SFX & Edit SFX

Sometimes, a GD level with a Newgrounds song just isn't enough to make your levels complete. You want to add in SFX to add details to your level. Imagine playing a Super Mario game, but without the iconic jump sound. It just doesn't hit the same. The new SFX trigger completely changes that now, and here's how to utilize it to your advantage. 

First place down the SFX trigger. When selected, click on the Edit Object button. The first page of the SFX Trigger is shown here.

Speaking of which, let's talk about the SFX options on the first page:

• As mentioned in the Song & Edit Song guide, the Speed slider changes the velocity of the song that is played in the channel.

• Pitch: Transposes the sound per semitone.

In music theory, there are 12 semitones in one octave, ranging from keys C to B.

In this piano chart to the right, we can move between semitones by playing the next note. Next semitone of C in this case would be C#, then D, then D#, and so on. If I were to play C, then move myself 12 semitones higher or lower, I will end up back to C, but a different frequency will be played.

Over on the bottom right, you can see 4 checkboxes:

• Reverb: Causes the sound to be repeated and bounced around numerous times in an echo. These could be used to insinuate a sense of space in an enclosed area in real life through sound. Tighter reverb details a small room (like a bathroom), while a big, open reverb details a big room (like a church). 

Clicking on the + Button on reverb presents you with a bunch of presets made for reverberation.

Note that there is a limitation to using reverbs. As of right now, there is only ONE global reverb channel. This means that you cannot use multiple sounds in different reverb settings played simultaneously.

• FFT: Stands for “Fast Fourier Transformation”. It calculates the DFT (Discrete Fourier Transform), or its inverse at a much faster rate. In music production, signal processing, and audio engineering, FFT is used to signal speeds and pitches in the form of frequencies in a given domain and also gives information about its signal. 

In audio engineering and software development, this is used for many applications, such as vocoding, multi-band compression, EQing, and simply for frequency analysis. Here is an example of using FFT to visually demonstrate a frequency spectrum of a song.

• If you would like to learn more about how FFT works, here is a link to a website that explains the general basics about Fast-Fourier Transform.

In Geometry Dash, we do not need to worry about how to apply all of the complicated post-processing effects to our sound. In this case, FFT is used as a different stretching algorithm for sorting speeds and pitches.

In comparison to FL Studio, this is equivalent to using resample vs stretch mode when stretching audio.

Let's head to the next page of the SFX Trigger by clicking on the right arrow. The second page has the following options:

• The Start slider allows you to start from any timestamp in the song, and vice versa for the End slider.

As before the values are in milliseconds, so 1 second is actually 1000 in value, 2 seconds = 2000, and so on.

• The FadeIn slider gives values of how much the song goes from no volume to its actual volume gain (Volume Slider), and vice versa for the FadeOut slider.

Let's head to the third page of the SFX Trigger by clicking on the right arrow.

On the left, there are two counters and a slider:

• Unique ID: A new ID dedicated to SFX. The sounds get linked into these Unique IDs instead of relying on Group IDs.

• SFXGroup: A new ID dedicated to sorting SFX IDs into groups.

• MinInterval: The minimal interval that occurs before playing the sound effect. Behaves like a cooldown. 

• Use UniqueID and SFXGroup to organize your sound library and to know which Unique ID and SFXGroup are correlated.

On the right you have 3 checkboxes:

• IsUnique: A constant Unique ID in the SFXGroup that makes it so that no other SFX are able to replace or substitute itself.

• Override: Unlike IsUnique, this gives the ability for SFX to be able to replace or substitute any Unique IDs and SFXGroup.

• Ignore Volume Test: Ignores volume being adjusted by proximity (i.e. If the proximity makes the Volume go to 0, enabling this will ignore it.).

Let's head to the final page of the SFX Trigger by clicking on the right arrow.

This entire page deals with proximity based on the player, camera, or object. As stated previously, proximity in music is adjusting volume gain based off of the distance relative to an object or player. The farther away the target is to the object, the less of an effect it'll create. The closer it is, the more effect it'll create. 

• Group ID 1 is the target object that will be used when calculating the proximity.

• Group ID 2 (when applying proximity with Group ID 1) is the object that will be applied to the object.

In the left set of sliders, you can adjust the volume for whatever distance you set it to:

• VolNear: Volume in a near distance. This creates a red area when selecting the SFX trigger.

• VolMed: Volume in a range of distances between Near and Far. This creates a green area when selecting the SFX trigger.

• VolFar: Volume in a far distance. This creates a blue area when selecting the SFX trigger.

In the right set of sliders, you can adjust the distance of VolNear, VolMed, and VolFar in their own respective sliders labeled MinDist, Dist2, and Dist3. Adjusting these sliders will also move the colored areas accordingly. 

Note that these colored lines represent a visualization of proximity. 

This video demonstrates uses of the SFX and Edit SFX triggers: