SFX: Turn It Up

Sound has the potential to greatly sell the feel of a game.

Once our artist’s priority tasks were completed, we began to add SFX once there was enough to work with.

So what do we add sound to? Before anything, we ran through the level slowly, and noted down any idea we had to where we could add sound.

This then gave us a basis to start researching and gathering sounds. We had limited time to complete the game, so there was no time for folly. We scoured the internet for royalty-free sounds. We would type keywords for both literally what the sound wanted was, and also what could emulate it.

e.g. Sounds for walking through bushes? Sure, you could search the term ‘bushes’ directly. But if struggling to find a satisfying clip, you could try something like ‘bag rustling’.

Not to mention, if several clips shared elements you liked, you could mix and merge them.

Unreal gives the option to mix sounds within the Editor. However we would that if we wanted more control on editing and timing, we would use the open-source Audacity.

Below are examples of how the clips would be utilized:

FOOTPRINTS

We felt that having the sound of the Detective’s footsteps change, based on what material he was walking on, would help enhance the feel of the environment.

Below is our Sound Cue template for achieving such an effect.

We have 5 types of materials that can affect them: Dirt, Wood, Water, Carpet and Stone.

To create variation amongst each sound set, we ensured we gather at least 5 different sound clips each. Each set would then be fed into a Random node, so that patterns didn’t emerge and distract players. Each Random node had a Mixer following it, in order to adjust the overall volume of each set, compared to the others.

Lastly we feed all these sets into a Switch node, which assigns an integer to each Sound Set.

These numbers are then called upon within the Detective’s Animation Graph. The engine knows which sound to play, because we send a Line Trace from the Detective to hit floor, querying what Physics Material is it hitting.

We would assign every surface to its relevant Physics Material in order to instruct the Engine, e.g. any rivers or puddles would have its area assigned the Water Physics Material.

Finally, how do we tell the Engine when exactly to play the Footstep sound? We do this by tagging our animations with a Notify (which we appropriately named Footstep). This essentially flags to Unreal when any action plugged into our Footstep notify should play.

Thus once this is all prepared, our Detective can get going with his fancy footwork!

Lastly this is an example of how we would add sound to animation events.

Here we have a Crane walking through the forest, knocking down trees. We gathered sounds for heavy-sounding metal clangs, and tree logs crashing into the ground. It was surprisingly harder than anticipated to find sounds to match the timing of the trees, so we ended up combing several clips, as seen in the bottom four tracks. The top two simply dictate the Crane’s footsteps.

It was important than when the player encounters this event, the sound would fade as the Crane would walk away. We discovered that the ability of Sound Attenuation wasn’t available in the Sequencer, at least with our current knowledge. Additionally we found that we could only animate Volume of sounds per clip, not as an overall track. This would make things complicated if we wanted to adjust overall sound levels.

So in order to create this effect, we would time the sound as seen below. Then record the sound with an external program to have it all contained in one clip.

Then we would mute all sound tracks in the Sequencer (not deleting them, in case we had to rerecord). Our new recording would be put into a Sound Cue, with the Sound Attenuation option ticked, and then be placed in the Editor, in the same position as the Crane walking.

To then have the sense that the sound is fading, we would add the Sound Cue into the Sequencer, and animate it travelling away from the player, matching the speed of the Crane.