Florent Tunno gave a talk on his recent relighting experiments in Unreal.
Florent Tunno gave a talk on his recent relighting experiments in Unreal.
Introduction
Hi everyone, my name is Florent Tunno. I am a young graduate Environment and Lighting artist from France.
5 years ago I decided creating environments for video games would become my full-time job. I worked on various student projects during my 5 years of study, from 2D mobile game to full PS4 3rd person game. I quickly focused on modeling, texturing and lighting because I wanted to graduate being able to produce a complete environment by myself.
My most recent projects are focused on lighting because that’s what I want to do in the video game industry.
Re-lighting
I chose these scenes because I wanted to improve my lighting skills. As all learning scenes from Epic are almost 100% ready to use, I used the scenes to focus on lighting, composition and post process.
It wasn’t my first attempt at lighting using Unreal Engine 4 but I still learned a lot doing these projects. Relighting scenes are a very effective way to train, learn and improve saving a lot of time not having to create all the assets and textures.
Principles
There are two ways you can look at lighting for video games: a technical one and an artistic one.
Technically speaking, it’s a matter of UVs settings, lightmap resolution, memory constraints, and guiding the player through the level (you can’t have a too bright or too dark area, or the player will feel weird about it).
With the technology available today, you have different ways to light a video game. You can use dynamic lighting, that allows you to have real-time interaction with lights, but at a performance cost. The other way consists in using a full or partial baked lighting. This method allows you to use Global Illumination: you can tweak how light bounces on the environment, shadows, and light propagation are more accurate, smoother, more realistic overall.
[Screen dynamic vs Baked lighting]
When I do relights, I usually start by gathering references from games or movies, but also from photos! Because modern engines are able to replicate how light and materials react, like in real life, it’s essential for any video game artist to understand how it works. You have to understand how PBR workflow works, why does a light ray bounce on an object, what light temperature can bring to your scene… Luckily for me, I’ve learned how light physically works in high school, so it wasn’t completely new for me when I got interested in lighting for video games.
When I am done gathering references I kill all existing lighting from the scene I am relighting, that includes deleting all lights and Lightmaps.
Lighting isn’t just putting lights into your scene, tweaking the settings, bake and voilà. You have to prepare your scene to be “Lighting ready”.
First, have to start placing Lightmass Important Volumes, Lightmass Portales and boxes or spheres reflexion capture. Then you have to set up all your meshes lightmap size. UE4 has a great tool called Lightmap density. It’s really helpful to get the right lightmap size for each of your assets.
Then you have to think about level design and environmental storytelling. I’ll talk about it later.
Finally, tweaking Lightmass settings is a must. Depending on your hardware and your level size, you’ll have to tweak each setting to get to a fine result. If it’s a portfolio project, don’t hesitate to bump up the settings!
Lightmass settings from the Bunk scene
To begin with, you have to know being a lighting artist means that you have to mix technical and artistic skills together.
You have to remind less is more. Don’t try to use a bunch of different light, start with a directional, look how it interacts with your scene, then add point or spotlight to highlight details, or indicate where to look at when people will take a look at your work.
Lighting a scene takes time, don’t rush it, as I said before, Lighting can break your scene but it can also make it shine!
When you start learning lighting, tweaking settings can be boring at some point but the more you’ll do it, the less time you’ll spend on it. In the beginning, you’ll search for long minutes where to look at, but with practice, it will become natural for you.
Don’t forget creating a video game involves faking a lot of things. Don’t hesitate to bump up values or add more lights to an area if you think it seems too dark. Lighting for video game isn’t only a matter of realism, you have to remind that people will play your game. You can’t have a very dark area because it’s “realistic”, the player has to see where he is going. And if your scene is too dark, players won’t have the possibility to take a look at the awesome work your team produced!
A good point to start at learning lighting for video games is to watch Epic’s awesome tutorial videos: