced is going to be used to address Desync: http://gafferongames.com/networked-physics/deterministic-lockstep/ All that and a bag of chips!	Posted by Mooginator on Apr 15, 2015, 7:18:24 PM Quote this Post
Interesting read, though a bit too high-level for me. I'm interested in how the devs (is it just Rory?) managed to address issues like floating point rounding. IIRC it was stated a while back that they don't round consistently across all hardware setups, which can cause divergence. Maybe they just went through all the variables and converted them to more reliable setups? If so this really was a lot of work put in to the system. IGN: Ikimashouka, Tsukiyattekudasai, DontCallMeMrFroyo	Posted by gilrad on Apr 15, 2015, 7:51:57 PM Quote this Post
Good read. Was especially impressed at the last section, where everything still stayed in sync despite 25% packet loss. A comprehensive, easy on the eyes loot filter: http://www.pathofexile.com/forum/view-thread/1245785 Need a chill group exiles to hang with? Join us: http://www.pathofexile.com/forum/view-thread/1251403	Posted by Antnee on Apr 15, 2015, 7:59:46 PM Quote this Post
Interesting thanks for sharing. Will using deterministic lockstep require vsync? Or maybe fps locked at a multiple of 60? Because aren't the steps that are locked together frames? When I kill a man he stays dead.	Posted by mucker on Apr 15, 2015, 8:06:31 PM Quote this Post
" gilrad wrote: Interesting read, though a bit too high-level for me. I'm interested in how the devs (is it just Rory?) managed to address issues like floating point rounding. IIRC it was stated a while back that they don't round consistently across all hardware setups, which can cause divergence. Maybe they just went through all the variables and converted them to more reliable setups? If so this really was a lot of work put in to the system. This game does not use floating point math. It's all integer math.	Posted by Qiox on Apr 15, 2015, 8:10:32 PM Quote this Post
" Negitivefrags GGG Lead Programmer 42 points 5 days ago We mostly don't use floats for the gameplay code. Some of the work we still have to do is converting a few places where floats did end up being used over to integer arithmetic. http://www.reddit.com/r/pathofexile/comments/324u94/rewrite_of_netcode_with_a4_to_reduce_dsync/cq7z1dp Casually casual. Last edited by TheAnuhart on Apr 15, 2015, 8:31:08 PM	Posted by TheAnuhart on Apr 15, 2015, 8:30:05 PM Quote this Post
" Qiox wrote: " gilrad wrote: Interesting read, though a bit too high-level for me. I'm interested in how the devs (is it just Rory?) managed to address issues like floating point rounding. IIRC it was stated a while back that they don't round consistently across all hardware setups, which can cause divergence. Maybe they just went through all the variables and converted them to more reliable setups? If so this really was a lot of work put in to the system. This game does not use floating point math. It's all integer math. Statement will be true in two months' time. Or possibly became true within the past year. IGN: Ikimashouka, Tsukiyattekudasai, DontCallMeMrFroyo	Posted by gilrad on Apr 15, 2015, 10:37:25 PM Quote this Post