Unreal Engine 4 Preview: Light on Smoke


It seems like yesterday that I was sitting in GDC 2011, watching Epic Games reveal new upgrades to Unreal Engine 3. Just over a year later, and we’ve moved on to the next iteration of the engine, Unreal Engine 4, which will have far-ranging consequences for games of all styles and on all platforms.

Epic’s presentation at E3 2012 began with a video demonstrating the engine’s capabilities, which depicts a horned, fiery demon-king awakening from an icy tomb and striding outside, as a volcano explodes behind him. The hyperbolic visual splendor — as you might guess — is better seen than described, so first, watch the video. As you watch, keep an out for the profusion of a. particles and b. lighting effects, two crucial elements of Unreal Engine 4.

Spectacular, wasn’t it? Epic is hoping you noticed the snowflakes and sparks, which benefit from Unreal Engine 4′s new particle system. First and foremost, this means more particles — millions of them on the screen at any one time. In addition to simply being more numerous, the particles behave more realistically. They will be fully dynamic, using the power of the GPU (the E3 demo ran on a single GTX 680 card) to react in real-time to forces in the environment. They’ll also be fully lit — Unreal Engine 4 can render the effect of light on smoke or even keep track of floating particles that aren’t even visible until light is shined on them.


Lighting was the other primary focus of the presentation, and Epic has made big strides in this department. Like particles, lighting in Unreal Engine 4 will be fully dynamic and real-time — developers will no longer have to rely on pre-ordained outcomes and effects if they’d prefer not to. The most impressive reveal was the indirect lighting system — objects now reflect, absorb, and transmit light in a realistic manner. A single light source — the sun, say — can now be used to light an entire room through a small hole in the ceiling. Light will bounce off surfaces to fill all but the most hidden corners.

The system will also take advantage of jargon-rich effects like “immiscive surfaces” (as a surface changes, the way it reflects light changes), “sub-surface scattering,” and “differed decals.” Iterative lighting will enable the engine to react to changes in the environment, like the sun moving across the sky.


As the previous paragraph might make clear, my skills lie more in being a critic and a writer than they do in parsing the complex, technical process of making video games. Thankfully, Epic saved their best for last, showing off an element of Unreal Engine 4 that is really exciting, even to a relative layman: its ease of use.

Slate, the engine’s rewritten user interface, is packed with features that will make creating games easier for everyone. Code compiles in seconds, and designers can jump seamlessly from the code to the editor to playing the game from a player’s perspective with a few clicks of the mouse.

Unreal 3 featured a technology called “Kismet Scripting,” which has been replaced by “Kismet Blueprints,” a visually striking, flow-chart-style view of scripting and coding that threatens to break the monopoly once held by programmers on the most granular aspects of game design.


Using Unreal Engine 4, the game creators of tomorrow will be able to make changes to a game while it’s running, to the script, the tools, the content, and the code — all in real time. Forget volumetric particles — this is the important innovation. Ease-of-use means more games, better games, more creative games, more unique games — I can’t wait to play them.

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1 Comment on Unreal Engine 4 Preview: Light on Smoke


On July 1, 2012 at 11:19 pm

“Using Unreal Engine 4, the game creators of tomorrow will be able to make changes to a game while it’s running, to the script, the tools, the content, and the code — all in real time.”

Never Heard of Unity?