Do I Need To Download Unreal Engine For Fortnite

What is Fortnite: Battle Royale?

We recently released a new PvP mode in Fortnite: Boxing Royale. This new game mode drops 100 players into a large five.five km^2 playable area to duke it out and come across who will exist the last player standing. The scale of these requirements presented the Fortnite development team with several challenges, which will be discussed hither.

In the grade of developing the Battle Royale game mode we've made many performance, retentivity, and workflow optimizations that not simply benefit Fortnite: Battle Royale only every developer using Unreal Engine iv, peculiarly those building games with similar requirements.

All of these improvements are already available in both Perforce and GitHub. Many will send in Unreal Engine 4.18 this month with the rest shipping in 4.19.

Defended Server Performance

Our first challenge was to optimize the dedicated server and then that information technology could handle 100 simultaneous players, maintain 20hz, and minimize bandwidth.

With every frame the server sends updates to all actors near that player. That ways for each player nosotros demand to determine all relevant actors, figure out what has changed on those actors, and ship a bundle to that player with the differences. In order to minimize CPU time and bandwidth we need send the minimum updates needed to provide a good experience for players.

Much of this work was profiling and optimizing the game code just we as well found many engine optimization opportunities along the manner.

Here are some of the defended server optimizations we made for the engine:

Batched level streaming RPCs to reduce the number of RPCs that need to be sent to clients when they connect. (Will be in 4.19)
Brand the Bone socket buffer sizes configurable and enhance them for Battle Royale. This prevents simultaneously connecting clients from flood these buffers resulting in excessive server load. (Will be in iv.19)
Reduce bandwidth for CharacterMovement RPCs when the character is not standing on any component, such as when jumping or falling. (Will be in 4.19)
Added the power to limit how many players receive updates from the server per frame. Nosotros set the limit to 25 in the entrance hall and 50 during gameplay. (Volition be in iv.nineteen)
Limit the charge per unit at which clients send motility updates to the server. Prevents clients running at high framerates from causing excessive load on the server. (Shipped with 4.17)
Added an option to not replicate client ping times to other clients as it results in a lot of network traffic when at that place are many players. (Will be in 4.nineteen)
Removed several retentiveness allocations during replication in FArchive::SerializeIntPacked and changing how CompatibleChecksum is calculated. (Volition be in 4.19)
Switched property type comparisons from strings to FNames for speed during replication. (Will be in 4.19)
Added a style to view a dedicated server'south network stats on a client in real time to more than easily run across stats for deject-hosted servers. (Will be in 4.19)
Changes to the ability organisation to better account for relevancy, which greatly reduces replication cost when using the power organisation. (Will be in 4.19)

Building and Rendering a Large Map

The map in Fortnite: Battle Royale has a playable area of v.5km^2. Yous can come across the entire map at once when parachuting in and we wanted to back up long view distances during gameplay. Nosotros knew that nosotros needed to optimize our level-of-detail solution to make that possible.

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We used the Hierarchical LOD (HLOD) characteristic in the engine, backed by Simplygon, to combine regions of the map into single depression-poly meshes that could be drawn in a single draw call when viewed from a altitude. Those tools already be – we employ them in Paragon – but we needed to brand changes to allow our artists to exist more efficient.

The way the map was broken up and then that artists could interact on it didn't mesh well with our HLOD tools. We made some changes to HLOD to meliorate support that workflow and added a commandlet to rebuild all HLODs in the map that could run overnight rather than requiring artists to rebuild HLODs locally. (Will be in 4.nineteen)

Shipping on Console

The extended view distance and player counts of Boxing Royale presented several performance and retentiveness challenges on panel requiring u.s. to brand improvements, especially relating to memory. Much of this work was game-side content optimization but nosotros too made a number of improvements to the engine.

Here are some of the console improvements, which volition ship in iv.18:

[XboxOne + PS4] Improved our low-level memory tracking tools to better identify potential memory optimizations.
[XboxOne + PS4] More than efficient volume texture updates, which reduced height retention by 240MB+.
[XboxOne] Added options for different render target layouts to maximize bandwidth utilization on the GPU depending on what rendering features are enabled.
[XboxOne] Reduced memory overhead in D3D12 descriptor heaps, and saved 120MB.
[XboxOne] Allocated and freed return targets on-the-fly to reduce retention usage by 100MB+.
[PS4] Optimized how we handle the texture streaming and defragmentation pools, saving 300-400MB.

While working on Battle Royale we identified some problems with input latency in the engine that particularly afflicted 30Hz games. We were able to make improvements to thread synchronization, reducing latency by around 66ms (the reduction will be effectually half that in a 60Hz championship) to address this trouble. These changes make a noticeable improvement to the experience of the game, making it more responsive and easier to aim. (Will exist in iv.19)

More to Come up!

These are just the engine improvements that came out of shipping the commencement version of Fortnite: Boxing Royale. Having had this experience, nosotros've identified further improvements nosotros'd similar to make, especially related to level streaming and editor operation when working with very large maps, that will make our game teams and our users across the industry more than efficient.