Microsoft Train Simulator 2 creates a realistic world for train enthusiasts, with accurately modeled terrain, cityscapes, suburban and rural settings, vehicle traffic, rail lines and yards, trains galore, of course—and people.

When your train pulls into a station on one of Train Simulator 2’s four high-accuracy routes, the platform is populated with lifelike people moving about, heading to and from the trains. You can also build your own routes in Train Simulator 2’s World of Rails that include stations, platforms, and character animations to enliven the scene.

In-cab characters in locomotives and train passengers in passenger cars also contribute to the vibrant, living world of Train Simulator 2, in which people and railroads interact as they do in life.

Character Variety

Creating a diverse crowd was our first challenge. We started with one male and one female body, and then added ethnic and age variations.

Two of the facial models

To this population we added hundreds of options for hair, clothing, and accessories. With all the different possible combinations of these factors, the result is a population of realistic characters that add life and variety to enhance your rail experience.

A group of women with a variety of clothing

High-Resolution In-Cab Characters

We’ve added specific characters for railway personnel, such as engineers and conductors, and modeled them in high-resolution detail.

A European train conductor. Click to enlarge.

High-resolution characters have significantly more facial details, because you will interact with them close-up in the cab.

An American fireman. Click to enlarge.

The Character Modeling Process

When we create a character, we start with a 3-D sculpture that uses as many polygons as needed (typically millions of polygons) to create a very realistic 3D model. Then, we create another version, using a much smaller number of polygons (a few thousand). The low-polygon version is used in the game, because drawing polygons on the screen is very “expensive” in terms of computing performance. But we don’t just throw away the high-polygon sculpture. We use it to create a “normal map,” which defines how light and shadow interact with the model. Combined with textures that define things like color and reflectivity, the normal map helps turn a relatively low polygon person into a very realistic 3-D representation.

An American fireman. The sculpture on the left is the low-polygon version, the sculpture in the middle is the high-polygon version, and the textured character is shown on the right.

The Science of Motion

Animating these characters so that they look, move, and behave as people really do was also a challenge. To reproduce the subtleties of human movement, we used motion capture, wiring live actors with sensors to capture the way they move in numerous situations. This is the same labor-intensive technique that allows CGI (computer graphics imagery) characters in films to move in natural and convincing ways. Constraining animated characters to the correct areas is also an important part of the process. By placing boundaries, we ensure that characters on platforms move realistically around obstacles and don’t simply wander out of the scene (or in front of trains!).

Population Density

Population density created more challenges. First we had to create sufficient crowd density to simulate real rail platform activity, and then we addressed the issue of how to populate platforms with these animated characters as efficiently as possible to maintain good simulation performance, including frame rate. To do this, we found ways to add depth and greater apparent density to crowds that are frankly less numerous than they might be on real-world platforms. This is achieved partly by combining moving and static characters, along with foreground and background characters.

On our platforms in Train Simulator 2 we mix people who are moving at various paces with people who are standing still. Some are strolling toward their trains, some are hurrying. Others stand and wait in various lifelike attitudes. Even these “idle-state” characters are not entirely idle, as they shift their positions and make occasional gestures to enhance the sense of a living crowd. To further increase the sense of a crowded platform, we may populate areas farther from the train with “impostors,” low-detail 2-D approximations of the varied people that make up the crowd, but who respond convincingly to realistic 3-D lighting to enhance their appearance. This mix of animation techniques recreates the bustling sense of density found on rail platforms.

This scene contains 3-D characters in the foreground, 2-D characters in the background, and a mix of 2-D and 3-D characters in the middle distance. Click the image to see a larger scene.

Summary

Our character animations in Train Simulator 2 enhance the simulation by populating trains and railway platforms with people who reflect the realism of the trains and scenery, creating a satisfying railroading experience and a living world.