Creating a Sedan-Like 3D Car Using Unreal Engine 5

Introduction

Hi, my name is Filipp Sparak, I am from Saint-Petersburg, Russia. I've been doing 3D for the past ten years and have been in the gaming industry for the last five years. I first started learning to model in college and have kept expanding my skills and picking up adjacent ones at every new job.

I worked on Saints Row 2022 and Bloodlines 2 as a Level and Environment Artist respectively. Both these projects were somewhat influential in my decision to create my own city environment (The Projects), and as a result, I needed some vehicles to fill the streets. The Sedan was one of them.

Design & Reference

From the start, I decided to find a middle ground where the design wouldn't be too complex, but also not simple, so that it could blend nicely into the environment I was making and still be good enough as a personal piece of its own. It also had to contrast size with the already finished small Hatchback and enormous Tanker Truck.

As a result, I settled for a large sedan-type car with various generations of Cadillac Fleetwood as the main inspiration. That's how this sketch, drawn in Procreate, came to be.

I used a PureRef sheet that I made earlier for the hatchback to cover most grounds for the suspension, chassis, engine bay, frame, individual interior elements, door hinges, etc. Then I put the sketch I made and a handful of Fleetwood photos on the side as well, and just started modeling from there.

Modeling

The first thing I had to do was to get scale references, so I put a 180cm biped in the Max scene. As the car body blockout started getting fleshed out, I also put a couple more bipeds in what would be the interior as a guide to create correct proportions, logical ergonomics, and then proper cuts to what would be doors. I then took a bunch of engine bay and suspension elements that I modeled earlier for the hatchback, repositioned and tweaked some of them to fit the new body. This also helped blockout the frame and chassis around it, where all the parts could be connected correctly in a spoke manner without any jank. These steps probably saved me over a week of work.

Beveling

As this car was a part of The Projects environment, it would naturally follow a similar modeling and texturing pipeline that I used on the other props and modules.

First, I finished the entire car with all of its geometric parts, but kept the edges sharp and low poly. The next step was to add fake bevels to the edges of every single mesh save for the smallest bolts and spacers. To keep this part consistent, I used a range of .4 to 1.0 values for the bevels' width on most objects, .2 to .3 for small ones, and I would do 1.0 to 4.0 for the thickest bevels. Anything above these on a convex edge would receive a real bevel during the previous stage of modeling to avoid the issue where the silhouette obviously doesn't match the normals direction.

The reason I like this technique is that it's easy to apply. You can adjust the width of the bevel by moving control edges at any time, and it doesn't require a lot of extra geometry. There is no need for weighted normals, it keeps the original shape of the model, which allows you to cleanly backtrack and redo it if need be, and all that eventually saves a lot of time while not being a huge visual compromise.

Unwrapping & UV Channels

After the high poly stage was done, I created a rig. Then I color-coded and organized mesh instances into a separate layer and hid them. I removed all symmetry modifiers and sorted the remaining geometry into UDIMs, which would be auto UVed one by one and moved to the second UV channel to later be utilized for RGB masks. The first UV channel is reserved for the base tile. For this channel, I used box mapping with the same texel density as the rest of The Projects environment.

Texturing

With the UVs finished, I got the car back to the assembled state and started exporting the parts to Unreal Engine. I also sent the exploded version of the entire car to Substance 3D Painter to create UDIM RGB masks that would provide edge wear, dirt, and slight color variation to the surfaces and a mud mask utilizing the Alpha channel of the RGB mask. Another version of the car was sent to a different Substance 3D Painter file to create a livery mask utilizing the same UDIM UV channel.

Materials

Materials were assembled in Unreal Engine. They provide a range of customization parameters that allow for changing colors, properties, intensity of each RGB mask channel, livery colors, dust projection, etc.

Variations

Along with the extra parts that serve as add-ons to the car, you can make a bunch of variations with different looks, poses, and even silhouettes all inside Unreal. I needed this to break up as much repetition as possible while still only having three vehicle designs for the entire city.

Conclusion

As this car was supposed to serve as a prop in The Projects, I couldn't afford to spend too much time on it. I had to follow a simpler texturing approach and skipped the low poly stage, repurposed the suspension and engine bay from the hatchback, and finished the car within a month while working on it for about four hours a day after work.

This car, along with the two other vehicles, allowed me to learn a lot about the inner workings of an automobile, texturing complex objects, and vehicle design, and also helped me establish a streamlined approach for future similar pieces. The time constraint helped a lot with not feeling the need to do a perfect job, but rather raising the bottom line a little bit higher with every completed model, thus increasing the overall output while still producing quality work.

As a final note: it's important not to underestimate the role of presentation. Good and consistent presentation greatly increases exposure and makes your portfolio look more competitive. Research how the most followed artists in your field present their work, grab some inspiration from professional photographers, find your style, and build on it.

Thank you for reading. I hope you found a thing or two in this article that will help you tackle something you were not sure about before and raise that bar just a little higher!

Filipp Sparak, 3D Artist