Interview: Designing the audio for Planet Coaster

Planet Coaster is a theme-park construction simulator from Frontier Developments. While you might know the developer for the space trading adventure Elite: Dangerous, they also have quite a lot of experience in rollercoasters.

Frontier developed DLC for RollerCoaster Tycoon 2, all of RollerCoaster Tycoon 3 and Microsoft’s most recent Zoo Tycoon game. So they went in to creating their own IP, Planet Coaster with some great pedigree. But to create the feel of an authentic theme park, the audio team went back to the drawing board.

“During pre-production, the audio-team discussed their experiences of coaster parks and fairgrounds,” explains lead audio designer, Matthew Florianz. “We also worked closely with the other departments in understanding their goals and approaches.

Many members of the team were asked to ‘puke’
to get those sounds.
Matthew Florianz

“Lead artist Sam Denney is our resident ride expert and there’s nothing he doesn’t know about those contraptions. He was probably our fiercest fan and critic simultaneously, and it really drove the quality of audio to have someone like him talk to us from the start. 

“Eventually we came up with a ‘wants’ list – music, individual mechanical sounds, screams. The human element was especially important to us – the presence of ‘life’ in the park. Our park guests power every aspect of the simulation, so making them feel real was very important.”

Once the team had decided what sounds they needed to hear, the first job was to capture the audio they needed. “For Planet Coaster we chose to start from a clean slate,” explains Florianz. “Lead sound designer Michael Maidment brought a lot of his experience from working on Screamride to the game.

“For source material, Michael and I went to a local fairground to record the rattling rides. We also recorded rides at different distances to get an understanding of how sound propagates. 

“Michael also built a ‘Rolling Road’ in his room, using his own upturned bicycle. Finally we worked with US-based sound recordist, Watson Wu, and closed a theme park for two days to arrange recordings. We wanted to use very clean recordings of coasters and record screams separately. His pristine recordings of coasters, rides and log-flumes formed the basis for equivalent rides in game. 

“When it came to designing the first coaster, I used one of Watson’s recordings and tried to deconstruct elements into separate layers. Then I ‘re-created’ the coaster audio and tried to score it with the layers, to figure out techniques for real-time implementation, as pictured below.

“One of the interesting finds of prototyping to video was that pitching didn’t sound authentic. Instead we apply band-pass filtering. We take certain frequencies and enhance them in real-time, sliding up and down from treble to bass to follow exact track or coaster physics changes. It’s a lot of layers but we felt that we needed all the variety and layering to make them really reactive to all the extreme tracks users can build.

Players are mixing the audio themselves. We provide a
robust framework that allows anything to happen.
Jim Croft

MIXING IT UP

Planet Coaster, unlike Elite: Dangerous, didn’t appear as an Early Access title. Instead, the game was iterated internally through alpha testing and then publically through beta. So being able to create a system that mixes the audio authentically and dynamically must be a difficult challenge. "There are some key goals to everything we do here in the audio department at Frontier," says head of audio, Jim Croft.

"With every game we strive to reach and hopefully surpass those goals by asking ourselves: Does the audio reinforce the visual in a satisfying and informative way? Does the audio give corresponding, informative and satisfying feedback based on player input? Does the audio have enough variety and is the soundscape always changing to combat listening fatigue? Are we achieving all of the above in a scalable and efficient way?

"With a game like Planet Coaster, where we are looking to achieve really ambitious levels of realism, detail and scalability, we have had to create systems that allow the player to dictate the mix. Players can really do anything they like, so we have had to create systems behind the scenes that cater for that by setting the technical boundaries and dictating a robust mix rule set.

"Players are mixing the audio themselves. We provide a robust framework that allows anything to happen (even if nothing is happening) without it becoming either cacophony or boring or breaking down due to technical limitations."

With the way the audio is staggered, some things need to be more prominant than others, and Frontier developed a theatrical approach to the potential cacophany of sound. "Jim often likes to stress natural dynamics and how a design needs to respect it," says Florianz. "I’m often coming in from the opposite direction, wanting everything to be highly reactive. When we talk about music for instance, highly-interactive music could risk becoming a ‘cartoon’ score (where music precisely follows the actions on screen, but fails to convey more as a result) just like a highly dynamic piece of music could fail to respond to the choices that an experience offers.

"We always find a great middle ground and for Planet Coaster that resulted in a further set of guidelines. The soundscape (music, audio) had to be informed by the park build (in support of user’s creativity). It had to be dynamic, adaptive and interactive. It also had to be diegetic unless a situation arises where the first two rules cannot be applied, and any implementation we did in code or in Wwise needed to be able to scale.

"The first rule is rather technical. We knew we wanted sounds on everything and that approach can get expensive quickly, especially in a game where the environment constantly grows in complexity. we treat the game world like a stage that has a background and a foreground. The actors (the important parts) are in the foreground and our systems seek them out specifically. We only need a few of those foreground actors to produce the more expensive detailed and synced sounds.

"The background doesn’t need the same level of detail nor perfect sync. So for that layer (the majority of sounds) we derive context from data rather than actual objects – for example, we will see what the particular ‘mood’ in a section of the park is and adjust the audio accordingly. In combining a foreground and background layer, we can support a fast moving camera (as we can swap out actors dynamically and only need to do so for a few) and represent exactly what a user has built. It is the park itself, which provides the pulse to the dynamic soundscape.

"There are moments when the park is not able to sound dynamic. Users could be building far away from where rides are, or have chosen to pause time progression in the game. When that happens our music system will flag that the soundscape is becoming un-dynamic and will introduce non-diegetic music. The system was designed and implemented by Technical Sound Designer Stephen Hollis who did an absolutely fantastic job both technically and creatively. His code will certainly be used on future projects.

PLANCO-ESE

"Are you mad?" That’s what I said to Frontier’s senior audio designer, James Stant. That’s because he’s invented a language for Planet Coaster – Planco. Inventing a sensible language is something that video games rarely do, because it is difficult and can be incredibly irritating. "Maybe we are a little crazy," admits Stant. "But it was very much a labour of love and Planco epitomises the lofty ambitions that we share as a development team.

"We strive to achieve innovation and push far beyond what is expected of us. We set out to create a language that was identifiably human yet at the same time rooted firmly in the Planet Coaster Universe. Planco is a unique language for the unique art style that artists John Laws and Matthew Preece had envisaged.

"Accessibility was always regarded as an important pillar and as such we chose to use the familiarity of English alphabet and grammatical structure; translation to/from Planco was then as a simple as one-for-one word replacement, providing our voiceover talent with an instinctive sense of pacing and emphasis.

Then we just had the small matter of building a glossary containing thousands of words and doing so within the game’s development cycle. However if you can find a workflow that genuinely inspires and excites you – as I did with my creation methods of word association, onomatopoeia and emulation – then the process remains manageable and the product retains a sense of familiarity. 

THROWING UP 

Yes, with the creation of audio for human beings in a theme park, one sound – one wretching sound – must also be recorded. "Many members of the team were asked to ‘puke’ to get those sounds," says Florianz. "We have a lot of talent at Frontier and we often end up falling in love with temp tracks/voiceover so what you hear in those situations is often members from the Elite Dangerous and Planet Coaster team giving it their best and all. We were always very careful not to make it to explicit as we felt the moment is one of comedy and information rather than wanting people to actually feel sick."