S&box

is a platform and game development toolkit developed by Facepunch studio powered by a highly modified version of , planned to be a spiritual successor to . Initially, the development was based on , but as soon as came out, Facepunch immediately requested the engine branch of the newly-published game. A few weeks later gave Facepunch access to the terabyte large repository, after which, in 2020, S&box's transition to was announced. This is the first (and currently only) time that Source 2 has been licensed to third-party developers.
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== User Access ==
S&box is currently in open developer preview.
Access is available from the S&box site here. Users must sign in through Steam on website to claim access to the preview.
== Features ==
 runs on highly modified version of with the following features:
; Box3D physics
: A modified version of Rubikon physics engine without Valve specific code that can be quickly updated. Originally referred to as Izabu
; Hotloading
: The ability to see code changes take effect immediately with blazing fast hotloading, no need to compile and restart your game.
; Visual Scripting
: With ActionGraph you can create interactive experiences in your levels, without having to write a single line of code, or having sprawling chains of entities. Not meant to program a game entirely in it, but to augment it.
== UGC Content Distribution ==
Instead of using the Steam Workshop for storing UGC Content uses a custom web based backend called s&box Game.
== Scene System ==
 does away with the legacy Entity System and utilizes a Scene System which lets you have a Scene that is a collection of Game Objects to make up the game world. closely resembling the way things are done in Unity
== Maps ==
Mappers are provided with a modified version of the Source 2 Hammer map editor, with some parts exposed for C# scripting for increased flexibility. This includes integration with the scene system which lets you place game objects with components within the map just like you would in the scene editor.
Project control panel
In the projects menu in the dev tools, you can restrict map selection for your game mode. You can limit it to specific curated maps or maps tagged with supporting the game mode. 
Publication
Currently, maps can be included with a game mode or released as a separate project(one for each map). The map is published by clicking on a special button in the projects menu in the developer toolkit.
Characteristics
== Programming ==
S&box user content is programmed with C#, Microsoft's managed, object-oriented programming language of .NET fame. S&box includes an API which provides bindings to the underlying Source 2 engine and to Facepunch's middleware. All code in user content is distributed in source form, which S&box later compiles on-demand with Roslyn. Language support is stated to permit C# 11, indicating that S&box requires a .NET 9.0.0 runtime in order to function, which is bundled with the sbox installation. Only a specific subset of the baseline .NET Core complement is available for use.
Security is a primary concern with user content. C# and its ubiquitous pairing with .NET is a software ecosystem many magnitudes larger, more complex, and more powerful than s&box or Source 2. Awarding unchecked access to this leviathan would effectively turn user content into fully-fledged applications with potentially unlimited access to the host computer. To this end, s&box restricts the use of certain types and namespaces. For example, access to the local file system is only available through a sanctioned abstraction layer; System.IO.File and similar types may not be used. This practice is common among applications which attempt to distill down .NET into a limited "scripting" platform for untrusted user code.
Currently, the C# API and tools are in a preview stage of development. Breaking changes happen often and the API is not yet complete.
There are many similarities between the use of C# in S&box and the use of the more primitive Lua language in . Many concepts of Gmod's Lua environment have been carried over, including limited access to the language's features and "hot reloading" of edited code.
S&box will also have a visual scripting solution called ActionGraph, which enables a developer to script events via nodes.
== Shaders ==
You can create your own shaders either through HLSL or through the provided Shadergraph Editor and customize their interface for the material editor. 
S&box supports HLSL 2021 & Shader Model 3.0 up to 5.0. 
 
== External links ==
For Developers
* Report a bug
* Asset.Party
* Documentation
* Wiki
Other
* News
* Forum
* Discord
Category:S&box