Brad's Sonic Musings

Tag: skateboarding

  • Psuedo-Occlusion in Unity

    Unity is an awesome engine for quickly iterating and building game content. The audio features have definitely improved over the years, but it’s still rather limited in many ways.  Randomization of pitch, volume, lpf, or even sounds can only be done with a little bit of scripting savvy.  Someday, either Unity will fix this or I’ll publish my scripts for these common practices on the asset store :-).   One of the features we added at Free Game Games which I’m most proud of was a psuedo-occlusion scheme utilizing trigger boxes and an enum (and enumerated static variable) to attenuate and apply a low pass filter on certain sounds. This feature was used prominently throughout Free Range Games’ canceled skateboarding game, as well as Freefall Tournament, which is playable on Kongregate.com.  It was one of the more advanced features we added to Unity on the audio side.  I relied heavily on the scripting wizardry of Jeff Wood, a fantastic designer whom I worked with both at Free Range Games and Shaba Games before that, to handle most of the technical scripting. Our solution was not necessarily the best method to occlude sounds, but it was functional, so I’d like to outline the system so that people can ideally glean some information from it and possibly improve upon it themselves.

    The core script components of our system were an AudioOcclusionTrigger and an AudioOcclusionObject.  All objects the we wanted to occlude would have an AudioOcclusionObject script attached to it.  To trigger the occlusion we created trigger boxes and attached an AudioOcclusionTrigger to that trigger box.  Since we may want an object to be occluded in multiple boxes, we created an enum containing a list of occlusion “categories.”  This list was rather arbitrary and dependent on the level design.  I believe we had things like “Hallway,” “ExtAmbience”,  and “IntAmbience” So for example in our skateboarding game, we had a warehouse level in which two cavernous rooms were connected by a small hallway. Each room had an ambient emitter which played a looping ambient drone and  occasional one shots and a PA loudspeaker which was pumping out our licensed music soundtrack. The hallway had a trigger box around it with an AudioOcclusionTrigger script labeled as “hallway.” The ambience and music emitters in each large room where tagged with the hallway enum with their respective AudioOcclusionObject scripts, and whenever the player entered that trigger, all the sounds which contained an AudioOcclusionObject script with the category set to “hallway” would  attenuate and get filtered over time.  And when the player exited that box, the reverse wold happen (the objects volume and lpf would be restored to where they were prior to occlusion).

    Here is a short video demonstrating the effect on the music and ambience:

    We did a lot of safety checks to make sure the sounds aren’t already occluded before attempting attenuation, creating filters if they don’t exist, etc. but it’s still a far from perfect solution.  It really only works well with fairly simple geometry and the more occlusion categories you add, the crazier it can get to keep track of your objects and make sure everything is set up properly.

    But there you go.  If you’d like to download the scripts and check it out yourself, they’re available here.

  • Adventures in the Field, Volume 1: Skateboarding

    Undoubtedly, one of the most enjoyable, fun aspects of being a sound designer is field and foley recording.

    Perhaps one of the fondest memories of my career was when I was working for Konami in Hawaii.  We were doing a PS2 game called Ys VI: The Ark of Naphishtim in which there was a cutscene with a huge pirate ship battle.  There were a lot of cannonball blasts and splashes, so to get some good cannonball impact sounds, myself and the other sound designers, Jaren Tolman and Stillwind Borenstein headed over to the leeward side of the island where I proceeded to jump off a concrete pillar into the middle of the Pacific Ocean while Jaren held the Rycote blimp on a boom extended out over me and Stillwind ran the session on his laptop.  We couldn’t believe we were getting paid to do this!

    More recently I was working on a skateboarding game.  Unfortunately, due to circumstances far beyond our control, it never saw the light of day. However it was another fun project that afforded me the opportunity to experiment with and record a variety of sounds in a realistic fashion that ended up sounding great in the game.

    When we were first approached with the project, I instantly started thinking about how to get some good skateboarding sounds.  Do I hire a pro and follow him around with a boom and a blimp? Is there a way I could somehow record all the necessary sounds myself? Being that this was a start-up, we had no budget for hiring anyone, nor did I have such necessary equipment at that time like a blimp or even a decent field recorder.  So I opted to try some experiments with a DIY rig to see if I could make some quality sounds on the cheap. For recorders I had an Edirol R-09 and a Zoom H2. I opted for the Zoom because, while the preamps aren’t as good as the Edirol, it was also one-fourth the price, so if it got destroyed, which seemed likely, I wouldn’t be as pissed. To capture the sounds, I wanted to affix the recorder to the board, but needed a method that wouldn’t cause noise. I started with a piece of foam I found, that I believe came from a hard drive package. I cut out a hole to wedge the recorder into and duct taped it to the board.  Ghettotastic!

    And the results turned out really well!  While I can’t show off the game for legal reasons, here’s what the audio content, all recorded in this method, sounded like:

    Now, I’m no pro skater, so the only times I was actually riding the skateboard was to capture all the rolling sounds and a few of the ollies and landings.  Most of the ollies, landings, power slides, bails, etc., were all recorded with the recorder firmly tucked into the foam and me “simulating” the movements as if it were a giant finger board.  I would apply ample pressure so it sounded like there was some mass on the board and eq things when designing the actual sounds.  But every skateboarding sound you hear was captured with the skateboard above and that magic piece of foam.