Gadgetory

hey everyone this is Steve from gamers Nexus tonight we are at the epic Game Studios in Cary North Carolina and I'm joined by Alan Willard senior technical artist at Epic Games and Alan can you give us a sort of quick overview of the types of things you work on here at epic well I'm a technical artist so I work on all sorts of stuff it depends on the needs of the project for the Gears games I did some levels I did cars that you could blow up I did particle systems I did some sound stuff for Unreal Tournament as well as levels so a technical artist is kind of the jack-of-all-trades we end up kind of getting pulled onto various things as fires break out or as new projects start up to help kind of define how things are gonna work can you give us a top level overview what is tessellation where do gamers actually see it in use sure so if you think of your average surface whether it's a floor or a wall we build them out of what we call quads which are really two triangles that are butted up together to make a square tessellation is a way of doubling that on the graphics hardware so what was two triangles becomes four becomes eight sixteen and so on and when we do that that allows us to do things like displacement or smoothing and increase the apparent detail not only making the surface look higher resolution but also adding bumps and hills and valleys that weren't there before so you get a much higher fidelity surface what what was the origin of tessellation as it pertains to epic games when did it first get implemented so near the end of our active development on Unreal Engine 3 we did the Samaritan demo and we added tessellation working with NVIDIA and you can see it in the Samaritan demo when the character becomes very kind of armored and rocky we increase the amount of tessellation on the character and then added a displacement map and that displacement is what takes his default shape and enhances it to get that kind of angular rocky look so going forward if if I'm a gamer I'm playing some kind of modern game and I enable or disable tessellation in the settings where should I be looking to see the most immediate visual impact so mostly it'll be in the silhouettes of things right if you have a boulder and it looks fairly low poly without tessellation when you turn on tessellation you'll start to see more curvature it will get smoother small things like bumps and gouges will start to become more apparent not just looking straight at it but also in the outline around the object is this dependent upon the camera angle it can be it depends on the implementation we tend to bias the displacement and tessellation based on camera distance right if you have a small object in its way far away you really don't want to spend any performance doing anything extra to it until it comes close enough to the camera that it's it now important to the the players eye right there's no point in wasting time on it and an earlier example we were talking about just pre-interview when looking at a flat surface like a wall with a brick texture on it so my understanding is that tessellation can help give this an appearance of depth right so if you think of a wall as just being a flat surface you can do a lot of shader tricks to make it look better what we call bump offset where we shift the location of pixels based on the camera angle and that can give you the sense that the bricks have depth and and and are coming out of the surface a bit but what you'll never get is you'll never get a silhouette off of that kind of technique so displacement and tessellation allow us to increase the triangle density and then actually push and pull those triangles in out to the sides whatever to get those shapes to really come off of that surface and then lighting and shadowing can can really work with those shapes too to sell the final look call on a performance side what's sort of the the performance impact here is it is it large or it depends on the GPU displacement and tessellation are typically done completely on the GPU so if the the project or the game that you're looking at is GPU bound where they're doing all the work that can be done on the GPU while staying within their performance boundaries then turning tests off we'll get you some performance improvements games do typically tend to be GPU bound we all want our games to look as good as possible so we turn on all the bells and whistles so unless you're you're running on an extremely high-end machine you'll notice some difference in performance but as you do get into the higher-end spec it'll just enhance the look without any significant performance cost very cool so for more information on tessellation check the link in the description below for the full article and any any projects we're talking about here today just to direct people towards new things obviously there's the Unreal Engine which we've released for free to everyone you can download it at Unreal Engine comm create your own projects we've got massive amount of tutorial content demonstrations we have a learn tab in our launcher that lets you get right in and see how we're building stuff we have weekly trip twitch streams covering everything from our community for tonight information Unreal Tournament information which is available through the launcher tab as a pre-alpha you can download it play the game right now and if you're so inclined you can even get in and start working on it you can actually build content and make it part of the game right from your home very cool so again links in the description below for more information and we will see you all next time you