Creating Breathtaking Game Backgrounds

The sky and background artist Tony Arechiga shared the details of his pipeline and work on Destiny and gave some tips for producing great landscapes and skyboxes.

Introduction

My name is Tony Arechiga, I currently live in Washington State. I have worked on a number of projects over the years: Epic Mickey, Sims 3 Pets, Warhammer: Dark Millennium Online, Destiny 2, and more. I’m currently working at V1 Interactive on an unannounced project. I started in the game industry as a QA tester at a company called Terminal Reality, and eventually worked my way into doing environment art on the projects mentioned above. It has been a 12-year journey of failures and success.

I got into background/sky art because I love being outside, and wanted to focus more on landscape art. I would play games and focus on all the stuff in the background and I realized that most games need non-playable background art. Most playable gameplay spaces are small, but adding set extensions creates an illusion the games are a lot larger. I became obsessed with creating terrain and distant mountains after playing Skyrim. That game really changed what I wanted to focus on. Also, Destiny (2014) had an impact on my appreciation for background art, and so I started making skyboxes in my free time.

Landscape in 3D

It really is about creating a good 360-degree 3D landscape painting. The composition is very important! You need to find the areas of the playspace that players will get a good view of the background, and make a tight composition. You want people to pause for a shareable moment. There is something about a large open vista that really makes you want to take a screenshot to share on Facebook.

Also, try to explore the outdoors if possible. I spend a lot of time in the mountains on hikes and backpacking trips just to get a good vista.

These are just a couple of reference pictures from around my house. I deliberately live in the mountains so I can access views like this on the weekends:

Scale

The scale is tricky. The best way to determine scale is to obsess over landscapes and terrain. It helps to have some sort of visual cue in the playspace that extends into the background. So if the player is standing next to a tree, and you see the same type of trees in the distance, your brain sort of plays a trick on itself, and says “Oh, that’s far away and really epic!” Also, atmosphere, value, and perspective are important. Atmospheric Fog is extremely important for creating distance. It’s good to balance the fog, sky, and terrain to have different values. It helps sell the illusion of depth, and this is something I’m still learning myself.

I look at a lot of references, and I take a lot of reference photos during hikes. This way you start to understand what a mountain in the distance should look like.

I like to turn images black and white to see how the values are looking.

Necessary Skills for a Background Artist

Being a background artist in games requires a lot of various skills. The technical aspects of making a sky can be broken down into multiple articles over time.

I think the best approach is to keep it as simple as possible, reduce, and reuse as many assets as you can. Delete out unseen polygons and crunch your textures down with MIPs. I author my textures fairly high res, but I crunch them down to as low as I can without the quality suffering. Anything you can do to help performance out! I try to place alpha cards sparingly in the environment, but this helps break up a ridgeline and blend terrain seems. Just hide as much as you can with as little as you can.  Remember to reduce, reuse, and when in doubt – fog it out.

Approach to Skyboxes

I take thousands of pictures of clouds and landscape shots throughout the year. I cobble together pieces of 2D clouds and make alpha cards out of them. I also create full 360 panoramas and just try to craft a decent composition. I’m still learning and honing my composition skills any way I can. Cloud creation is all over the place right now! I’m loving the new procedural volumetric stuff out there and well crafted matte paintings. Games seem to be going more toward volumetric clouds, but I still love crafting 2D clouds. You can make cloud cards in Terragen, Vue, Houdini, and Photoshop. Also, I usually touch the global lighting of a map to set the mood. To get a cohesive look to a map you can use post-processing and fog to get a look that has that concept art feel.

A quick example of a simple alpha cloud:

First, make a second layer and fill it with black.

Duplicate the cloud layer and paste it over the black layer. Double click on the layer and switch the Blend If drop down to BLUE.

Mess with the sliders until most of the blue is removed, and paint out the edges to make it not look so crunchy.

Then merge this layer down into the black layer and desaturate it (ctrl+shit+u).

Save out the diffuse and the alpha textures to be used in whatever engine you like. 

You can create large hero clouds, you can stack textures on a rectangular texture, you can pack textures into the RGB channels. There are so many ways to make cloud textures that it really comes down to preference, and performance. You can then paint in rim light control and add movement in the shader within Unreal. 

A couple of examples:

Animating the Background

The animation is fun! I like doing little animations to make the background feel more alive. Basically, every studio is different on how their animation pipeline works. I like really simple spline animated objects. Just a couple of looping keyframes usually get the job done! I’ve animated sun arch, spaceships, and even cloud cards. Just keep the animations simple, and they can go a long way to make the sky come to life! Most movement on clouds comes from shader work. Tiled clouds scrolling across the sky work really well. I’m experimenting with new ways to create movement all the time.

Background Pipeline

The first thing I do before I start on a background is exploring every corner of the playspace to find the best viewpoints. I then start gathering reference or look at the concept art for the space. 90% of the time the concept art will just use a photo found on the internet for the background in a scene. So I try to gather reference that fits the mood of the concept art. I have several hundred terrain pieces I’ve made over the years and I use these as a library to block out the view. I’m also an obsessive user of World Machine and Houdini’s heightfield generators. I’m constantly exploring new ways to make terrain and have way too many experiments to count on my computer. Having a library of assets really speeds up the process of creating a background. For Destiny and Destiny 2 a lot of assets were created already by the sky lead Mark Goldsworthy, and I would use what was there to create new views.  

I often do paint overs and thumbnail sketches to plan out composition. Then I will move mountains and terrain chunks around until it “feels” right. I will show what I have to the lead in charge and get feedback. Then I will adjust until they are happy with the result.

The sky portion of a background can be done in a hundred different ways as well. For Destiny, we used tons of moving transparent cards to create the sky. Each card in Destiny had to be tuned for Time of Day, and this was extremely tedious. Every aspect of the sky had to be color tuned from Sunrise to Sunset.

Currently, I’m focused on creating the static time of day skies and doing matte paintings of a sort based on photographs I’ve taken while on hikes. I have thousands of cloud photos that I have taken over the years and use these as an asset database to cobble together panoramas. I have also used Terragen to create cloud textures and panoramas. My early skybox experiments were done with Terragen and Unity.

I feel like clouds are going to be fully replaced by procedural volumetric cloud generators soon and will need little time to be created. So I will enjoy using my photographs and Matte paintings for as long as I can.

Trials of the Nine: Breakdown

Below I’ll give a really quick breakdown of one image from Destiny 2.

This sky is deceivingly simple looking but had its challenges. The midground is World Machine pieces, the horizon is an additive fog card that blends into the color dome. I set up a 32-bit color gradient that tiles and colors the fog in the environment. The planets are spheres made in 3ds Max that were baked down to an alpha card. I do this so you can blend the planet into the atmosphere and really get a soft blend. It helps push the planet into the distance and its art directable (in case the lead wanted to see more or less of the planet). The planets are attached to a spline animation that rotates around the playspace. Since the planet has a normal map, it is lit by the sun as it rotates around the environment. The bloom on the sphere is animated over time as well and gets brighter and darker as it moves. This a very simplified process explanation, but that is pretty much it.

Tony Arechiga, Sky Artist

Interview conducted by Kirill Tokarev