Technical and Visual Analysis of Overwatch

原文：https://80.lv/articles/overwatch-technical-overview/

http://polycount.com/discussion/170394/technical-study-overwatch-image-heavy/p1

Timothy Bermanseder, co-founder of Cardboard Keep, studied the beta-version ofOverwatch and found some very interesting technical details. He gave his analysis of the special effects, materials, assets and visual design of Overwatch. Check out the details inside (this is an update of the forum post on Polycount with additional comments from the author).

Introduction

G’day, I’m Timothy Bermanseder, from Canberra, Australia. I am co-founder of Cardboard Keep, a small indie studio who just released our first game Warden: Melody of the Undergrowth on PC, Mac and Linux.

When I was young I used to make Doom maps with my dad, from there I went to play with map editors in any game that had them and after school attended the AIE (Academy of Interactive Entertainment) studying 3D art. It was here that I met fellow game devs who wished to start their own company and make their own games.

I lean mostly into technical art, but being part of an indie team means I wear many hats, we are a small team so ultimately I end up doing a lot of the art. Today as millions of players around the world are launching their Overwatch accounts I want to present my simple technical analysis of the game’s visuals.

Almost every gamer has heard of Overwatch and I got the chance to play in the open beta in the beginning of May 2016. I admit I was skeptical of the game, but from all the information I had seen it was quite beautiful aesthetically, so I gave it a whirl and had an absolute blast. As a 3D artist and often responsible for turning an artstyle into reality, I was intrigued by how they managed to get that awesome pixar look, and running silky smooth.This led me to start jotting down notes about things I noticed – eventually I had so many I figured I’d compile them and share them with the community. All of this was simply my own observation. I had no part in the creation of Overwatch.

Material Production

I believe (but don’t know for sure) that Overwatch was a testbed for moving into a PBR (Physically Based Rendering) workflow, using modern rendering technologies to reach for the film or Pixar look. Delving into the texture maps the game uses we can see plenty of maps that could very well be metalness or roughness maps.

Blizzard have a long history with engine tech and blending materials from Starcraft and WoW, and they made use of this knowledge here to milk the most out of their materials in Overwatch. They layer different materials together to create organic and natural surfaces – from puddles and dirt in the cobblestones, to sand catching in bricks and moss growing up rocks.

This use of blending is empowering to an environment artist who likely needs to work with tiling textures and a few static props yet cannot afford to let the scene feel stale.

Character Creation

I was initially most curious about their polycounts as it would give me a starting point for my own poly budget, were I to work on a similar project. Upon study of their character models, I discovered that their characters do not use blendshapes for facial animation, rather they use a bone method.

Almost every character had some kind of dynamic object attached to them, be it hair, little particles or a dangling keychain from their weapon. These little touches add secondary motion into the characters as they move, breathing more life into their animations.

The mesh flow of characters is wisely targeted to have the highest density in the most seen places; their hands, face and weapons are much denser than their legs or backs, for example.

For some characters, they would use rectangular textures 1024×2048 rather than square textures. This is likely whenever characters had long UV islands that they wanted to keep straight rather than deal with painting at an angle and dealing with aliasing.

Environment Production

Blizzard games are well known for their big readable art styles and Overwatch is no exception. The use of big baked-in bevels really stood out to me. It’s so Blizzard and they really make it work, helping give all the objects in the world a softer, rounder finish without needing to model actual bevels onto everything.

Likewise, they made use of corner pieces to both cover seams, break up repetition and give a chunkier more 3D world. The Overwatch team seems to have tried to avoid sharp 90 degree angles, using either a corner piece or an actual bevel to prevent a level feeling like a series of boxes.

Intersections

Looking at the mesh intersections I found in Overwatch was actually a huge relief. From having to build many game levels myself, it is so very easy to overlook a slightly stretched UV or a piece of geometry clipping into another object.

In fact, if one were to enforce no intersecting geometry you would find yourself building far too many unique assets, unable to kitbash pieces together.

What Blizzard have done is make sure all the intersections are smaller, minor objects often of the same material type. That is, stone stairs clip into a stone wall, etc.

This minimizes the players’ ability to notice or care about these things while allowing them to much more quickly build a large level.

Lighting

As mentioned above, the use of large painted bevels in the texture allow the objects in the world to appear softer and smoother, giving a dramatic rim light feeling for completely free. This lends itself to their art style which strives for a bigger than life comic book feel.

They also make good use of cubemap reflections, not just in their windows, giving a great sense of depth but also in the subtle reflections of puddles and even slightly metallic surfaces.

Another clever trick I observed with the lighting was the adding of moresubtle detail only in the specular or shiny parts of a material. This works to keep the material readable and simple at distance, but closer up and with lighting, little details pop up out of the texture. This does a great job to break repetition in the tiling of textures.

VFX

In it’s comic book style, Overwatch makes great use of exaggerated explosions and muzzle flashes, yet balance them well enough to not be over the top and wash out all the action.

Overwatch’s Style

Polished, bright and colourful. These are hallmarks of Blizzard and they execute it really well in Overwatch.

What I love most about Overwatch is that it proves Pixar quality art is possible in both real time and during gameplay. The style reminds me of being a child reading comic books and what could be rather than the harsh reality of a video game full of polygons.though I admit through doing this analysis I can’t unsee the seams and intersections I discovered, Now I know how the sausage is made!

Regardless, I am excited by this shift in the AAA space for brighter more readable games rather than the drab greys of the past. It’s simply more fun and engaging.

Timothy Bermanseder, co-founder of Cardboard Keep