Tutorials · Animation and Cutscenes · Chapter 4

Frame events

Footsteps you hear

1. Copy the footsteps, the thud and the knife below into the project’s audio folder.
2. Select knight, click Add component and choose AudioSourceComponent. Leave Clip empty, Bus on Sfx and Autoplay unticked: this source plays nothing on its own.
3. Press the + at the right of Triggers three times. Three rows, [0], [1] and [2], appear, folded. Open [0]: set Name to step, and the row reads 1 step, its place and its name. Drag footstep_wood_000.ogg onto its Clip.
4. In 1 step, press the + beside Clips four times, open each of the four rows, and drag footstep_wood_001.ogg to footstep_wood_004.ogg onto their Clip. Leave each Weight at 1.
5. Set 1 step’s Mode to RandomNoRepeat, Pitch Min to 0.9 and Max to 1.1, and Volume Min to 0.8. Volume Max stays 1.
6. Open [1]: Name swish, Clip knifeSlice.ogg; it reads 2 swish. Open [2]: Name thud, Clip impactSoft_heavy_000.ogg; it reads 3 thud.

Triggers

The Audio Source’s list of names it answers. Each row holds a Name, which a clip’s event track spells the same way, and the sound that name plays. A name no row has makes no sound.

Name and Clip

A trigger’s Name is the name the event track raises, step. Its Clip is the sound it plays. With Clips empty, it plays that one every time.

Clips and Weight

More recordings of the same sound, played instead of the Clip alone, so that a footstep is not the same take over and over. Each row has its own Clip and a Weight: how often it comes up against the others under Random and RandomNoRepeat, 1 for all of them here. Shuffle and Sequential pass over it, and in every Mode 0 mutes a take. step has five takes in all, the Clip and the four rows.

Mode

The order the takes are drawn in. Random picks any, by weight. Shuffle, which a new trigger has, goes through all the takes in a random order before it repeats one. Sequential goes down the list. RandomNoRepeat picks at random, by weight, but never the take it just played, which is what a footstep wants.

Pitch and Volume

A range each, Min to Max, from which every play draws its own multiplier: 0.9 to 1.1 shifts the pitch a tenth either way, and 0.8 to 1 takes up to a fifth off the volume. A new trigger has 1 to 1, which is no change. A little spread is what stops five takes sounding like one.

Bus

The mix the source plays through: Master, Music or Sfx. Sounds of the show’s own, like these, go on Sfx, which is what a new Audio Source has.

Trigger tracks

1. In the Animation tab, in the Frames mode, click the run tab. Under Frames, below the frame’s details, type step into Track name, choose Trigger and press Add track. A row step appears, with a cell for each of the twelve frames.
2. Click the first cell and the seventh. They light: frames 0 and 6. Each cell is a frame, counted from 0.
3. Click the land tab. Add a Trigger track thud and click its one cell.
4. Click the slash tab. Add a Trigger track swish, and click its third cell: frame 2, where the blade sweeps.

Trigger

A kind of event track: an edge, fired once. When the clip arrives on a marked frame, the track’s name is raised for that step, and the node’s Audio Source, and in later chapters its scripts, hear it. A cell is a frame, and only the frames you light fire. The first frame of a clip fires on the first step after the clip starts.

Active

The other kind: a state, held across a span of frames. It is on for as long as the clip’s frame is inside the lit run, and off outside it. It is for something that is live for a while, as the next section’s blade is.

Track name and Add track

The name a track raises, and which kind it is. The name is what a Trigger binding, an Area’s Track or a script spells the same way; one clip cannot have two tracks of one name. A bin on the row removes the track, and the three small switches before it, S, M and L, solo, mute and lock it, for a clip with many.

A slash that hits

1. In the slash clip, add an Active track called hitbox. Drag across its third and fourth cells, frames 2 and 3: the two frames where the blade is out. The cells light as one span.
2. Press Save in the Animation tab.
3. Select knight, click + Add node and choose Area. Rename the node blade.
4. In its Area, set Shape Size to 96 and 24, Offset to 0 and -22, and Track to hitbox. Leave Solid unticked.
5. Type blade into the Groups box and press +, so the node is in a group of that name. Press Ctrl+S.

The Area’s Track

The name of an event track on the clip the knight is playing. While that track covers the clip’s frame, the Area is live, and notices what overlaps it; on every other frame the Area is as if it were not there. Empty, an Area is live all the time, which is what a pickup wants.

The Area’s Shape: Size and Offset

The box the Area covers: its Size in world units, and its Offset from the node’s place, which is the knight’s feet. A Size of 96 by 24 is as wide as a slash frame, and not much taller than a sword, and an Offset of -22 lifts it so that it sits across his chest. Solid stays unticked: an Area notices, it never blocks.

A number on a frame

1. In the hurt clip, add a Trigger track recoil and click its second cell: frame 1.
2. Click the second frame in the strip of frames at the top, to put the playhead on it. A band, Values on frame 1, opens over the tracks, with a row for recoil and an Add value button.
3. Press Add value, choose Float, and set it to 220.
4. Press Save in the Animation tab, and Ctrl+S.

Values on frame and Add value

The band that opens when the playhead is on a frame a track covers. Its row for a track is where that frame’s payload is set: a Text, an Int, a Float or a Bool. The engine reads none of them for you: what 220 means is what the script that hears recoil makes of it. A dot in the cell says the frame has one, and the bin clears it.

Seeing the slash

1. Press F5. Select knight, and set the Animated Sprite’s Clip to slash. He slashes, once. The knife is heard on the third frame.
2. Click Render on the toolbar and tick Debug draw. Set Speed to 0.25, Clip to idle, then to slash again. A box is drawn across his chest for two frames, the blade’s, and is gone. Set Speed back to 1.
3. Set Clip to hurt. Nothing is heard: no script listens for recoil yet. Press F5 to stop.

The events, as this chapter leaves them

Check it works