Maximum multiplayer map size tests

So I was testing the maximum playable space for my multiplayer project compared to arma 3 (this doesnt apply to singleplayer games since you can use origin rebasing & world comp for that)

It appears we have much less space than Arma 3, is their engine using something special for precision / origin rebasing maybe?

The land mass is Altis from arma3 and the orange box is the max kill bounds of UE4 for multiplayer before precision issues happen

According to 4.6 release notes:
The maximum size of an individual world has been increased to approximately 20 kilometers across. This is defined by the ‘WORLD_MAX’ constant in C++ code. It was increased by a factor of four (from approximately 5 km.) ALTIS Clocking-in at 270 km2, Altis truly is the star of Arma 3.

UE4 kill bounds: I got the bounds by going as far from the origin as I could before the player was automatically killed.

Exact bounds in editor CM is:
X -1048527,1048527 | Y -1048527,1048527

Is there any way to get Multiplayer Origin Rebasing feature or is spatial OS the only way??

Should I make heavy use of fog and just limit the flying height ? I really wished I could have got arma sized maps working in ue4 multiplayer :frowning:

I think, and I am just guessing here, that the problem lies in the fact that the engine for ArmA is specificly for ArmA and the UE engine is all-round.

I dont think the engine used with ArmA can be used for iphone, android and ‘simple’ 2D games. UE4 strength is it can be used for all kind of games. And as with everything in life: when you want it all, you have to make compromises :slight_smile:

However, you could open up the UE4 source code and add some code for really large terrain support :wink:

Well, its probably that the networking in arma is more of an mmo type with a different origin/coordinate system, it would be interesting to know how exactly they are able to get greater view distances. Making a big terrain itself isnt the issue, its just when you try to view it from the sky at different angles all at once, for a land mass this size there is all types of terrible view distance artifacts and bugs. So there has to be like culling / rendering improvements to really support bigger environments like arma can. I dont mind seperating the map into different zones / servers though…

Why no “The Crew” map, that looks better, are 5.000Km2 :cool:
I’ll like to see this of multiplayer and network better and like this thread with examples and tests.

*What is the size in km of the orange box 6x6 ??


That isn’t more or less 20km ?

Your landscape scale is wrong.

UE4 limits are near enough 20km. Altis is a little over 16km across.

Arma 3, as with Arma 2, uses very low resolution terrain. Something like 4 meters per polygon. AFAIR

You can easily fit Altis into UE4’s default level bounds.

So what would we need to do to support a map that is around 225km x 225km and get around UE4s limits?

I’ve yet to see a good solution to this. We wanted a seemingly huge world area and ended up just being very creative about how the land/oceans were arranged on the game map to keep actual map size down. We kept flying at a low height, restricted vehicle speed (where vehicles were allowed at all), and made the oceans seem a lot bigger than they were with tricks like fog, fatigue points, cliffs, etc. We also extensively built underground to stack up additional playable space. So in many areas we had a few layers of game space, each one only accessible by seperate portals from other parts of the map (so to the player, it seems like 2-3 seperate map areas). It just requires an insane amount of pre-planning before you start actually building anything. You also have to ensure the areas with higher player density or tons of items aren’t stacked up, as we found this caused a lot of issues. It’s been a massive experiment so far, so I’m interested to know if anyone has found a better solution?

Without something like Spatial OS or the long lost feature of Replicated Origin Rebasing (I thought this was going to get added to ue4?) then the online playable space is about the size of Fortnites battle royale island. Im not sure if PUBG uses their own workaround for floating point precision / rebasing to get the bigger size, but ue4 mp bounds is about 4x more space than ue3/udk was, still not enough imo

Floating point precision pretty much goes wrong when you start hitting maps of around 1.5-2km, at which point you need to be using origin rebasing (which is easier said than done).

We’ve had to use it in HLL, otherwise we start seeing a lot of precision-related issues. In Satellite Command the levels could reach 50km+, but didn’t use origin rebasing because all movement code was done in double precision and was abstracted entirely from UE4.

EDIT: Someone asked me about this in PM:

Note: The vast majority of these precision issues comes from doing so many operations on the numbers themselves.