The GDC clip is basically him talking on others people work completely unrelated to what he's supposed to sell. High five!
Ashley McKenzie discussed the way he conquered lighting in this detailed virtual scene.
Hello, my name is Ashley McKenzie, I am a lighting artist in the games industry from London. I have been avid gamer from quite a young age so I’ve always known this was the industry I wanted to end up in. I did my bachelor’s degree in computer games with a specific focus on art at London Metropolitan University. I graduated in 2011 and from there I spent two years working in quality assurance at SEGA whilst improving my portfolio before l landed a trainee lighting artist position at Rocksteady Studios in North London.
I worked at Rocksteady Studios over a period of two years on Batman: Arkham Knight and the subsequent DLC with a team of incredibly talented artists, going from trainee to a junior role before heading to the Manchester studio of Cloud Imperium Games. I spent a year at CIG working quite closely with all three art directors and the engine team contributing to both Star Citizen and Squadron 42. I am now back in London working at Splash Damage on Gears of War 4 DLC maps.
UV Light Bedroom
I find the mood and overall aesthetic of UV lights in conjunction with vibrant coloured neons really appealing, there’s something quite retro about it that’s always intrigued me. When I was younger I used to visit Camden quite frequently and there are some quirky shops there, one of which is a place called Cyberdog that is lit almost entirely by ultraviolet which I found really cool. Even the Batman and Robin film from the 90’s I thought the look of the UV gang and their den was awesome. I also think the actual science behind UV light and how it reacts to certain surfaces and materials is fascinating too so I knew it was something I wanted to try and emulate at some point in a game engine.
I wanted to complete the night time version of this scene first as it allowed me to work out which elements and surfaces would be glowing and reacting under UV light. To do this I looked a little further into the science behind UV light to be sure I had an accurate representation in my scene and specifically in the materials. I felt that the day time version would fall into place more naturally that way but I always had both versions in mind from the start.
I think getting the directional light, ambient and fog levels right at the start are crucial to the rest of the scene. Although the fog is quite subtle in both versions without it the whole scene can start to look very unrealistic and ‘gamey’ so I spent quite a bit of time adjusting that at the start and iterating on it throughout.
The first thing I did was to work out the angle for my directional, this involved playing with the size of the moon and the overall intensity of the directional itself. It needed to be just enough that is was visible in certain shots but not dominating to the scene in any way and pulling away from the focus of the interior for the night time version. Having a few trees blocking some of the
light and creating long shadows helped with that quite a bit. I also chose to go with quite a dark sky dome for this scene just as it helped with the overall read of the interior as there wasn’t a noisy backdrop pulling away focus.
Then I moved on the placement of the key light in the scene. I pulled quite a few reference images trying to decide on fixtures for the actual key light, whether to go with multiple fixtures in each corner of the room or one dominant in the centre. I decided on a single dominant fluorescent tube light in the end as it allowed me to have a focused point of intensity on the bed. That made more sense and helped me to use the shadows as an opportunity to make the other glowing elements in the room visibly pop a bit more.
After placing the key light and the secondary glowing elements I needed to add some fill lights. As this was quite a stylized piece I found it best to go by eye as opposed to being totally physically accurate. I used quite a few point lights and spot lights in areas where I wanted to fake more bounce with the “inversed squared falloff turned off” and the “min roughness” set higher than usual just to prevent the fill lights creating too much specular hit. There is also the option to turn up the “indirect lighting intensity” on any light but I’ve found this way a lot more efficient for this scene as it allowed me to pick out exactly where I wanted more bounce.
I found with this scene that allowing certain assets to use an additional lighting channel as opposed to just the static really helped me to give certain elements a better read. This was mainly used for the posters in the room, which I set up additional spot lights to affect only those channels.
For my reflections in this scene I used two box reflection capture actors for the interior and one sphere closer to the window.
Finally, I created a colour lookup chart in Photoshop. This involved taking a screenshot in editor and then taking that into Photoshop and using layers to adjust contrast and subtle colour correction. For me personally I think of the colour grade as that last 10% of the scene. I use it to compliment the lighting and mood I am trying to set so it is the last thing I do for any scene. Bringing in a colour grade any earlier would mean you are lighting against it and trying to compensate for colour and contrast adjustments set in the lookup chart.
I think the biggest challenge for this particular level was getting the intensity of the key light and bounce light working together. It also went through few iterations for the materials on the walls and floor for this level to get for this level.
I have to thank Jimi Thornberg and Jack Walker for their awesome feedback when doing the night time version of this level too.
The night time version was definitely the most labour intensive part of this scene, but also the most fun as it was a challenge. This required me to create a lot of bespoke emissive textures and think about the placement of the glowing sources to create the best scene read. It would have been easy to go too far with this and I did actually have quite a few paint splashes and glowing footprints on the ground which I later removed due to the noise they were creating.
As this scene was mostly inspired by my childhood I tried to incorporate that into the glowing elements, I added very subtle glow to the posters and skateboards and also added a glowing autograph to each of the photographs on the left. The colourful designs and logos allowed me to have splashes of colour in a mostly dark scene.
For the neons attached to the bookshelf I found that the bake from emissive feature was the most effective way to achieve the look I wanted from these particular lights as they are essentially just cylinders for the geometry.
I set up with the fairy lights with a point light for each particular bulb to create a small hot spot on the wall. Then after that I added an additional point each light to each bulb to create a more gradual falloff. As almost every light in this scene is a static light I did not have to worry about run time cost as it is all baked. I used this same technique for fluorescent tube light on the ceiling, except with this I used multiple spotlights instead of point lights to create the hot spot.
Overall all the glowing elements of scene went through multiple iterations and balancing, I tried to emulate that with the fabrics too, giving the bed sheets and pillows a subtle glow as they would in the real world due to the phosphors.
Being a different time of day I wanted the general mood of the morning version to feel very different to the night time, I wanted it to feel like a warm tranquil summer morning.
With the morning setup I wanted to keep this as simple as possible, I think less is more was definitely the case here. I am only using three lights for this scene, a directional, skylight and one point light on the ground in the centre of the room to fake some additional bounce light. The point light itself has its source radius turned up slightly which helps soften the shadows a bit, this was needed because I was using this light to fake indirect light as opposed to being a direct light.
I started with the skylight for the morning version as I wanted to get the ambient colours right first. The HDRI map I chose for the sky dome was a good start but before applying it in editor I gave it a bit more saturation and contrast in Photoshop, this helped to get a nicer gradient of colours when baking the sky light as opposed to the one colour I was getting before.
With the directional light I chose to use the standard colours instead of a temperature approach that I would usually use for a standard daytime scene. I did this because I wanted to push a bit more warmth into the scene and give it more of a pink hue to work a bit better in conjunction with the skylight.
To really get that extra contrast in the scene I played around with the lightmass settings in Unreal. I found setting the static lighting level scale to lower values with increased samples in the config files really helped to get more refined and realistic shadows in the corners of the room.
I think if I spent more time on this scene I would have liked to use more decals to give all of the materials a bit more specular variation.
I also think it would have been cool to have some posed characters in characters in the scene to try and emulate how they would light under these conditions.
I would also have liked to play around further with lightmass settings in Unreal but due to the increased build times as a result of this, it wasn’t really an option right now.
The Importance of Light
Absolutely, I think lighting is the biggest visual change you can make to any scene and you can completely change the mood of a scene with your choice of colours and placement of your lights.
You see it in film too if you look at colour scripts, at key points in the story there are very conscious decisions to use a specific set of colours to covey a certain mood or emotion.
We do the same thing in games too, just with the placement of one light we can completely change the focal point of a scene. Doing this we can guide a player along a specific path, contributing not only to the visuals but also the gameplay of the level.