Tutorials · Sound and Music · Chapter 8

The bell

A bell to ring

1. In Assets, click bell.wav in audio, set its Stream to Never in Details, and press Save. At six seconds Auto would stream it; a sound struck on a key is held whole, so each strike starts at once.
2. Select bell, in bell_chamber. Press Add component and choose AreaComponent. In its Shape, set Size to 48, 48: the floor round the bell. Leave its Layer and Mask as they come.
3. Press Add component and choose AudioSourceComponent. Leave Clip empty, Bus on Sfx, Volume at 1, Positional ticked, Max Distance at 512 and Rolloff on Quadratic, as they come. Set Min Distance to 48 and Max Voices to 1.
4. Add a trigger toll, its Clip bell.wav.
5. In Assets, click Assets in the path bar, so the script is written at the project’s top, then click Create, choose New script, type bell and press Enter. In the Code tab, replace everything in bell.rgs with the script below, and press Ctrl+S.
6. Select bell, press Add component and choose Bell. Press Ctrl+S.

/// The bell in its chamber. The knight rings it standing by it, as often as
/// he likes: each toll rings on for several seconds, and the music dips under
/// it while the ring is loud.
component Bell : Area {
    /// How many knights stand by it.
    #[readonly]
    near: i32 = 0,

    fn on_enter(other: NodeId) {
        if in_group(other, "knight") {
            near += 1;
        }
    }

    fn on_exit(other: NodeId) {
        if in_group(other, "knight") {
            near -= 1;
        }
    }

    fn loop() {
        // E, which the input map calls action, pressed while he stands by it.
        if near > 0 && pressed("action") {
            play_sound("toll");
        }
    }
}

The music dips under it

1. Select mix. Press + beside Ducking: a row, 1, reading Sfx>Music as a row comes, its Trigger Sfx and its Target Music. Open it.
2. Set Threshold to -18.4, Amount to 9, and Release to 1. Leave Attack at 0.05.
3. Press Ctrl+S.

The Audio Mix’s Ducking

Rules that hold one bus down while another is loud, a row each. The Inspector reads each by its place and its two buses, 1 and Sfx>Music, the bus that listens first.

A duck’s Trigger

The bus it listens to: here Sfx, the whole bus, after its chain. It hears the bus, not the bell: anything on Sfx loud enough would duck the music too. Not Master, the sum of everything it would duck: a row whose Trigger is Master is dropped, and the Problems tab says so.

A duck’s Target

The bus it holds down: here Music. A bus cannot be both: a row whose Target is its Trigger is dropped, and the Problems tab says so, as below.

A duck’s Threshold

How loud the Trigger must be for the duck to come on, in decibels under full scale, from -96 to 0. The bell’s ring reads over -18.4 on the Sfx meter for its first three seconds and more; nothing else in the crypt reaches it.

A duck’s Amount

How many decibels come off the Target while the Trigger is over its Threshold: 9, which leaves the music at a little over a third of its level. From 0 to 96.

A duck’s Attack

How quickly the duck comes on once the Trigger goes over, in seconds. It is a time constant, not a ramp: at 0.05, the duck is most of the way on in a twentieth of a second and all but fully on in about a fifth.

A duck’s Release

How quickly it lets go once the Trigger falls back under, in seconds, a time constant too: at 1, the music is most of the way back in a second and all but back in about four, so it rises with the ring as it dies rather than jumping back.

Everything else, under it

The music in the cave

1. Select mix. Press + beside Sends: a row, 1. Open it, and set From to Music and To to Sfx. Leave its Amount at 0.
2. Open the snapshot cave, and press + beside its Send Amounts: an amount for the row, reading Music>Sfx, at the row’s own 0. Set it to 0.5.
3. In passage and in well, press + beside Send Amounts and leave each at 0.
4. Press Ctrl+S.

The Audio Mix’s Sends

Rows that feed some of one bus into another, a row each. A sent copy is heard where it ends, on Master, and not on the bus it is fed through: the Sfx meter, which the duck listens to, never hears the music, so the music cannot duck itself.

A send’s From

The bus that is tapped, after its own chain and fader: here Music.

A send’s To

The bus whose chain the copy is fed through, and then its volume: here Sfx, for its Reverb. So the music’s ring in the cave follows the options’ Sfx slider as well as the Music one.

A send’s Amount

How much of the bus is sent, from 0 to 1: the row’s own, used wherever a snapshot says nothing. Here 0: no snapshot but the cave’s sends anything.

A snapshot’s Send Amounts

How much each of the mix’s Sends carries in this snapshot, an amount for each row by its place, read with the row’s two buses, Music>Sfx. A list shorter than the Sends leaves the rest at their own Amount. The cave’s 0.5; the passage’s and the well’s 0, the row’s own, written out so the Inspector shows them.

Who decides what you hear

The bell and the send

Check it works