Field Report: High Octane Recording and Implementation of Engine Audio Karen Muro & Dave Lowmiller

Introduction Our involvement with Off Road Racing –Rainbow has made 8 off road titles over the last 10 years –The current franchise is MX vs ATV

Introduction Scope of MX vs ATV –Varied types of events All events require a separate mix with different goals –Off road bikes and Off road vehicles MX bikes 125cc, 250R, 250F, 450F Vehicles UTV, Off road Trucks

Introduction Why dirt bike engines behave badly? –Terrain –Driving Style

In other racing titles Motorcycle, Yes Terrain, No And that is what sets us apart

Design Goals Engines Create a realistic engine that mimics off road driving style while providing meaningful feedback to the player Implementation rules the recording and editing Build a system to trigger single samples based on the state of the bike

Design Goals Terrain and related sounds To capture the essence of off road, special attention needed to be paid to the terrains In addition to the standard drive on terrain loops, a system of one shot fairing hits was implemented per terrain type to bring the player into the environment

Recording Engines Off road bikes recording hot spots/ Mic Placement Dyno Logistics Recording Script Bike/Vehicle Procurement

Recording Terrains Drive On Loops recorded with the cart, helmet and mic –Lots and lots of dirt!! One shots for Terrain Generator- mimicking terrain hits on a fairing was done in the studio with a bucket of rocks and some bike parts We did use some library sounds for terrain loops where we couldn’t record

Editing Bikes Mix Them Mean –Each bike is different –Know your DSP limitations fully before mixing –Align compressions and rarefactions by hand if necessary –Don’t feel bad about dropping a track –A little modulation can be your friend –Master a brick

Editing Bikes (cont.) Cutting like a Moto Ninja –Cut to performance –Take advantage of implied throttle movements –Off throttle “negative space” is your friend –Use modular editing components –Mock up and audition

Editing Vehicle Engines –Standard Loop editing on the engines –4 Levels of RPM, On load and Off load samples

Implementation FMOD, why we chose it?? –We do not use FMOD to trigger our bike engines beyond setting up events that our state triggering system handles –We did use FMOD complex events for our vehicle engines, terrains & collisions

Implementation Engine States Each bike is roughly made up of 50 engine files and 17 different engine states At the most basic level is idle and all states return Powerbands instead of gears

Implementation Engine States (cont.) Most of states are driven from the physics, but the audio system is decoupled from the physics system in some areas A typical engine run might look like –Idle> Powerband1-> Powerband2->(Player going off of a jump) Every state is defined in an XML file

Implementation Why Crossfading does not work for us on bikes –Tried and implemented crossfading twice –Tried a Hybrid system= FAIL –Engine State triggering single samples= where we started

Implementation Terrain System –Drive on loops Pitched and increased in volume based on speed We used loops and one shots operating as loops

Implementation Terrain System (cont.) –Terrain Generator Driving/Riding –Random one shots set on a timer based on speed, these are also increased in volume with speed Skidding –Triggering factor is based on rear tire slip –Sample frequency is increased with heavy slippage

Mix Mix a brick of engines and a brick of music, what do you get? Oh and don’t forget the subtlety Defining Custom mixes per event type and racer quantity

Where do we go from here? The future of the badly behaved engine

Q&A