sanspie
1f47880e8a
Document the default Design layout, agent mentions and follow controls, curve preset editing, and Scene View lighting toggles in English and Russian.
121 lines
4.1 KiB
Markdown
121 lines
4.1 KiB
Markdown
---
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id: curves
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icon: vec.angular
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group: gameplay
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title: Curves
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order: 4
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---
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# Curves
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A curve maps time to a value. Component fields of type `curve.Curve` describe falloffs, speed ramps and fades; a tween can follow a curve instead of an easing.
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---
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id: curves/shape
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icon: code.hints
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parent: curves
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order: 1
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title: Presets and keys
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---
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# Presets and keys
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A curve is either a preset or a list of keys. A preset is quick to pick; keys give any shape.
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## Presets
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A preset is an easing on time `0..1`: `linear` and the `in`/`out`/`inOut` family of quad, cubic, sine, expo, back, elastic and bounce.
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## Keys
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Each key has a time, a value, two slopes, a segment mode and a tangent mode.
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| Segment | From this key to the next |
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|---|---|
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| Bezier | smooth, shaped by the slopes |
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| Linear | a straight line |
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| Step | holds this key's value |
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| Tangent | Slopes |
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|---|---|
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| Auto | follow the neighbours and never overshoot them |
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| Linear | point at the neighbouring keys |
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| Free | set by hand; In and Out may differ |
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**Before** and **After** decide what happens outside the keys: `Clamp` holds the end value, `Loop` repeats, `Ping-pong` repeats mirrored. Curves are float32 and evaluate identically on every platform.
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---
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id: curves/editor
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icon: edit.rename
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parent: curves
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order: 2
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title: Editing curves
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---
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# Editing curves
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The Inspector draws the curve inside the field; a click opens the curve editor.
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- **Preset** switches between presets and **Keys**. Choosing Keys on a preset approximates its shape with editable keys. You can also drag the preset curve directly: moving it converts the preset to keys and moves the selected point.
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- **Double-click** the graph to add a key on the curve, **right-click** a key to remove it, drag a key or a slope handle to change it.
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- Hold **Ctrl** (Cmd on macOS) to snap to a 1/20 grid of the view, hold **Shift** while dragging a slope handle to move one side only.
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- **Time**, **Value**, **Segment** and **Tangent** edit the selected key; dragging a handle makes its tangent Free.
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Every drag is one undo step. Undoing a preset drag restores the original preset; Redo restores the edited keys. Prefab instances show an overridden curve like any other field.
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---
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id: curves/scripts
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icon: file.script
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parent: curves
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order: 3
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title: Curves in scripts
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---
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# Curves in scripts
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A script reads a curve field of a component and evaluates it with `aego/curve`:
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import "aego/curve"
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func Update(dt float) {
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age += dt
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fade := node.Get<Fader>().Alpha
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sr.Tint.A = curve.Eval(fade, age / curve.Duration(fade))
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}
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| Function | |
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|---|---|
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| `Eval(c, t) float` | the value at `t`, wrapped by Before and After |
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| `EvalClamped(c, t) float` | the value at `t` clamped to the first and last key |
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| `Duration(c) float` | time from the first to the last key, 1 for a preset |
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| `Ease(e, t) float` | a preset easing at `t` clamped to `0..1` |
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The constants `curve.Linear`, `curve.OutQuad` and the rest have the type `curve.Easing` and are the `ease` argument of tweens.
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A `Curve` value is a read-only view of the field, not a copy: it sees edits made after it was read. Scripts cannot build curves or export curve fields. A view whose node or component is gone faults with `AES6004`.
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---
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id: curves/go
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icon: code.brackets
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parent: curves
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order: 4
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title: Curves in Go
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---
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# Curves in Go
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type Fader struct {
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Alpha curve.Curve `aego:"alpha"`
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}
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c := curve.Keyed(curve.Key{T: 0, V: 1}, curve.Key{T: 0.5, V: 1, Interp: curve.InterpLinear}, curve.Key{T: 1, V: 0})
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v := c.Eval(0.75)
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| Function | |
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|---|---|
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| `FromEasing(e)`, `Line(t0, v0, t1, v1)`, `Constant(v)`, `Keyed(keys...)` | construction |
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| `Eval`, `EvalClamped`, `Span`, `Duration`, `Range(samples)` | reading |
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| `Fix`, `Smooth`, `Normalize`, `Bake(samples)` | editing helpers |
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`Keyed` and `Fix` sort the keys, drop keys with NaN and keep the last of two keys at the same time. Change `Keys` directly only together with `Fix` or `Smooth`.
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In scenes and prefabs a curve is written as a struct; defaults are omitted and a preset has no keys:
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falloff={ ease=outQuad post=pingPong }
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alpha={ keys=[[0, 1, 0, 0, bezier, auto], [1, 0, -2, -2, linear, free]] }
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