Lighting Questions with Omar Gatica

The Art of Lighting for Games Course

Thank you to everyone that attended the most recent webinar with Omar Gatica. In this webinar, Omar Gatica, Principle Artist at Infinity Ward, will share his experiences as a lighter and his overall workflow & process on achieving beautiful & practical approaches to in-game/realtime lighting. Click here to see the full webinar replay and take a look at the questions and topics covered below.

1. What software do you use for lighting?

• Professionally I use a proprietary game editor called Radiant.
• In my class at CGMA I use Unreal, as it is easily accessible and produces great results.
• However I stress that this is only a tool. I really try to emphasize the thought process over proficiency with any given software.

2. What would you say is the major difference with lighting for real time vs pre rendered?

• Well, there are many differences, but first let's take a look at what the two methods have in common. Both games and film create the illusion of movement through playing a sequence of still images at a fast enough speed that it fools the human eye into thinking it is one continuous moving image.
• Now consider how long it takes to render a single image using a software or GPU renderer.
• It depends on the size, quality, and complexity of the image.
• The renderer may be drawing geometry and materials, raytracing reflections, calculating global illumination, sorting transparencies, computing sub surface scatter and ambient occlusion, etc.
• It could take half a minute, or several minutes, or in some cases hours just to render a single frame.
• A game engine also has to render images consisting of geometry, materials, lighting, VFX, and many other components. However any given game has to render each image 30 or 60 times each second.
• Rendering a compelling image at that speed, with the limited resources of the hardware is what defines the the biggest challenge in runtime rendering.

3. How long does it take to light a scene?

• I always say that I never finish lighting a level, I just run out of time.
• Levels are usually in production for several months and they are a collaboration between many departments and disciplines.
• I’d guess that in general, our multiplayer levels are in production for a 2 to 4 months, while single player levels tend to take a bit longer. On average 4 to 6 months.

4. What is your favorite aspect of lighting and why?

• That's an interesting question. There's many things I like about lighting,
• Over, it's really cool to be able to have such a large influence on the mood, or look of the level.
• I really enjoy lighting night time scenes, with a lot of local light sources. There's just a lot of opportunity for fun moments and high contrast interactivity.
• Sometimes, I have days where I really enjoy just doing some of the more tedious tasks. it's nice to have days where I can just put my headphones on and just lay out Reflection probes, and let my mind wander.
• Lately I've really been into all of the sky photography that we've been doing. I've been learning a lot about making HDR images and panoramic photos.

5. Can interior designers use these techniques?

• I suppose one could, but what we look for in lighting for games is to define mood and gameplay through lighting. Where it seems to me that a designer is looking to fill out a space in a way that is functional and inviting to the occupant. I think that many times those two ideologies conflict.
• Having that said, I think that artists learn and grow more in their own field when the study other disciplines. In my opinion I think all artists should study other forms of art.
• Honestly, I think it would be very useful for a game lighter to study interior design.

6. What are some ways to ensure balanced lighting while retaining sufficient contrast?

• It's really something that you build up as you work on a level. Lighting is like anything else, you block out your values and you continue to refine and polish as you iterate.
• I always look for, and try to be conscious of gradients, and the transition of my light in my scene.
• I make sure that I have proper reflection probes to sufficiently and reasonably represent the hilights in my scene.
• And most importantly I work closely with my fellow game developers. We exchanged ideas and communicate our needs. I think the best pipelines are the ones that are the most collaborative between artist designers and engineers.

7. Do you think lighting for games is harder or easier as opposed to lighting for film?

• The two are different and I think each discipline has its own unique advantages and challenges.
• Lighting for games is difficult because you are always dealing with limited resources.
• Additionally the culture of game development is more on the side of “If you see something that needs fixing, go and fix it”.
• Finally its true that game development cycles can be brutal depending on the project.
• I think that lighting for film is more constrained in the creative freedom that any given artist has.
• I also think that culturally speaking, you are expected to get through a predetermined amount workload and not go outside your proverbial box.
• This just has to do with the fact that films are much more produced budgeted and planned out.

8. How do you achieve a balance between dynamic and baked lighting?

• Ideally I want as much dynamic lighting as possible, but due to the limitations of the game, I'll have to make concessions.
• My basic approach is to block out the most important lights with dynamics, then use static lights to fill out the area.
• I try to use dynamics as my key sources, and statics as low intensity fills.

9. How do we use volumetric light efficiently in video games?

• Once again, this depends on the context of the scene.
• In my experience people tend to respond more favorably, to what I would consider a more dramatic, or somewhat exaggerated use of volumetrics.
• So my approach is usually to put them in a more conservative values, and then as art is wrapping up on a level, I tend to push them a little stronger for mood.

10. What's the trickiest part of lighting for you?

• For me, the trickiest part is pushing out of my own comfort zone in my work.
• To try new things, and to not be afraid to fail.

11. Have you got any tips to enhance the scene you have build? How do you take the attention of the player to a point in a fluid and natural way?

• This is really more of an iterative process where I sculpt the lighting to how the level design is shaping out.
• I'm always looking to lead the player through will be considered the golden path.
• I'm always looking to lead the player around corners or invite them in the spaces where they should be going.
• Similarly I tried a theme danger areas with a consistent color so that the player Associates certain colors are moods with what is happening in the game play.

12. How do you make the lighting and shadows work well (reacting in a believable way to various characters or items in the scene) in all areas of each scene given such large environment spaces and major camera movements? Does the lighting move with the camera?

• Well once again it is an iterative process. I'm constantly building up the lighting and making adjustments based on what the environment team is doing, or what the designers need. We frequently play through the level and I make sure that I am aware of and supporting any narrative beats or specific moments of action.
• I don't think anyone goes into a level with a blueprint of how they're going to set all the lights up and where everything is going to go. We get a piece it has a mood it may have concept we may have to pull our own reference. but as you work on a level it starts to develop its own personality and character and it a lot of ways I think that the level tells me what it needs.
• I develop a relationship with all of my levels and I do my best to understand their strengths and their challenges. I try to support that as much as I can with my lighting choices.

13. What was your career path? How did you end up working at IW?

• Well my career path is kind of taking me all over the place. I got out of art school in the early to mid-2000s, I then started working in visual effects with the goal of getting into film. But like any artist I had to get my foot in the door, and I found myself hustling to take whatever jobs I could.
• After a few odd jobs in commercials and vfx, I found myself working at a company called NCsoft doing pre-rendered cinematics for a game called Guild Wars. I was hired as a generalist but I ended up helping on lighting as that is where they were short-handed. We made some pretty cool cinematics.
• After NCsoft I was picked up by Activision Central Tech, where I worked on some internal cinematics, some R&D stuff, and some marketing material.
• After bartier year I moved on with the idea to get back into visual effects and film. I work for a few commercial houses and did some work on a couple of small movies.
• Around 2007 I was recruited by Naughty Dog. They needed a lighter for a new project that they were about halfway through called Uncharted. That led to me working on the first 3 Uncharted games. It was a great experience and I still have a lot of friends from and still at naughty dog.
• After Naughty Dog I went on to work at neversoft. They were starting to work on what was for them a new chapter, in the Call of Duty franchise. I have a lot of great memories of that studio and my time there.
• Around 2014 neversoft shutdown and we merged with Infinity Ward, with whom we have been co-developing the previous game.
• I've been at Infinity Ward since and had the great opportunity to work with a fantastic team amazing artist and incredible engineers.

 

14. How do you calculate amount of lighting when accounting for clouds, bad weather effects, and/or use of heavy f/x from Game??

• Professionally, I work with image based lighting for the GI solution in our game, and we are capturing our own data. That means that as long as our sky and sun are calibrated to the measurements that we record in the field, we know our lighting values are correct.
• There is also a lot of communication between departments on our game. It is quite common for me to talk to environment art or VFX regarding our approach to any given problem. It is very much a collaborative process.
• As in all things, we inevitably modify and embellish our values as the needs of art, design, and narrative dictate.
• In my class, we use free HDR images for our IBLs, and we follow the same principles, but we simply eyeball the values. Most of the feedback that I give to my students is from an aesthetic perspective, as opposed to a technical one.

15. Is photography important to being a better lighter?

• Absolutely. As games become more and more physically based,  having a background, and an understanding of how cameras and photography work is great.
• In my specific case, we are investing a lot of time and effort in to capturing HDR panoramas for use as sky boxes and IBLs in our game. Photography plays in important role in what I am doing as a lighter these days.

16. Who are artist you look up to for lighting references?

• I find much inspiration in the work of my co-workers and artist that I am fortunate enough to work with. In my view, Art does not happen in a vacuum, we constantly learn, grow, and change our perspective based on the influences of our environment. I am fortunate enough to be in an environment with many phenomenal artists.
• In my short time as a teacher, I have found inspiration in the work and passion of my students. I like to think that I learn from them as much as the do from me.
• Some of my personal Favorite artists are,
• Classic Painters: Jean-Léon Gérôme, Georges de la Tours, Rembrandt, and John Singer Sargent.
• Filmmakers: Stanley Kubrick, Steven Spielberg, Ridley Scott.

17. What's your favourite tool for lighting?

• That's a question that sell them gets considered as lighters generally have to light with whatever game editor or engine that the specific project is using. For example I work in a editor that is exclusive to Call of Duty, but it's basically a descendant of quake.
• I miss working in Maya just because I've used it for so many years and it's comfortable for me. Recently I've have really enjoyed using the Redshift renderer as it plugs into Maya, for my personal work.
• And finally I really think that Unreal is a phenomenal tool. It is incredibly accessible, and it can almost effortlessly produces amazing results.
• I also think that they have made incredible strides in making it user-friendly and accessible to artist that don't have a programming, scripting, or technical background

18. do you have light parented to the characters other than a flashlight or torch-- i.e. like a 3 point light setup just following the character around.. or is it all static in the environment?

• Generally we light gameplay environments as set pieces.
• We have dynamic lights but they don't follow the player around. They are simply interactable with the player.
• We can script or automate certain behavior on a dynamic light.
• However, other than in cinematic cutscenes or the fore-mentioned flashlight/torch example, we do not follow the characters with lights

19. If baking is still a necessity, how to handle baked elements with dynamic objects in the same scene.

• it depends on the nature of the game. Different games have different methods of rendering the two major camps or what we call deferred, and forward rendering but in reality lots of engines use a hybrid method.

20. How do you decide how much of the environment is being lit at any one time, as illumination is dependent on scale and how everything interacts, for it to be efficiently rendered on a console?

• First off, our game (like all games), has a system for calculating the players visibility at any given point and culling out that which is does not need to be rendered or that which is not in the camera's field of view. This calculation is done at compile time and that data is stored for use in the game.
• Secondly, we try to design our levels in a fashion that helps our occlusion/visibility calculation. This is why you never (or rarely) see a level that has a really long vista where you can see all or most of the game play space at once. We are conscious of how much we are asking the engine to draw at any one given time.
• We have a priority system which dynamically chooses which shadows to prioritize and update based on the players distance to them.
• We also have an LOD system for our shadow maps.
• And most importantly, when we work, we are conscious of the placement and complexity of our lights. We have debug modes (just like UE4 does) that allow us to visualize the performance of our lighting set up, and we make deliberate choices based on that debug information.
• Lastly, all of our levels go through and optimization phase, where they are audited for framerate and performance.
• Remember that when we are talking about a level performance, it is not just an issue of lighting, but it is a holistic look at the entire requirements of the level. That includes Geometry, Materials, Lighting, VFX, Transparency sorting, Audio, UI, and many others. So each level is considered on its own merit and needs.

21. What's the best cheat you found so far for lighting?

• I’ll let you know when I find it. :)
• I believe that what makes anyone good at anything is practice and experience. That is especially true for artists.
• Education is very helpful in accelerating one's understanding of the process and tools and I highly encourage it. However I am not saying that to sell classes. And all of the classes in the world don’t matter if you do not apply and practice what you have learned.
• In my opinion, there is no shortcut for experience.

22. Once you have the basics of a scene's lighting setup built out, what process do you take to revise upon that scene outside of feedback from team members.

• Well, I have to point out that feedback from team members is huge and one of the most important resources I have.
• There is always input from Art Direction, and Concept.
• I stress that reference is key whenever you find yourself losing perspective on what you are trying to achieve aesthetically.
• And finally, my own personal sensibilities are an amalgamation of all of the art, movies, games, and experiences that influenced me up until this point. I find that sometimes I rely on that more than I should.

23. What are challenges on working on the different games and how to approach them.

• It's really dependant on the game. There are lots of considerations in pipeline and workflow

24. Could you give us an overview of your course?

• My course will demonstrate a practical approach to in-game / realtime lighting, within the context of a production pipeline.  We are working in Unreal Engine as it is an easily accessible platform. However the workflow, and techniques will be presented in as much of a software agnostic format as possible. This is because, many studios use either proprietary, or heavily modified engines that are unique or exclusive to that studio's pipeline. These techniques will apply to any contemporary pipeline. My course will guide students through weekly examinations of different lighting scenarios, environments, and gameplay styles. I will demonstrate how I approach lighting them, and the workflow that I use to get them from a conceptual state to a working playable level. I will also provide all of the necessary scene files for each week.
• I invite you to visit my class page on the CGMA website, or contact CGMA directly for more details.

 

25. What are the differences between lighting for ND and IW

• Well it's been a while since I worked at Naughty Dog. They have great tools and great artists and engineers.
• I think the biggest difference in lighting between the games, is that Naughty Dog games are in 3rd person and at IW our game is in first person. There are slightly different considerations taken into account regarding the level of detail that you are rendering when you are in 1st or 3rd person.
• On older iterations of CoD we had to make certain graphical concessions because our game is running at 60-FPS (frames per second) while at the time Uncharted and Last of us ran at 30-FPS. That meant that we literally had half the time to draw each frame on screen.
• These days the 30 vs 60-FPS argument is not as strong as hardware is improving and many more games are also running at 60-FPS and boasting a very high level of rendering.

 

26. Which engine is your favorite for lighting and why?

• Personally I think it would be Unreal Engine because it is so accessible, and it produces such great results.
• I have worked with several proprietary engines, and each had their unique strengths and weaknesses. I find that the particular engine that a studio uses is less important, and what really matters is how much engineering support they have to make improvements and support new features.
• It is always great when a studio is committed to supporting and improving their rendering pipeline.

 

27. Is your course geared towards beginners or more advanced students?

• My class is geared towards students that have an understanding of working in 3D.
• They do not need to have a background in lighting,
• Students should have a basic understanding of light types. (ie. Spot /Omni/ Directional lights).
• Students should also have a fundamental knowledge of the basic properties of lighting. (ie. Intensity, decay, cone angle, etc.)
• My class focuses on the thought process and the methodology for approaching the lighting of environments.
• I really try to cover these concepts in as much of a software-agnostic way as possible.

 

The Art of Lighting for Games Course