Benefits of Procedural Materials

We’ve had a chance to talk to Bradford Smith – a talented material designer and 3d artist, who contributed a lot to the Uncharted series. He did an amazing lecture at GDC16 and today we present to you a little interview with Brad about various ways you can approach material design with Substance Designer and the role that materials play in video game production.

Introduction

I went to Ringling College of Art and Design to study Animation. The Game Art BFA program at Ringling College brings our feature film aesthetic to games and is focused on providing students with the professional artistic skills necessary to create compelling and believable interactive experiences. Upon graduation I was offered a texture artist position at Electronic Arts Tiburon in Orlando Florida with a number of other graduates. It was a pretty amazing first gig actually. At that time I got hired, Disney had closed their Florida animation studio, releasing some incredible talent; some of whom came to EA as well. So here I was my first day on the job, as one of the only texture artists on research and development for the new Madden NFL Xbox 360 and working with some amazing people from both games and film. I worked there for over 6 years and I owe a lot of my work­related values and process to my time at EA, especially those early transformative years. Since then, I’ve been at Naughty Dog for over 5 years after falling in love with Uncharted 2. That game really struck a chord with me. It was the first time I had really seen incredible narrative, design, and gameplay all rolled up together in an entertaining package. When I saw an open texture position during the production of Uncharted 3, I knew I had to go for it. Most recently, I’ve also taught a few 3D production courses at Otis College of Art and Design here in Los Angeles.

Material Production

I’ve got much to learn myself, and it’s the incredible work of others that keeps me inspired and moving forward. I love what Albert King said to Stevie Ray Vaughan during the recording of In Session: “… the most important thing: the better you get, the harder you work.” To me, that perfectly summarizes the role and responsibility of a lifetime student.

“… the most important thing: the better you get, the harder you work.”

As for starting any environment project, value is paramount, and color is a close second. There are certain value conventions that are very well defined and established in landscape painting for instance. Start with large compositional value zones and then establish your local colors and their value ranges. If the piece is animated, then subject motion is an equally if not more important factor in leading the eye. As early as possible you also want to communicate your lighting and composition goals by blocking in cameras and lighting. These things should ultimately inform the development of the environment, ensuring that all these components work well together from the beginning. Traditional principles like these are why some of the most recent and beautifully stylized games are so visually successful despite being very simply shaded. As much as I love microfacets and index of refraction, the truth is that surface response varies wildly across like materials and is often subjectively set to taste or to the fit the limits of a given renderer or engine. With that said, if materials don’t react to light properly in a hyper­real environment, then it could definitely negatively affect the viewer.

When setting out to achieve consistent and high quality materials, it’s important to develop them in a neutral lighting environment, test them in extreme lighting conditions, and try to avoid compensating for those additional conditions or camera settings if possible. Whenever I start out creating base materials I always setup calibrated lighting conditions, and set up my cameras to be as neutral as possible and to expose for local value properly.

Advantages of Procedural Materials

For me, the main advantages are flexibility, modularity, and reuse. Procedural materials can also allow for faster workflow iteration over time (the initial cost of creation is still there, but updates can propagate across assets and variations can be created incredibly fast).

Procedural materials can also allow for faster workflow iteration over time.

A procedural material is essentially the description of the authoring process. Instead of saving the final texture results to disk, you are sort of recording the creation process. You can also provide input parameters into that recorded process in order to modify the results or even completely change the end result, sometimes in unexpected and interesting ways.

Just like any good shared library, a material library, procedural or not, can help studios in a number of different ways. Crafting material libraries ensures consistency and quality across large areas of the game, if not the whole game. If these libraries are also procedural and dynamically linked, studios can gain huge amounts of flexibility and iteration power, all while allowing for customization by the individual.

3d­ Qualities of the Materials

I would say that 90% of my textures are fully procedural these days. I still sculpt a fair bit in ZBrush though, mainly for really detailed architectural textures or interesting patterns that I need to layout by hand. I then finish those textures off in Substance Designer by adding surface details and generating material response maps.

I would say that 90% of my textures are fully procedural these days.

When I’m working on fully procedural textures, I actually use a lot of my own custom nodes that are built around artistic principles or try emulate things I have traditionally done in ZBrush or Photoshop. I try to be as explicit as possible with my procedural work and build re­usable global tools in the process of making textures. Modularity and reuse are key concepts in streamlining your Substance Designer workflow. You don’t necessarily need your own node library, but I think that it would be hard to advance the quality and turnaround time of your work without one.

Material’s Look

Throughout the creation process I’m constantly evaluating my textures as I go. If the primary and secondary forms in my height and normals aren’t working, then there is little need to finish out the details. So I’ll always export a rough first pass in order to evaluate the normal map in game.

Balancing scale, level of detail, texture quality, and rhythm are all regular challenges for texture and material artist.

My approach for surface materials is very similar. I like to evaluate surface qualities in isolation, and then create richer responses by blending them together. A simple dusty painted surface may actually be made up of 3 or 4 carefully set up base materials.

Details

Balancing scale, level of detail, texture quality, and rhythm are all regular challenges for texture and material artist. Blending together just the right combination of forms and frequencies of detail often requires iteration and experimentation. Some of the things that I do to overcome those challenges are:

• Work in isolated layers (primary, secondary, tertiary form, surface details, etc)
• Develop these layers in isolation and then experiment with combining them together in different and interesting ways
• Focus on the most important surface quality or qualities that effectively describe a surface. Boil a surface down it’s essence, and back up from your work once in a while to avoid falling into a “detail trap”.

Experimenting with Materials

Persistence. I often don’t get it right on the first shot, but it’s important to keep trying and to continue to narrow your focus. That’s why I try to stay loose at the beginning of a project, focusing on primary forms, and local value and color. Also, keep and recycle your garbage if you can. I’ve often used sculpts and procedural nodes in production that were terrible by themselves, but created magical results when combined with something else. Don’t be afraid to get out of your comfort zone and experiment a bit. And most of all, don’t get discouraged or self­doubt when something doesn’t work out; just change your trajectory.

Story with the Details

Besides enhancing believability and grounding the player, materials can play a subtle but vital role to both narrative and gameplay design. Textures and materials can often tell stories by themselves, and enhance the world the occupy. Who built this world? What materials did they have at their disposal? Did they decorate their environments with murals, carvings, or sculptures? If so, what is the purpose? What is the climate like? These are all questions that textures and materials can help suggest. Surface quality really breathes life into models, and it’s important the two work well in harmony and serve each other.

Besides enhancing believability and grounding the player, materials can play a subtle but vital role to both narrative and gameplay design.

Materials can also help enforce visual language for gameplay. You see this all the time in adventure and racing games for example. The combination of shapes, color, value, and rhythm all come together to help guide the player through the environment.

Bradford Smith, 3d artist

INTERESTING LINKS

APPROACHING MATERIAL PRODUCTION

WORLD & CHARACTER CREATION IN AAA AND INDIE GAMES

INTERVIEW WITH MAKEHUMAN: THE FUTURE OF 3D-CHARACTER CREATION TOOLS