Build guides

How a build works

You don't package the game yourself. You send the project to Strata as it sits on disk, and Strata does the rest on its own machines:

1. Builds the project with the SimplyStream engine for its engine line, 5.8 or 6.0, and cooks it for the web.
2. Puts the build online.
3. Plays it in Chrome on a cloud GPU in both graphics modes: desktop-class (SM5) and mobile-class (ES3.1). A build that doesn't start, or that shows a visibly broken frame, fails.

A player's browser picks the graphics mode from their GPU, which is why every build is checked in both. Start with Strata covers the three ways to send a project.

Engine lines

Each project builds on one line, chosen when the project is created, and every build uses the newest release of that line.

Strata builds only these two lines. A project made in an older version of Unreal is built with the line you pick, so upgrade it in that line's editor first and fix anything the upgrade breaks.

What to send

Send the whole project folder: the .uproject, Config, Content, Source and Plugins. Blueprint-only projects and C++ projects both build.

strata init writes a .strataignore that leaves out folders Unreal regenerates: Binaries, Intermediate, Saved and DerivedDataCache. You can edit it. Strata keeps its own history of your files and ignores .git, so pushing never touches your Git repository.

Sending a change

Save in the editor, then run strata push from the project folder. Every push is built, put online and checked on a GPU, and the result shows on the project's Builds and Quality pages.

You don't need the editor for this. A coding agent can change the project's files and push them the same way.

Memory

By default, builds run as 32-bit WebAssembly with a heap of 3,998 MB. Keep the game's peak memory below that, including everything it loads while playing.

Multiplayer

Unreal dedicated servers run on SimplyStream too. Strata builds the server to WebAssembly alongside the client, and strata ship builds both, checks them and updates the live server. Browser clients connect over WebSocket, WebRTC or WebTransport. To turn on the server build for a project, ask us.

Each player connection is limited to 10 KB/s by default. If your game replicates more than that, raise the limit in your project's own Config/SimplyStream/SimplyStreamEngine.ini. A value in DefaultEngine.ini has no effect, because the platform's file loads after it. Set both rates on both web net drivers:

[/Script/WebSocketNetworkingSimplyStream.WebSocketNetDriver]
MaxClientRate=30000
MaxInternetClientRate=30000

[/Script/WebTransportNetworkingSimplyStream.WebTransportNetDriver]
MaxClientRate=30000
MaxInternetClientRate=30000

SimplyStream is Unreal first, with early Unity support.

Strata builds Unreal projects only, so a Unity game doesn't go through the steps in Start with Strata. To bring a Unity game to the browser, write to [email protected] or ask on Discord. Tell us your Unity version and what the game needs, such as multiplayer or phone support, and we'll tell you what works for it today.

How big a build is

Each build's page on Builds shows its download size, and how it compares with the builds before it, so you can see when a change made the game bigger.

A build was too big to upload

Besides the web build players get, Strata makes a desktop copy of your game to compare pictures against. Strata uploads that copy in one piece, and one piece can be at most 5.1 GB once packed. A bigger copy fails with a message that gives both sizes. Players never download this copy, but its size comes from the same content as theirs.

Making the game smaller

Most of a game's size is its content, so look there first:

• Lower the largest textures' maximum size, or let Unreal compress them more.
• Remove maps, assets and plugins the game no longer uses, so they are not cooked.
• Keep audio at the quality players hear, not the quality it was recorded at.

Push the change, and the new build's page shows the new size.