When making a video game, you can rely on certain techniques to guide the player. These include spotlighting specific items and pathways to direct their gaze. But what happens when your game doesn’t have a conventional lighting system? Or even an organic color palette?

The cave exploration game Scanner Sombre, developed by Introversion Software (the creators of Prison Architect), has the answers to these questions.

Waking up in a pitch-black cave, the player uses a LIDAR (Light Detection and Ranging) sensor to travel through the darkness. You might assume this would make navigation difficult, but Introversion have done more than enough to ensure that players stay on track, creating an experience that feels both accessible and deeply atmospheric. The team took advantage of environmental cues, item upgrades, and clever sound design to achieve this goal.

The eureka moment

Chris Delay, the lead designer on the game, originally came up with the idea of using LIDAR imagery for a new video game project after viewing James Frost’s music video for Radiohead’s "House of Cards" back in 2009. The video in question used LIDAR technology to detect the proximity of lead singer Thom Yorke’s face to a sensor, creating a 3D visualization that gave off a “moody atmosphere” and also felt “cold and inhuman,” according to Delay.



Radiohead's "House of Cards" video

“I just completely fell in love with that visual style,” he states. “I found tons more LIDAR imagery online after a few searches. I then developed a super quick prototype using simple raycasting against a building mesh."

“Fast forward a few years and we were deep into developing Prison Architect, and I decided to take a month out to develop some prototype ideas," he adds. "Scanner Sombre was one of the prototypes I developed. My main aim was to make something incredibly atmospheric -- to put the player in an environment that perhaps they'd never seen before.”



The game world is illuminated by LIDAR

The LIDAR tool as a guide

In place of lighting and a traditional color palette, the team depended on multiple techniques to feed information to the player. The LIDAR tool, for example, was used to communicate distances and shapes, giving players an impression of their surroundings in the darkness.

The sensor works by emitting a few thousand rays per second in the given direction. This illuminates the environment in different colors (red, green, and blue), with the color corresponding to an area’s distance from the device.

The player is dependent on the LIDAR tool to successfully move through the environment. It’s also necessary for uncovering contextual cues hidden throughout the game’s location and taking note of areas that you’ve previously explored.

Delay explains, “The levels are full of cues that are supposed to help guide you in the right direction.” He adds, “A simple example would be railings on the sides of staircases. We imagine they are placed there to stop people falling, and of course they are in real life. But in Scanner Sombre, those railings stand out from the background far more than the staircase itself does, and this helps the player realize where they need to go next.”

Upgrades as signposts

The developers also directed the player by offering incentives to travel to certain points on the map. For example, you can find upgrades for the LIDAR scanner throughout, which will allow you to shoot more substantial rays and locate your position on the map.

These items are used to reward the player for their curiosity and assures them that they’re heading in the right direction. It also offers some much needed variety to how they can interact with the environment through the abilities they inherit. These abilities make finding your way through the dark much easier.

“Without the feeling of progression on your primary interaction with the game, we found there just wasn't enough to sustain interest,” says Delay. “Getting upgrades to your scanner makes a pretty big difference to how you reveal the world as you play. And features like the map give you a whole new view on the world you are exploring.”

Creating atmosphere

Because of the game’s presentation and its obscure setting, Scanner Sombre is rich with atmosphere. It’s this feeling of isolation and wonder that causes players to have drastically different reactions to the environment and the individual situations that they find themselves in.

Introversion discovered that while some players enjoy exploring the caves thoroughly, others can’t help but feel afraid by their surroundings, and rush their way through.

“We were often amazed by how different the experiences were,” reveals Delay. “Some players love exploring such a strange place, others are so scared they can't progress beyond a certain point! Some people saw it as a place to be beaten, and others wanted to reveal as much of it as possible. I like the fact that many different people will have a different experience playing the game (and, of course, some people will hate it!).”

The sound design, in particular, helps to create this heavy atmosphere. Because the player is essentially blind, and the images of the world are reduced to the entirely artificial color palette of the scanner device, the team used sound extensively to convey location information.

These audio cues can be unsettling for some players, as it suggests movement in the cave not tied to the protagonist’s actions, with wood creaking and water splashing seemingly of its own accord.

Delay states, “Our audio guru Alistair spent a ton of time working on footsteps and reverb zones to fit the cavern sizes, and the thousands of wind sounds and water drips all over the place. If you close your eyes while playing the game and spin around on the spot, you can hear all the sounds of the cave moving around you. It's incredible!”