Abandoned Hotel | Environment, Atmosphere, Lighting and color grading

Step into the Abandonded Hotel with Sourabh P Hamigi as he walks us through the creation of this well crafted scene and breaks down his process, giving you an insight on materials, decals, camera settings, particle systems, as well as tips and tricks to improve the lighting and atmosphere in your work.

Introduction

Hey Everyone! My name is Sourabh P Hamigi and I’m currently working as a Lighting Artist/Technical Artist at Avalanche Software, WB Games on an unannounced project. 

I’m originally from India, currently staying in Salt Lake City, Utah. Before coming to Salt Lake City, I worked as a freelance photographer for a few years after I worked at a company called Byjus that makes educational games. I worked there as a Game Designer and Technical Artist.

The first game I ever made was probably back in 2004-2005, where I used the infamous GameMaker to make a small 2D car racing game. 

I never had any formal education in game development before coming to Salt Lake City. I have always relied on self-learning ever since I was a kid. In 2018, I published a game called Fireflies on steam that I developed myself. My undergraduate degree in computer science helped a ton when it came to the programming aspect of the development, while my experience in photography made way to the artistic sensibility in video games. 

With that being said, I was naturally fascinated with lighting in games as a result of photography – and that’s how I eventually stepped into the world of game development as a Lighting Artist/Technical Artist.

In this article, I’d like to breakdown the process of how I approached the scene ‘Abandoned Hotel’.

The Project

I’m a huge fan of Naughty Dog, especially a big fan of The Last of Us. I wanted to work on a piece that resembled the world of The Last of Us. The abandoned hotel project was a result of a semester long Environment Art class, where each student was supposed to pick concept art and create an Environment based on that. I picked a concept art called ‘Dystopia Hotel’ made by a very talented artist, Kenny Jia.

Pre-Viz

When I approach lighting any environment, I always go through the process of gathering references, finding the right composition for the scene and the mood I want to convey with colours and lighting. Lighting can either make or break the scene and trying to nail the atmosphere and mood can be a crucial factor in selling the environment that one makes.

Since I was creating an Environment based off a concept, my main composition and the kind of mood I wanted to convey through lighting was already chalked down. Finding the right framing, establishing guiding lines in the Artwork, listing the hero assets that need more focus, finding the focal points in the scene are very crucial before I dive into creating/lighting a scene.

Workflow

After I was done with my pre-viz phase, I jumped into Maya to blockout the scene and get a feel of the environment, so I can pace myself over the coming weeks. I used the door in the scene as the reference for dimensions. I blocked that out at 7 feet tall and modelled everything else around it. 

Materials and Texturing

After iterating on several blockouts, getting feedback from my peers and jumping back into it, I started working on materials and textures for the scene. I decided to use Substance Designer for creating materials for the walls, decals and the ceiling. I used Substance Painter to texture every other asset in the scene. I also used Substance Designer to make some of the maps for texturing the props in Painter.

Materials in Unreal Engine

All the materials in the scene are derived from one or two master materials. There are several advantages for approaching the master material workflow in UE4:

• Avoids duplicate shader code, as all the instances are derived from the same master material/shader

• It’s easier to add functionality to all the materials in the scene. All we must do is change the master material

• Easy to backtrack if there is any problem with the material. Since all the instances share the same master material, we know if something is broken

• Just cleaner to work with in a large team. It can help avoid everyone getting into the engine and creating materials for the props. Instead, one has to just create an instance from an existing master material

Lighting and Atmosphere 

I have seen different ways of how artists approach lighting scenes. Everyone has a different process and different approach and I’m going to talk about the steps I take and the reasons for why I do it that way.

1. Checking PBR values: Unreal uses the Metallic/Roughness workflow, so in short if the maps don’t have accurate values, things can go wrong quick. This process involves checking all the maps – Base Colours, Metallic values, Specular Values etc. PBR shaders in engines are written to mimic real-world light physics. For example, objects in real world which appear GREEN, is because of a phenomenon where that surface absorbs all the wavelengths of the incident light except the GREEN wavelength.

2. Contrast: Having Base Colours which are PBR correct is important as this impacts lighting. If they’re not this can really mess up the way material interacts with light, especially for metals that either too dark or too light. The values and saturation of Base Colours can create unintended contrast in the scene and draw viewer’s attention to those materials. Below gives an example of how Base Colours can have an impact in creating contrast in the scene. Another way of looking into contrast is the luminance values of the pixels. That is, how bright a specific portion of the scene. Apart from contrast in colours, contrast in luminance values helps draw viewer’s attention too. (Note: Dielectric materials range – [30-240] sRGB, Metallic materials range – [186-255] sRGB)

3. Skylight: Sky is one of the biggest factors for the atmosphere and lighting of a scene. Especially if it is an exterior scene or there is good influence of the sky on an interior. Skylight in Unreal is basically an actor that captures the colours and luminance values of the sky and projects it as lighting. I usually use an HDRI for static scenes such as the one above. After I have my HDRI, I make a skybox material and bake scene with a static skylight.

4. Directional Light: After I have the skylight bake looking good, I bring in the directional light and I bake the lighting again.

5. Painting with Lights: At this point we have a good base for lighting. Now we can dive into the scene and use point lights, spotlights etc to start ‘crafting’ the scene – creating focal points, painting highlights, tweaking the colours etc.

6. Adding Decals: Decals can help add additional life to the scene. They are cheap to render, easy to make and can help break up patterns and help with the environmental storytelling. I used two kinds of decals for the scene:

PBR decals: These are basically like the surface material. Material will take in all the pins – Base Colour, Specular value, Roughness map etc. I use this Decal when I want to define details like the wall peeling off revealing the colour and texture underneath it or water leaking through the pipe and creating a stain.

Normal Decals: I use these decals when I want do define details only using the normal map. I generally use them for cases like when the wall is damaged or there are holes where only a normal map would do the trick. Of course, there are more ways decals can be used. There are different blending modes for cases when we need just a roughness map and who we want the opacity to be blended and so on.

Of course, there are more ways decals can be used. There are different blending modes for cases when we need just a roughness map and how we want the opacity to be blended and so on.

7. Colour Grading: This is a concept I use heavily from photography. Colour grading can elevate the mood and atmosphere of the scene even further. In my workflow, I use a LUT (Look up table) method. First, I download a neutral LUT defined by Unreal Engine. Next, I grab a screenshot of the scene from engine and import it to Adobe Lightroom. Lightroom is an application used by photographers for colour grading/processing the photos. There are different math functions used to for colour grading, namely, Lift/Gain/Gamma, Offset/Gain/Gamma and Shadows/Midtones/Highlights. I’m comfortable grading in the Shadows/Highlights space and Lightroom allows me to do so.

After I have finished colour grading, I copy the settings over to the neutral LUT I downloaded from the Unreal Engine documentation and export the modified LUT. This graded LUT is imported into engine and added into the post process volume, under the LUT settings.

Disadvantages of using LUT workflow:

• LUT works on an 8-bit image, that means this method will not work for HDR colour grading

• Not all the settings in the Adobe Lightroom or similar application will be carried over to the LUT. Only settings that change the saturation and luminance values of the image will be carried over

• The back and forth process across different applications may seem inconvenient for beginners trying the workflow

8. Particle Systems and Post Processing: Particle systems and post processing are the final stretch, the ‘cherry on the top’. This helps add some dynamic elements to the environment. For the above piece it was about adding subtle dust particles floating in the air, some procedurally generated smoke lingering in the air, bloom and exposure tweaks via the post process volume.

A Note on Camera Settings

We, as artists want to get the best screenshot of the environment/lighting work that we are doing. Apart from getting the composition and framing right, the settings one uses for the camera can have a significant impact on how the final images turn out.

I use Unreal’s Cine Camera Actor to frame and capture my shots. Cine Camera Actor provides a wide range of settings that reflect the functions of an actual camera – focal length, distance, aperture, aspect ratio, depth of field etc. It’s just like using an actual camera to take real world photos. With the right lens and right camera settings, we can capture amazing photographs!

General Tips About Lighting

• Lighting falls in this odd realm where either no one has any idea of how it works, or they shoot in the dark and hope lighting turns out the way they want it. I believe lighting is as technical as it is an artistic task. Without understanding how light behaves in the real world or how engines mimic this real-world phenomenon, lighting can end up being a more challenging task than it must be. PBR workflows, understanding the physics of light, learning the terminologies of lighting and understanding how a camera works in the real world are the fundamental knowledge one must understand first when stepping into the world of lighting.

• It is also important to make sure one doesn’t start with the process of lighting too late or too soon. Lighting is crucial in the entire development cycle. Lighting bleeds into so many workflows and becomes essential in a bigger picture. It helps with level design, environmental storytelling, setting the atmosphere and mood. A lot of design choices can impact the approach, a lighting artist will have to take for the project – dynamic vs static solutions, technical challenges, performance consideration etc.

• On the other side of the spectrum is jumping into a scene and zooming through the process of lighting. I take the approach of lighting up a scene in the order I mentioned above because I have more control and It’s easy to pinpoint where the problem might be. For example, Post processing or color grading needs to come in towards the end where we know we have final or almost-final scenario of the scene. It’s very tempting to start throwing in lights, particle effects etc early on because the scene isn’t looking good enough but the whole process takes time and patience. I would be lying if I said I never made the same mistakes early on when getting into lighting. 

• Lighting can be a very iterative process, and this can also involve the artists going back and forth and fixing materials and textures if the values are off. Sometimes the lighting will be thrown off because the base colour might be too dark or too bright etc.  

• I have always been a huge fan of movies generally. I think the film industry is way more matured than the game industry and there are a lot of inspiration, similarity we can draw from the film industry. Most of my references and inspirations come with movies. I watch and study colour, cinematography and lighting in some of my favourite films and analyse why it looks the way it does. It can be a huge learning experience to just mimic the colours and lighting of shot from one of your favourite films.

Outro

Whatever I have learned, it has been in the past 2-3 years. I’m thankful for my mentor Nora Shramek who helped grow through the process in the last year, and my teacher Ryan Brown for constantly giving valuable feedback. I have always believed in working towards something you are passionate about and making a career out of it. I know the game industry can be a difficult industry to break into but working hard, being humble and staying strong will always get us to where we need to be. 

Thanks to Experience Points for giving me an opportunity to write and share about my process. I would love to receive feedback and tips on both my environment and lighting work. Cheers!

Sourabh P Hamigi

Artstation: https://www.artstation.com/sourabhhamigi269

Website: https://www.sourabhhamigi.com/

Linkedin: https://www.linkedin.com/in/sourabh-hamigi-4354a411b/

Twitter: @sourabhhamigi