Current focus

• Better API reference documentation

• Channels (ordered/unordered, reliable/unreliable)

• Synchronizing Lists

• Improvements to Uniqueness

• Performance improvements

• Scene transitioning improvements

High priority

• Fully authoritative Simulator

• Improvement to online dashboard logs

• More code samples

  • Inventory

Priority

• Debug tools

• Built-in network condition simulation

• Network profiler

• Global KV store

Backlog

• Support for multiple Simulators and Replicators in a single project

• More logging and diagnostics tools

• Additional server regions

• Support for lean pure C# clients and simulators without Unity

• Fast network engine with cloud scaling, state replication, persistence and auto load balancing.

• Easy to develop, iterate and operate connected games and experiences.

• SDK allows developers to make multiplayer games using Windows, Linux or Mac, targeting desktop, console, mobile, VR or the web.

• Game engine plugins and visual tools will help even non-coders create and quickly iterate on a connected game idea.

• Scalable from small games to large virtual worlds running on hundreds of servers.

• Game-service features like and .

Network engine

At the core of coherence lies a fast network engine based on bitstreams and a data-oriented architecture, with numerous optimization techniques like delta compression, quantization and ("Level of Detail") to minimize bandwidth and maximize performance.

Authority models

The network engine supports multiple models:

• Client authority

• Server authority

• Server authority with client prediction

• Authority handover (request, steal)

Different authority models can be mixed in the same game.

Persistence

coherence supports out of the box. This means that the state of the world is preserved no matter if clients or simulators are connected to it or not. This way, you can create shared worlds where visitors have a lasting impact.

Engine support

General features

• Custom UDP transport layer using bit streams with reliability

• WebRTC support for WebGL builds

• Smooth state replication

• Server-side, Client-side, distributed authority

Unity SDK

• Unity SDK with an intuitive no-code layer

• Per-field adjustable interpolation and extrapolation

• Input queues

• Easy deployment into the cloud

Optimization and performance

• Per-field compression and quantization

• Per-field sampling frequency adjustable at runtime

• Unlimited per-field levels of detail

• Areas of interest

Hosting and services

• Online Dashboard for management and usage statistics

• Automatic server deployment and scaling

• Multiple regions in the US, Europe and Asia

• Player accounts with a persistent key/value store

coherence is a network engine, platform, and a series of tools to help anyone create a multiplayer game.

Our network engine is our foundational tech. It works by sharing game world data via the Replication Server and passing it to the connected Clients. The Clients, in this context, can be regular game Clients (where a human player is playing the game) or a special version of the game running in the cloud, which we call "Simulator".

While coherence's network engine is meant to be game engine agnostic, we offer SDKs to integrate with popular engines (for instance, Unity).

The coherence Unity SDK provides a suite of tools and pre-made Unity components, and a designer-friendly interface to easily configure network entities. It also takes care of generating netcode via a process called "Baking". In fact, simple networking can be setup completely without code.

But coherence is not just an SDK.

The is a platform that can handle scaling, matchmaking, persistence and load balancing, all automatically. And all using a handy . The coherence Cloud can be used to launch and maintain live games, as well as a way to quickly test a game in development together with remote colleagues.

For more information about how a network topology is structured in coherence, check out this video:

Important concepts

A lean and performant smart relay that keeps the state of the world, and replicates it efficiently between various Simulators and game Clients.

The Replication Server usually runs in the , but developers can start it locally from the command line or the Unity Editor. It can also be run on-premise, hosted on your servers; or be hosted by one of the Clients, to create a scenario (Client-hosting).

A special version of the Game Client without graphics (a "headless client"), optimized and configured to perform server-side simulation of the game world. When we say something is simulated "server-side", we mean it is simulated on one or several Simulators.

Game Clients

A regular build of the game. To connect to coherence, it uses our.

Clients (and Simulators) can define (Live Queries), levels of detail, varying simulation and replication frequencies and other to control how much bandwidth and CPU is used in different scenarios.

This is the process of specific to the game engine that takes care of network synchronization and other network-specific code. This is also known as "baking", and it's a completely automated process in coherence, triggered by just pressing a button. You can however for very advanced use cases.

An easy-to-manage platform for hosting and scaling the backend for your multiplayer game. The coherence Cloud can host a Replication Server, but also Simulators.

In addition, every project can have a showcase page where you can host !

Our cloud-backed dashboard, where you can control all of the aspects of a project, configure matchmaking, Rooms, Worlds, and keep an eye on how much traffic the project is generating.