Making a Train Car: Lighting, Decals, Materials, Scale

Hugh Trombley did a very nice overview of his ‘Train Car‘ environment, which was inspired by Clinton Crumpler’s work.

Intro

Hello my name is Hugh Trombley I’m 23 years old from Los Angeles, California and I’m a 3D Environment artist. After graduated from college, I worked freelance for a short time before I got to work at Infinity Ward on Call of Duty: Infinite Warfare. After that I relocated to the Bay Area to briefly work at Sledgehammer Games, for Call of Duty: WW2. Currently I work as a 3D Artist for the Interior Design company, Houzz.

For a long time I’ve wanted to recreate something I see throughout my day when I go to and from work. After seeing the work of Clinton Crumpler and his Train car project I became inspired to work on my own local train transit. My main goals were to recreate the look and feel of the train from the image and to better practice my light which I felt wasn’t one of my strongest areas.

Blockout

First I needed to block out the general size and dimensions of the train, from there I had to block out using primitive shape static meshes. Doing this helped with creating size templates from when I went to refine and fully flesh out assets, such as my seats, which were the primary assets in a train car. They were originally placed with the right spacing and the right dimensions, then once my new seat was created, I could then select my blocked out mesh and batch replace my new seats to save time. Once the seats were placed in the scene I could start working around, refining the lighting, smaller asset placement and finally the modular pieces for the train itself.

Scaling

First I made a template Maya scene using the Imperial scale, then I imported in the default UE4 Mannequin as a human reference scaled to 6 feet which is my height for when I do relative dimensions. Next, I went on the train and began measuring things, such as the width of the individual seats, seat frame width, and the doorway dimensions, etc. Then using profile photos front the side and my dimensions of the door sizes, I could accurately make a block size of the train car. My major problem was creating modular pieces to build the train out. In the end, I tested to make sure I could snap the pieces together in Maya before I import them into Unreal for the final assembly, which was made easier using the same method from before of batch replacing the objects.

Materials

When you recreate something that so many people ride on a day to day basis, you have to pay attention to detail because you’ll have so many people that point out what’s wrong if you miss your mark. So when I went on the Bart I took some close up images of the surface detail as well as some Color-Corrected images of the seat materials, the walls, the floor and the metal. From there I could create a good base material in Substance Designer using accurate colors for the Albedo and reference for the normal and roughness maps. Since I’ve ridden the BART for a few months now and I don’t think I’ve ever paid attention to small details like the fabric of the seats. But once I started to recreate them, a few of my colleagues pointed out how the seats look weird, mostly because the colors were off, or the surface was too smooth, or the fact that seats looked “too new” and weren’t “dirty” enough. It’s apart of the “Uncanny Valley”, people remember the look of things subconsciously and if something looks too real and unnatural, it causes the brain to become uncomfortable upon viewing. To get around that I had to recreate the materials in my scene, namely the seats. I took the base materials of the fabric in Substance Painter and created a more “used” base and also a more dirty version to Vertex paint to add variation to each seat. I also did the same with the floor as well. One of the best choices I made was using tiling materials instead of fitted texture sets for the train car pieces and some of the other assets. It makes it easier to re-use textures to make different materials more quickly.

2d Elements

When it came to the decals of the scene, mainly all the signage and the stickers for “Priority Seating” and “Bike and Wheelchair Areas” I tried to find them on online. I was able to find somethings, like BART ad placement and the Train Map. But everything else I had to actually take the photos on my phone while I rode the train.

What I would do was take the photo with little to no shadow or highlight as possible. Then I would take the photo into an app called, Microsoft Lens. It’s a app that can realign and crop a photo or document to be flat like a photoscan. After that for all the decals I had I took them into Substance Designer to create an Atlas sheet for all them to use. Then I would take that atlas in Unreal Engine and using a technique with The UV Texture Coordinate Node. I can offset and scale to each of the decals. Using only one texture and saving time with without needing to compile the texture every time. The same can be said about the the graffiti decals. The signage was done the same way, pictures were taken with as little to no lighting and then, cropped and aligned and then brought in individually for each sign. Adding to the authenticity was adding small graffiti, scratches and dirt to the signs to make them look more believable.

Lighting

Lighting has always been a tough subject for me, so I wanted to take the time to get better at it. For starters, when I posted my first work in progress image, I started with spotlights, because I felt the way the lights were shaped had a bit of falloff like the way spotlights do. But I tried not to work on lighting until I started to get materials in the scene. Once I got the seats in which were my main focus assets, I finally took sometime to tweak the lighting. But every time I decided to change something drastic, I would make screenshot of my previous settings to revert to if I didn’t like the result. Next I adjusted the Lightmass to take in more bounce light to help brighten up the scene.

I created a blueprint using the spotlight with a bit of geo, a point light and an emissive material to make the template for the panel lights on the ceiling. Then using some point lights I made into a long bar shape I used those to create the highlight on the top of the seats. The rest of the lighting was a mix of reflection captures, screen space reflections and post processing. The biggest challenge was pushing how much lighting to do with actual lights and the rest with Post Processing. What I did was take my light as much as possible and use as minimal post as possible to achieve the optimal look from there.

The Challenges 

Overall some of my biggest challenges for the scene was to make it have that unique BART look, to give it that history that showed that people had actually taken the train and that it was actually used.  What I loved was when I would make a progress post and people would comment on how the lighting and color looking just like when they were on the BART the night before or when people said they could practically “smell” the BART which was nice. The comment I mean, not the smell, the BART  smells pretty bad on certain days. Also what was great was how much easier it was to reuse tileable materials on meshes with custom normals and how you can take textures from one material and reuse them to make a completely different material without having to go back into another program. Some advice I would say is don’t try to push your asset creation so quickly, take the time to really research and if you get the chance to actually see the reference in front of you, take the chance to record how the light affects it or what the close up surface looks like or even how tall it really is. We get so excited to start bringing in assets without really taking the time to make sure our scales are correct, or how we can take the steps in the early part of production to make it easier to iterate and take what we have in our block out and make them the basis of our actual assets. Also take the time to admire to small things, every scratch, mark and stain add history and character to what we see.

Hugh Trombley, Environment Artist.

Interview conducted by Kirill Tokarev.