With constant updates to the UDK, Epic provides the latest features of the Unreal Engine for free if you're just looking at game development as a hobby. If you're aiming to start up your own development studio, the licensing terms for the UDK fit even in the smallest of budgets. If you're looking for AAA quality, the UDK is where you'll find it.
The next folder, Development, is where most of our work will take place. You may have heard people talk about a game's source code before. The Development\Src folder is where our game's source code will go. If we look in the Src folder we see that it isn't empty, there are a lot of folders already in there. Epic provides the source UnrealScript files for reference, to make it easier to learn how to make our own code. As Indiana Jones might say if he were a programmer, "Seventy percent of programming is reading the source code." One important thing to remember: NEVER ALTER EPIC'S SOURCE CODE! A lot of the files have C++ code behind the scenes, and altering these files could break them since we don't have access to the C++ code. All the work we do will be creating our own files to work with.
ConTEXT is a freeware text editor designed to make working with various programming languages easier. It has text highlighting to make reading code quicker, and tools to make compiling code as easy as pressing a button. Let's install it so we can use it in our project.
nFringe is an IDE (Integrated Development Environment) that allows programmers to work with UnrealScript in Microsoft Visual Studio 2005 or 2008. It includes a debugger that allows us to stop the game while it is running to see what is happening in script. There is a free version available for non-commercial work, but if you'd like to use it for commercial projects there is a licensing fee. If you have Visual Studio and would like to try it out, head over to and get the latest version!
Rachel Cordone is a game designer and programmer who has been working with the Unreal Engine since the 1990's. She has worked with various game and simulation companies since 2003 on everything from PC, console, mobile, to VR and AR projects. For the past decade, Rachel has offered remote contract programming services to training software development companies including Northrop Grumman and Parsons Brinkerhoff. On the side, she makes video games through her company, Stubborn Horse Studios. She also wrote the book Unreal Development Kit Game Programming with UnrealScript for Packt.
UDK is a free version of the commercially available Unreal Engine which allows professional and indie developers alike to work with industry tools to create stunning 3D games. In this article, we'll show you what UDK is capable of and share books, tutorials, and suggestions for getting started making levels and games with it.
UDK can also be used to practice other disciplines besides game development. UDK actually originated as the mod tool which is released with every game that Epic Games ships and was designed to work as a level editor for those games. If want to dive head first into the code and start adding new content or game mechanics you can, but UDK is also a great playground to try your hand at level design as well.
Finally, let's look at licensing with UDK. UDK is free to use for development and as long as the product you make is not making you a profit you don't have to pay anything. Once you start making a profit you can make up to $50,000 across every product you publish with UDK before you owe Epic any royalties. (After that you have to start giving Epic a 25% cut of your profits.) There are other details to consider, so if you want more info on licensing, head to this page.
First, while it is possible to make almost any 3D game you can imagine in UDK, making things that are not first person shooters can be quite challenging. There are a lot of ways you can modify the system, but without extensive knowledge and understanding of programming concepts you won't get as far, so if that's what you want to do you must be prepared to look into programming tutorials as well.
The first-generation Unreal Engine was developed by Tim Sweeney, the founder of Epic Games. Having created editing tools for his shareware games ZZT (1991) and Jill of the Jungle (1992), Sweeney began writing the engine in 1995 for the production of a game that would later become a first-person shooter known as Unreal. After years in development, it debuted with the game's release in 1998, although MicroProse and Legend Entertainment had access to the technology much earlier, licensing it in 1996. According to an interview, Sweeney wrote 90 percent of the code in the engine, including the graphics, tools, and networking.
According to Sweeney, the hardest part of the engine to program was the renderer, as he had to rewrite its core algorithm several times during development, though he found less "glamorous" the infrastructure connecting all the subsystems. Despite requiring a significant personal effort, he said the engine was his favorite project at Epic, adding: "Writing the first Unreal Engine was a 3.5-year, breadth-first tour of hundreds of unique topics in software and was incredibly enlightening." Among its features were collision detection, colored lighting, and a limited form of texture filtering. It also integrated a level editor, UnrealEd, that had support for real-time constructive solid geometry operations as early as 1996, allowing mappers to change the level layout on the fly. Even though Unreal was designed to compete with id Software (developer of Doom and Quake), co-founder John Carmack complimented the game for the use of 16-bit color and remarked its implementation of visual effects such as volumetric fog. "I doubt any important game will be designed with 8-bit color in mind from now on. Unreal has done an important thing in pushing toward direct color, and this gives the artists a lot more freedom," he said in an article written by Geoff Keighley for GameSpot. "Light blooms [the spheres of light], fog volumes, and composite skies were steps I was planning on taking, but Epic got there first with Unreal," he said, adding: "The Unreal engine has raised the bar on what action gamers expect from future products. The visual effects first seen in the game will become expected from future games."
Unreal was noted for its graphical innovations, but Sweeney recognized in a 1999 interview with Eurogamer that many aspects of the game were unpolished, citing complaints from gamers about its high system requirements and online gameplay issues. Epic addressed these points during the development of Unreal Tournament by incorporating several enhancements in the engine intended to optimize performance on low-end machines and improve the networking code, while also refining the artificial intelligence for bots to display coordination in team-based gamemodes such as Capture the Flag. Originally planned as an expansion pack for Unreal, the game also came with increased image quality with the support for the S3TC compression algorithm, allowing for 24-bit high resolution textures without compromising performance. In addition to being available on Windows, Linux, Mac and Unix, the engine was ported through Unreal Tournament to the PlayStation 2 and, with the help of Secret Level, to the Dreamcast.
By late 1999, The New York Times indicated that there had been sixteen external projects using Epic's technology, including Deus Ex, The Wheel of Time, and Duke Nukem Forever, the latter of which was originally based on the Quake II engine. Unlike id Software, whose engine business only offered the source code, Epic provided support for licensees and would get together with their leads to discuss improvements to its game development system, internally dubbed the Unreal Tech Advisory Group. While it cost around $3 million to produce and licenses for up to $350,000, Epic gave players the ability to modify its games with the incorporation of UnrealEd and a scripting language called UnrealScript, sparking a community of enthusiasts around a game engine built to be extensible over multiple generations of games.
In October 1998, IGN reported, based on an interview with affiliate Voodoo Extreme, that Sweeney was doing research for his next-generation engine. With development starting a year later, the second version made its debut in 2002 with America's Army, a free multiplayer shooter developed by the U.S. Army as a recruitment device. Soon after, Epic would release Unreal Championship on the Xbox, one of the first games to utilize Microsoft's Xbox Live.
While Unreal Engine 3 was quite open for modders to work with, the ability to publish and sell games meant using UE3 was restricted to licenses of the engine. However, in November 2009, Epic released a free version of UE3's SDK, called the Unreal Development Kit (UDK), that is available to the general public.
In February 2012, Rein stated "people are going to be shocked later this year when they see Unreal Engine 4"; Epic unveiled UE4 to limited attendees at the 2012 Game Developers Conference, and a video of the engine being demonstrated by technical artist Alan Willard was released to the public on June 7, 2012, via GameTrailers TV. One of the major features planned for UE4 was real-time global illumination using voxel cone tracing, eliminating pre-computed lighting. However, this feature, called Sparse Voxel Octree Global Illumination (SVOGI) and showcased with the Elemental demo, was replaced with a similar but less computationally expensive algorithm due to performance concerns. UE4 also includes the new "Blueprints" visual scripting system (a successor to UE3's "Kismet"), which allows for rapid development of game logic without using code, resulting in less of a divide between technical artists, designers, and programmers. 2b1af7f3a8