Immersion Challenges: Simulated Bike Engine Vibrations for ‘The Jump’

I wanted to talk about how I originally solved the bike’s engine vibration simulation for the experience and then discuss how looking back I would have solved it in a much cleaner and simpler fashion.

As you saw above, I had a 5.1 file for the LFE channel that controlled the bike engine vibration simulation with a Buttkicker. As you can see how I implemented the files in this post, by having events with a ton of 5.1 audio files, it uses up a lot of disk space and is not ideal. Luckily, I didn’t have to worry about it because I had a beefy pc all to myself.

To generate some infrasound frequencies I used Adobe Audition’s frequency generator where I could create singular tones or sweep between two of them.

After some brief experimentation, I settled on using a sawtooth wave form as it simulated the linear movement of the pistons making the vibrations feel more authentic. When the bike was running at full speed I let it plateau at 44hz because above that the vibrations became less detectable on the bike and I never went below 13hz for impacts as that was the minimum frequency response of the Buttkicker.

The downside of using these audio clips other than disk space is clipping where the file’s last sample be right at zero amplitude or the amplitude had to match perfectly at transitions or fade the clip out before the clipping occurs. These problems lead me to reconsider how I might solve it differently.