Merge pull request #1895 from ki2pixel/mute-keyframes

Keyframes: mute keyframes without deleting them (#1894)

crates/engine/src/cmd/prop.rs

@@ -1189,6 +1189,15 @@ fn toggle_hold(s: &mut Session, _: &Value) -> Result<Value> {
     })
 }
 
+fn set_muted(s: &mut Session, p: &Value) -> Result<Value> {
+    let muted = b_p(p, "muted").unwrap_or(true);
+    let label = if muted { "Mute Keyframes" } else { "Unmute Keyframes" };
+    edit_keys(s, label, None, move |keys, i, _| {
+        keys[i].muted = muted;
+        false
+    })
+}
+
 /// A number or a per-dimension array of numbers.
 fn nums_p(p: &Value, k: &str, scale: f64) -> Option<Vec<f64>> {
     match p.get(k)? {
@@ -1381,6 +1390,7 @@ pub fn specs() -> Vec<CommandSpec> {
             &json!({"which": "out"})
         )),
         cmd!("keys.toggleHold", "Toggle Hold Keyframe", ["Animation"], Some("Cmd+Alt+H"), "{}", has_keys, toggle_hold),
+        cmd!("keys.setMuted", "Mute Keyframes", ["Animation"], None, "{muted?: bool (default true)}", has_keys, set_muted),
         cmd!(
             "keys.interpolation",
             "Keyframe Interpolation...",

crates/engine/src/menus.rs

@@ -1036,6 +1036,8 @@ Animation
   ---
   Add Keyframe | anim.addKeyframe
   Toggle Hold Keyframe | keys.toggleHold
+  Mute Keyframes | keys.setMuted
+  Unmute Keyframes | keys.setMuted {"muted":false}
   Keyframe Interpolation... | keys.interpolation
   Keyframe Velocity... | keys.velocity
   Keyframe Assistant

crates/engine/src/tests/menu_cmds.rs

@@ -1483,6 +1483,68 @@ fn key_selection_toggles_and_skips_locked_layers_and_hold_restores_bezier() {
     assert!(s.state.selected_keys.is_empty());
 }
 
+#[test]
+fn muting_keys_skips_them_in_the_timeline_value_and_undoes() {
+    let mut s = comp();
+    let a = solid(&mut s, "#ff0000");
+    for (t, v) in [(0.0, 0.0), (1.0, 100.0), (2.0, 300.0)] {
+        s.execute("prop.addKey", json!({"layer": a, "path": "transform/opacity", "time": t, "value": v})).unwrap();
+    }
+    let value_at = |s: &Session, t: f64| layer(s, a).props.prop("transform/opacity").unwrap().value_at(Tick::from_seconds_f64(t)).as_f64();
+    let select = |s: &mut Session| s.execute("keys.select", json!({"keys": [{"layer": a, "path": "transform/opacity", "time": 1.0}]})).unwrap();
+    select(&mut s);
+    let before = value_at(&s, 0.5);
+    s.execute("keys.setMuted", json!({"muted": true})).unwrap();
+    assert!(layer(&s, a).props.prop("transform/opacity").unwrap().keys[1].muted);
+    // The muted key no longer bends the 0 → 300 segment.
+    assert!((value_at(&s, 0.5) - 75.0).abs() < 1e-6);
+    assert!((value_at(&s, 1.5) - 225.0).abs() < 1e-6);
+    s.undo();
+    assert!(!layer(&s, a).props.prop("transform/opacity").unwrap().keys[1].muted);
+    assert!((value_at(&s, 0.5) - before).abs() < 1e-6);
+    // The same command unmutes.
+    select(&mut s);
+    s.execute("keys.setMuted", json!({"muted": true})).unwrap();
+    s.execute("keys.setMuted", json!({"muted": false})).unwrap();
+    assert!(!layer(&s, a).props.prop("transform/opacity").unwrap().keys[1].muted);
+}
+
+/// Both Animation-menu rows mute and unmute through `Session::execute`, and undo/redo work.
+#[test]
+fn mute_and_unmute_keyframes_menu_rows_work_and_undo() {
+    fn rows(nodes: &[crate::menus::MenuNode], out: &mut Vec<(String, Value)>) {
+        for n in nodes {
+            match n {
+                crate::menus::MenuNode::Item(e) if e.command == "keys.setMuted" => out.push((e.label.clone(), e.params.clone())),
+                crate::menus::MenuNode::Submenu { children, .. } => rows(children, out),
+                _ => {}
+            }
+        }
+    }
+    let mut menu = vec![];
+    rows(&crate::menus::parse(crate::menus::TREE, false).unwrap(), &mut menu);
+    assert_eq!(menu.iter().map(|(l, _)| l.as_str()).collect::<Vec<_>>(), ["Mute Keyframes", "Unmute Keyframes"], "{menu:?}");
+
+    let mut s = comp();
+    let a = solid(&mut s, "#ff0000");
+    for (t, v) in [(0.0, 0.0), (1.0, 100.0)] {
+        s.execute("prop.addKey", json!({"layer": a, "path": "transform/opacity", "time": t, "value": v})).unwrap();
+    }
+    let muted = |s: &Session| layer(s, a).props.prop("transform/opacity").unwrap().keys[1].muted;
+    s.execute("keys.select", json!({"keys": [{"layer": a, "path": "transform/opacity", "time": 1.0}]})).unwrap();
+    let run = |s: &mut Session, params: &Value| {
+        s.execute("keys.setMuted", if params.is_null() { json!({}) } else { params.clone() }).unwrap();
+    };
+    run(&mut s, &menu[0].1);
+    assert!(muted(&s));
+    s.undo();
+    assert!(!muted(&s));
+    s.redo();
+    assert!(muted(&s));
+    run(&mut s, &menu[1].1);
+    assert!(!muted(&s));
+}
+
 #[test]
 fn transform_drags_apply_their_whole_offset_to_the_keys_they_started_with() {
     let mut s = comp();

crates/interchange/src/export.rs

@@ -155,12 +155,7 @@ fn unsupported(project: &Project, comp: &Comp, l: &Layer, format: TimelineFormat
         return Some(format!("blend mode {}", l.blend_mode.label()));
     }
     // Premiere's Basic Motion in the interchange formats has one (uniform) scale.
-    if let Some(s) = l.transform().and_then(|t| t.get("scale"))
-        && std::iter::once(&s.value).chain(s.keys.iter().map(|k| &k.value)).any(|v| {
-            let a = v.as_vec3();
-            (a[0] - a[1]).abs() > 1e-9
-        })
-    {
+    if l.transform().and_then(|t| t.get("scale")).is_some_and(non_uniform_scale) {
         return Some("non-uniform scale".into());
     }
     if l.preserve_transparency {
@@ -581,10 +576,7 @@ impl Exporter<'_> {
             }
         }
         if let Some(p) = tr.get("scale") {
-            let uniform = std::iter::once(&p.value).chain(p.keys.iter().map(|k| &k.value)).all(|v| {
-                let a = v.as_vec3();
-                (a[0] - a[1]).abs() < 1e-9
-            });
+            let uniform = !non_uniform_scale(p);
             m.params.insert("scale".into(), param_out(p, &to_clip, |v| fp::ParamValue::Float(v.as_vec3()[1])));
             if !uniform {
                 m.params.insert("scale_width".into(), param_out(p, &to_clip, |v| fp::ParamValue::Float(v.as_vec3()[0])));
@@ -636,6 +628,16 @@ fn differs(v: &Value, def: [f64; 2]) -> bool {
     (a[0] - def[0]).abs() > 1e-6 || (a[1] - def[1]).abs() > 1e-6
 }
 
+/// Whether a scale property is non-uniform at some point: active key values, or the static
+/// value when every key is muted (muted keys are not exported, #1894).
+fn non_uniform_scale(p: &Property) -> bool {
+    let non_uniform = |v: &Value| {
+        let a = v.as_vec3();
+        (a[0] - a[1]).abs() > 1e-9
+    };
+    if p.keys.iter().any(|k| !k.muted) { p.keys.iter().filter(|k| !k.muted).any(|k| non_uniform(&k.value)) } else { non_uniform(&p.value) }
+}
+
 /// The clip's `id` effect, or a new instance of it (None if the registry has no such effect).
 fn effect_or_new(ti: &fp::TrackItem, id: &str) -> Option<fp::EffectInstance> {
     ti.effect(id).cloned().or_else(|| fp::find_effect(id).map(|e| e.instance()))
@@ -651,7 +653,9 @@ fn set_effect(ti: &mut fp::TrackItem, e: fp::EffectInstance) {
 /// A property → a FilmCraft parameter (layer-time keys → clip-time keys).
 fn param_out(p: &Property, to_clip: &impl Fn(Tick) -> filmcraft_time::Tick, conv: impl Fn(&Value) -> fp::ParamValue) -> fp::Param {
     let mut out = fp::Param::new(conv(&p.value));
-    for k in &p.keys {
+    // XML timelines have no mute state: leave muted keys out, as the Lottie exporter does, so
+    // the exported animation matches what the renderer shows (#1894).
+    for k in p.keys.iter().filter(|k| !k.muted) {
         let mut fk = fp::Keyframe::new(to_clip(k.time), conv(&k.value));
         fk.interp = match k.out_interp {
             Interp::Linear => fp::Interpolation::Linear,

crates/interchange/src/tests.rs

@@ -480,6 +480,59 @@ fn tr_orig(l: &Layer) -> &effectcraft_project::Property {
     l.transform().unwrap().get("position").unwrap()
 }
 
+/// #1894: XML timelines have no mute state, so a muted key must not be written as a keyframe
+/// (the export would otherwise animate through it).
+#[test]
+fn export_skips_muted_keyframes() {
+    let mut p = Project::default();
+    let a = footage_item(&mut p, "/media/a.mov");
+    let mut c = Comp::new(W, H, FrameRate::new(25, 1), t(4.0));
+    let mut l = effectcraft_project::build::layer(&mut p, &c, "clip", LayerSource::Footage { item: a }, (W, H), None);
+    {
+        let pos = l.transform_mut().unwrap().get_mut("position").unwrap();
+        pos.keys = vec![
+            Keyframe::new(t(0.0), Value::Vec3([100.0, 120.0, 0.0])),
+            Keyframe::new(t(1.0), Value::Vec3([500.0, 240.0, 0.0])),
+            Keyframe::new(t(2.0), Value::Vec3([300.0, 60.0, 0.0])),
+        ];
+        pos.keys[1].muted = true;
+    }
+    c.layers.push(l);
+    let cid = comp_item(&mut p, "Main", c);
+    let out = export(&p, cid, &ExportOptions { format: TimelineFormat::Fcp7Xml, ..Default::default() }, &HashMap::new()).unwrap();
+    let (q, r) = import_doc(&out.bytes, "Main.xml", &mut probe);
+    let main = r.comps.iter().copied().find(|c| q.item(*c).unwrap().name == "Main").expect("Main");
+    let pos = layer(q.comp(main).unwrap(), "clip").transform().unwrap().get("position").unwrap();
+    assert_eq!(pos.keys.len(), 2, "the muted key was exported");
+    assert_eq!(pos.keys[0].value.as_vec3()[0], 100.0);
+    assert_eq!(pos.keys[1].value.as_vec3()[0], 300.0);
+}
+
+/// #1894: a muted non-uniform scale key must not force a uniform layer to pre-render; only the
+/// active keys matter, and the static value when every key is muted.
+#[test]
+fn muted_non_uniform_scale_does_not_force_prerendering() {
+    let mut p = Project::default();
+    let a = footage_item(&mut p, "/media/a.mov");
+    let mut c = Comp::new(W, H, FrameRate::new(25, 1), t(2.0));
+    let mut l = effectcraft_project::build::layer(&mut p, &c, "clip", LayerSource::Footage { item: a }, (W, H), None);
+    {
+        let scale = l.transform_mut().unwrap().get_mut("scale").unwrap();
+        scale.keys = vec![Keyframe::new(t(0.0), Value::Vec3([100.0, 100.0, 100.0])), Keyframe::new(t(1.0), Value::Vec3([50.0, 200.0, 100.0]))];
+        scale.keys[1].muted = true;
+    }
+    let lid = l.id;
+    c.layers.push(l);
+    let cid = comp_item(&mut p, "Main", c);
+    assert_eq!(prerender_reason(&p, cid, lid, &ExportOptions::default()), None);
+    // With every key muted the static value drives evaluation, so a non-uniform static scale
+    // still takes the flattened path.
+    let scale = p.comp_mut(cid).unwrap().layer_mut(lid).unwrap().transform_mut().unwrap().get_mut("scale").unwrap();
+    scale.keys[0].muted = true;
+    scale.value = Value::Vec3([50.0, 200.0, 100.0]);
+    assert_eq!(prerender_reason(&p, cid, lid, &ExportOptions::default()).as_deref(), Some("non-uniform scale"));
+}
+
 #[test]
 fn export_without_prerender_leaves_text_out() {
     let (p, cid) = ae_project();

crates/keyframe/src/lib.rs

@@ -15,6 +15,7 @@ pub mod value;
 
 use effectcraft_time::{TICKS_PER_SECOND, Tick};
 use serde::{Deserialize, Serialize};
+use std::borrow::Borrow;
 pub use text_doc::{BaselineOption, CharStyle, Composer, Direction, FigureStyle, FigureWidth, Kerning, LineJoin, OpenType, ParaStyle, StyleRun};
 pub use value::{FeatherPoint, Gradient, Justify, ShapePath, TextDoc, Value};
 
@@ -89,12 +90,19 @@ pub struct Keyframe {
     /// Keyframe color label: index into the label list (0 = None).
     #[serde(default, skip_serializing_if = "is_zero")]
     pub label: u8,
+    /// Muted keys stay in the list (and the UI) but evaluation skips them.
+    #[serde(default, skip_serializing_if = "is_false")]
+    pub muted: bool,
 }
 
 fn is_zero(v: &u8) -> bool {
     *v == 0
 }
 
+fn is_false(v: &bool) -> bool {
+    !*v
+}
+
 fn yes() -> bool {
     true
 }
@@ -116,6 +124,7 @@ impl Keyframe {
             spatial_continuous: false,
             roving: false,
             label: 0,
+            muted: false,
         }
     }
     pub fn hold(mut self) -> Keyframe {
@@ -320,16 +329,16 @@ fn v3(v: &Value) -> [f64; 3] {
 /// tangent is a sixth of the way from the previous key to the next, the in tangent its mirror, and
 /// key times play no part. An end key uses its one neighbour, so the path leaves the first key
 /// and enters the last one toward the neighbouring key instead of with no tangent.
-fn auto_spatial(keys: &[Keyframe], i: usize) -> ([f64; 3], [f64; 3]) {
+fn auto_spatial<K: Borrow<Keyframe>>(keys: &[K], i: usize) -> ([f64; 3], [f64; 3]) {
     if i >= keys.len() || keys.len() < 2 {
         return ([0.0; 3], [0.0; 3]);
     }
-    let a = v3(&keys[i.saturating_sub(1)].value);
-    let c = v3(&keys[(i + 1).min(keys.len() - 1)].value);
+    let a = v3(&keys[i.saturating_sub(1)].borrow().value);
+    let c = v3(&keys[(i + 1).min(keys.len() - 1)].borrow().value);
     let tout = [(c[0] - a[0]) / 6.0, (c[1] - a[1]) / 6.0, (c[2] - a[2]) / 6.0];
     // A side facing a key at the same position gets no tangent, so the segment between two
     // identical keys has zero length and the layer holds still (#1675).
-    let p = v3(&keys[i].value);
+    let p = v3(&keys[i].borrow().value);
     let tin = if i > 0 && a == p { [0.0; 3] } else { [-tout[0], -tout[1], -tout[2]] };
     let tout = if i + 1 < keys.len() && c == p { [0.0; 3] } else { tout };
     (tin, tout)
@@ -337,7 +346,12 @@ fn auto_spatial(keys: &[Keyframe], i: usize) -> ([f64; 3], [f64; 3]) {
 
 /// Effective spatial tangents of key `i` (auto or stored).
 pub fn spatial_tangents(keys: &[Keyframe], i: usize) -> ([f64; 3], [f64; 3]) {
-    let Some(key) = keys.get(i) else { return ([0.0; 3], [0.0; 3]) };
+    tangents_of(keys, i)
+}
+
+/// [`spatial_tangents`] over stored keys or a filtered list of them (see [`evaluate`]).
+fn tangents_of<K: Borrow<Keyframe>>(keys: &[K], i: usize) -> ([f64; 3], [f64; 3]) {
+    let Some(key) = keys.get(i).map(Borrow::borrow) else { return ([0.0; 3], [0.0; 3]) };
     if key.spatial_auto { auto_spatial(keys, i) } else { (key.spatial_in, key.spatial_out) }
 }
 
@@ -373,18 +387,18 @@ pub fn spatial_handles(keys: &[Keyframe], i: usize) -> ([f64; 3], [f64; 3]) {
 }
 
 /// Effective temporal ease of key `i` for dimension `d` (auto-Bezier keys get the neighbour slope).
-fn effective_ease(keys: &[Keyframe], i: usize, d: usize, spatial: bool, out: bool) -> Ease {
-    let k = &keys[i];
+fn effective_ease<K: Borrow<Keyframe>>(keys: &[K], i: usize, d: usize, spatial: bool, out: bool) -> Ease {
+    let k = keys[i].borrow();
     let list = if out { &k.out_ease } else { &k.in_ease };
     if k.auto_bezier && i > 0 && i + 1 < keys.len() {
-        let dt = secs(keys[i + 1].time) - secs(keys[i - 1].time);
+        let dt = secs(keys[i + 1].borrow().time) - secs(keys[i - 1].borrow().time);
         let slope = if spatial {
-            let a = v3(&keys[i - 1].value);
-            let c = v3(&keys[i + 1].value);
+            let a = v3(&keys[i - 1].borrow().value);
+            let c = v3(&keys[i + 1].borrow().value);
             ((c[0] - a[0]).powi(2) + (c[1] - a[1]).powi(2) + (c[2] - a[2]).powi(2)).sqrt() / dt.max(1e-12)
         } else {
-            let a = keys[i - 1].value.components();
-            let c = keys[i + 1].value.components();
+            let a = keys[i - 1].borrow().value.components();
+            let c = keys[i + 1].borrow().value.components();
             (c.get(d).unwrap_or(&0.0) - a.get(d).unwrap_or(&0.0)) / dt.max(1e-12)
         };
         return Ease { speed: slope, influence: 1.0 / 6.0 };
@@ -508,23 +522,39 @@ pub fn time_reverse(keys: &mut [Keyframe]) {
 }
 
 /// Evaluate a keyframed property at `t`. `spatial` selects motion-path semantics for 2D/3D values.
+/// Muted keys are skipped, so the active neighbours interpolate as if they were not there; `None`
+/// means every key is muted (the property's static value applies).
 pub fn evaluate(keys: &[Keyframe], t: Tick, spatial: bool) -> Option<Value> {
-    let first = keys.first()?;
+    if !keys.iter().any(|k| k.muted) {
+        return evaluate_active(keys, t, spatial);
+    }
+    // Muting is rare: skip the muted keys by reference rather than copying every key and value.
+    let active: Vec<&Keyframe> = keys.iter().filter(|k| !k.muted).collect();
+    evaluate_active(&active, t, spatial)
+}
+
+fn evaluate_active<K: Borrow<Keyframe>>(keys: &[K], t: Tick, spatial: bool) -> Option<Value> {
+    let first = keys.first()?.borrow();
     if keys.len() == 1 || t <= first.time {
         return Some(first.value.clone());
     }
-    let last = keys.last()?;
+    let last = keys.last()?.borrow();
     if t >= last.time {
         return Some(last.value.clone());
     }
-    let i = keys.partition_point(|k| k.time <= t) - 1;
-    Some(segment_value(keys, i, t, spatial))
+    let i = keys.partition_point(|k| k.borrow().time <= t) - 1;
+    Some(segment_value_of(keys, i, t, spatial))
 }
 
 /// Value inside segment `i` → `i+1` at time `t`.
 pub fn segment_value(keys: &[Keyframe], i: usize, t: Tick, spatial: bool) -> Value {
-    let a = &keys[i];
-    let b = &keys[i + 1];
+    segment_value_of(keys, i, t, spatial)
+}
+
+/// [`segment_value`] over stored keys or a filtered list of them (see [`evaluate`]).
+fn segment_value_of<K: Borrow<Keyframe>>(keys: &[K], i: usize, t: Tick, spatial: bool) -> Value {
+    let a = keys[i].borrow();
+    let b = keys[i + 1].borrow();
     if a.out_interp == Interp::Hold || !a.value.interpolates() {
         return a.value.clone();
     }
@@ -539,8 +569,8 @@ pub fn segment_value(keys: &[Keyframe], i: usize, t: Tick, spatial: bool) -> Val
     if is_spatial {
         let p0 = v3(&a.value);
         let p3 = v3(&b.value);
-        let (_, out_t) = spatial_tangents(keys, i);
-        let (in_t, _) = spatial_tangents(keys, i + 1);
+        let (_, out_t) = tangents_of(keys, i);
+        let (in_t, _) = tangents_of(keys, i + 1);
         let seg = SpatialSeg::new([p0, [p0[0] + out_t[0], p0[1] + out_t[1], p0[2] + out_t[2]], [p3[0] + in_t[0], p3[1] + in_t[1], p3[2] + in_t[2]], p3]);
         let len = seg.length();
         let f = if lin_out && lin_in || len <= 1e-12 {
@@ -617,6 +647,7 @@ pub fn set_key(keys: &mut Vec<Keyframe>, key: Keyframe) -> usize {
             k.spatial_continuous = old.spatial_continuous;
             k.roving = old.roving;
             k.label = old.label;
+            k.muted = old.muted;
             keys[i] = k;
             i
         }

crates/keyframe/src/tests.rs

@@ -395,3 +395,59 @@ proptest::proptest! {
         proptest::prop_assert!((-1e-9..=10.0 + 1e-9).contains(&v));
     }
 }
+
+#[test]
+fn muted_keys_are_skipped_by_evaluation() {
+    let mut keys = vec![Keyframe::new(s(0.0), Value::Scalar(0.0)), Keyframe::new(s(1.0), Value::Scalar(100.0)), Keyframe::new(s(2.0), Value::Scalar(300.0))];
+    let at = |keys: &[Keyframe], t: f64| evaluate(keys, s(t), false).unwrap().as_f64();
+    assert!((at(&keys, 0.5) - 50.0).abs() < 1e-9);
+    assert!((at(&keys, 1.5) - 200.0).abs() < 1e-9);
+    keys[1].muted = true;
+    // The 0 → 300 segment now spans 0 → 2 s.
+    assert!((at(&keys, 0.5) - 75.0).abs() < 1e-9);
+    assert!((at(&keys, 1.0) - 150.0).abs() < 1e-9);
+    assert!((at(&keys, 1.5) - 225.0).abs() < 1e-9);
+    for k in &mut keys {
+        k.muted = true;
+    }
+    assert!(evaluate(&keys, s(0.5), false).is_none());
+}
+
+#[test]
+fn muted_key_automation_uses_the_active_neighbours() {
+    let mut keys = vec![
+        Keyframe::new(s(0.0), Value::Vec2([0.0, 0.0])),
+        Keyframe::new(s(1.0), Value::Vec2([50.0, 100.0])),
+        Keyframe::new(s(2.0), Value::Vec2([100.0, 0.0])),
+    ];
+    for k in &mut keys {
+        k.auto_bezier = true;
+        k.in_interp = Interp::Bezier;
+        k.out_interp = Interp::Bezier;
+    }
+    let all = keys.clone();
+    let mut active = keys.clone();
+    active.remove(1);
+    keys[1].muted = true;
+    for t in [0.0, 0.25, 0.5, 1.0, 1.5, 1.75, 2.0] {
+        assert_eq!(evaluate(&keys, s(t), true), evaluate(&active, s(t), true), "{t}");
+    }
+    // The muted auto-Bezier key no longer bulges the motion path.
+    assert_ne!(evaluate(&keys, s(0.5), true), evaluate(&all, s(0.5), true));
+}
+
+#[test]
+fn mute_round_trips_and_survives_value_replacement() {
+    let mut k = Keyframe::new(s(0.0), Value::Scalar(1.0));
+    let json = serde_json::to_value(&k).unwrap();
+    assert!(json.get("muted").is_none(), "false is the default and is skipped");
+    k.muted = true;
+    let json = serde_json::to_value(&k).unwrap();
+    assert_eq!(json["muted"], serde_json::json!(true));
+    let back: Keyframe = serde_json::from_value(json).unwrap();
+    assert!(back.muted);
+    let mut keys = vec![k];
+    set_key(&mut keys, Keyframe::new(s(0.0), Value::Scalar(2.0)));
+    assert!(keys[0].muted);
+    assert_eq!(keys[0].value, Value::Scalar(2.0));
+}

crates/lottie/src/anim.rs

@@ -73,9 +73,22 @@ fn is_spatial(p: &Property) -> bool {
 }
 
 /// Export a property as a Lottie animatable property (`{a, k}` plus `x` for expressions).
-/// `label` names the property in warnings.
+/// `label` names the property in warnings. Muted keys are omitted: Lottie has no mute state, and
+/// the remaining keys carry the animation the renderer shows.
 pub(crate) fn export_prop(ex: &mut Ex, p: &Property, conv: &dyn Fn(&Value) -> Json, label: &str) -> Json {
-    let mut out = if p.keys.is_empty() { json!({"a": 0, "k": conv(&p.value)}) } else { json!({"a": 1, "k": export_keys(ex, p, conv)}) };
+    let muted = p.keys.iter().any(|k| k.muted);
+    if muted {
+        ex.warn(format!("{label}: muted keyframes are not exported"));
+    }
+    let active: Vec<Keyframe>;
+    let keys: &[Keyframe] = if muted {
+        active = p.keys.iter().filter(|k| !k.muted).cloned().collect();
+        &active
+    } else {
+        &p.keys
+    };
+    let mut out =
+        if keys.is_empty() { json!({"a": 0, "k": conv(&p.value)}) } else { json!({"a": 1, "k": export_keys(ex, keys, is_spatial(p), p.hold_only, conv)}) };
     if let Some(e) = p.expr.as_ref().filter(|e| e.enabled && !e.text.trim().is_empty()) {
         if ex.include_expressions {
             out["x"] = json!(e.text);
@@ -86,20 +99,18 @@ pub(crate) fn export_prop(ex: &mut Ex, p: &Property, conv: &dyn Fn(&Value) -> Js
     out
 }
 
-fn export_keys(ex: &Ex, p: &Property, conv: &dyn Fn(&Value) -> Json) -> Vec<Json> {
-    let keys = &p.keys;
-    let spatial = is_spatial(p);
+fn export_keys(ex: &Ex, keys: &[Keyframe], spatial: bool, hold_only: bool, conv: &dyn Fn(&Value) -> Json) -> Vec<Json> {
     let mut out = Vec::with_capacity(keys.len());
     for (i, k) in keys.iter().enumerate() {
         let mut o = json!({"t": r6(ex.tb.frame(k.time)), "s": wrap(conv(&k.value))});
         if i + 1 == keys.len() {
-            if k.out_interp == Interp::Hold || p.hold_only {
+            if k.out_interp == Interp::Hold || hold_only {
                 o["h"] = json!(1);
             }
             out.push(o);
             continue;
         }
-        if k.out_interp == Interp::Hold || p.hold_only || !k.value.interpolates() {
+        if k.out_interp == Interp::Hold || hold_only || !k.value.interpolates() {
             o["h"] = json!(1);
             out.push(o);
             continue;

crates/lottie/src/tests.rs

@@ -878,3 +878,21 @@ fn external_images_are_local_or_skipped() {
     assert_eq!(std::path::Path::new(&paths[0]), base.join("images").join("a.png"));
     assert_eq!(r.warnings.iter().filter(|w| w.contains("is not imported")).count(), assets.len() - 1, "{:?}", r.warnings);
 }
+
+#[test]
+fn muted_keys_are_omitted_from_the_export() {
+    let (mut p, cid) = setup();
+    let mut l = solid_layer(&mut p, cid, [0.0, 1.0, 0.0], 20, 20);
+    let mut b = Keyframe::new(s(1.0), Value::Scalar(100.0));
+    b.muted = true;
+    l.props.prop_mut("transform/opacity").unwrap().keys = vec![Keyframe::new(s(0.0), Value::Scalar(0.0)), b, Keyframe::new(s(2.0), Value::Scalar(300.0))];
+    push(&mut p, cid, l);
+    let (q, nc, warnings, json) = roundtrip(&p, cid, &ExportOptions::default());
+    assert!(warnings.iter().any(|w| w.contains("muted keyframes")), "{warnings:?}");
+    // Lottie has no mute state: the two active keys carry the 0 → 300 animation.
+    assert_eq!(json["layers"][0]["ks"]["o"]["k"].as_array().unwrap().len(), 2);
+    assert_eq!(json["layers"][0]["ks"]["o"]["k"][1]["s"], json!([300.0]));
+    let opacity_at = |p: &Project, cid: ItemId, t: f64| p.comp(cid).unwrap().layers[0].props.prop("transform/opacity").unwrap().value_at(s(t)).as_f64();
+    assert!((opacity_at(&p, cid, 1.0) - 150.0).abs() < 1e-6);
+    assert!((opacity_at(&q, nc, 1.0) - 150.0).abs() < 1e-6);
+}

crates/ui-egui/src/i18n.rs

@@ -836,6 +836,8 @@ const SIMPLIFIED_CHINESE: &[(&str, &str, &str)] = &[
     ("layer.applyTextPreset", "Drop In Lines", "行落下"),
     ("anim.addKeyframe", "Add Keyframe", "添加关键帧"),
     ("keys.toggleHold", "Toggle Hold Keyframe", "切换定格关键帧"),
+    ("keys.setMuted", "Mute Keyframes", "静音关键帧"),
+    ("keys.setMuted", "Unmute Keyframes", "取消静音关键帧"),
     ("keys.interpolation", "Keyframe Interpolation...", "关键帧插值..."),
     ("keys.velocity", "Keyframe Velocity...", "关键帧速度..."),
     ("", "Keyframe Assistant", "关键帧辅助"),
@@ -1472,6 +1474,8 @@ const TRADITIONAL_CHINESE: &[(&str, &str, &str)] = &[
     ("layer.applyTextPreset", "Drop In Lines", "行落下"),
     ("anim.addKeyframe", "Add Keyframe", "新增關鍵影格"),
     ("keys.toggleHold", "Toggle Hold Keyframe", "切換定格關鍵影格"),
+    ("keys.setMuted", "Mute Keyframes", "靜音關鍵影格"),
+    ("keys.setMuted", "Unmute Keyframes", "取消靜音關鍵影格"),
     ("keys.interpolation", "Keyframe Interpolation...", "關鍵影格插補..."),
     ("keys.velocity", "Keyframe Velocity...", "關鍵影格速度..."),
     ("", "Keyframe Assistant", "關鍵影格輔助"),
@@ -2105,6 +2109,8 @@ const JAPANESE: &[(&str, &str, &str)] = &[
     ("layer.applyTextPreset", "Drop In Lines", "行をドロップイン"),
     ("anim.addKeyframe", "Add Keyframe", "キーフレームを追加"),
     ("keys.toggleHold", "Toggle Hold Keyframe", "停止したキーフレームの切り替え"),
+    ("keys.setMuted", "Mute Keyframes", "キーフレームをミュート"),
+    ("keys.setMuted", "Unmute Keyframes", "キーフレームのミュートを解除"),
     ("keys.interpolation", "Keyframe Interpolation...", "キーフレーム補間法..."),
     ("keys.velocity", "Keyframe Velocity...", "キーフレーム速度..."),
     ("", "Keyframe Assistant", "キーフレーム補助"),
@@ -2741,6 +2747,8 @@ const UKRAINIAN: &[(&str, &str, &str)] = &[
     ("layer.applyTextPreset", "Drop In Lines", "Поява рядків згори"),
     ("anim.addKeyframe", "Add Keyframe", "Додати ключовий кадр"),
     ("keys.toggleHold", "Toggle Hold Keyframe", "Перемкнути утримання ключового кадру"),
+    ("keys.setMuted", "Mute Keyframes", "Заглушити ключові кадри"),
+    ("keys.setMuted", "Unmute Keyframes", "Зняти заглушення ключових кадрів"),
     ("keys.interpolation", "Keyframe Interpolation...", "Інтерполяція ключових кадрів..."),
     ("keys.velocity", "Keyframe Velocity...", "Швидкість ключових кадрів..."),
     ("", "Keyframe Assistant", "Помічник ключових кадрів"),
@@ -3378,6 +3386,8 @@ const SPANISH: &[(&str, &str, &str)] = &[
     ("layer.applyTextPreset", "Drop In Lines", "Entrada de líneas cayendo"),
     ("anim.addKeyframe", "Add Keyframe", "Añadir fotograma clave"),
     ("keys.toggleHold", "Toggle Hold Keyframe", "Conmutar mantener fotograma clave"),
+    ("keys.setMuted", "Mute Keyframes", "Silenciar fotogramas clave"),
+    ("keys.setMuted", "Unmute Keyframes", "Reactivar fotogramas clave"),
     ("keys.interpolation", "Keyframe Interpolation...", "Interpolación de fotogramas clave..."),
     ("keys.velocity", "Keyframe Velocity...", "Velocidad de fotogramas clave..."),
     ("", "Keyframe Assistant", "Asistente de fotogramas clave"),
@@ -4013,6 +4023,8 @@ const PORTUGUESE: &[(&str, &str, &str)] = &[
     ("layer.applyTextPreset", "Drop In Lines", "Entrar com queda de linhas"),
     ("anim.addKeyframe", "Add Keyframe", "Adicionar quadro-chave"),
     ("keys.toggleHold", "Toggle Hold Keyframe", "Alternar quadro-chave de retenção"),
+    ("keys.setMuted", "Mute Keyframes", "Silenciar quadros-chave"),
+    ("keys.setMuted", "Unmute Keyframes", "Reativar quadros-chave"),
     ("keys.interpolation", "Keyframe Interpolation...", "Interpolação de quadro-chave..."),
     ("keys.velocity", "Keyframe Velocity...", "Velocidade do quadro-chave..."),
     ("", "Keyframe Assistant", "Assistente de quadro-chave"),
@@ -4655,6 +4667,8 @@ const RUSSIAN: &[(&str, &str, &str)] = &[
     ("layer.applyTextPreset", "Drop In Lines", "Появление строк сверху"),
     ("anim.addKeyframe", "Add Keyframe", "Добавить ключевой кадр"),
     ("keys.toggleHold", "Toggle Hold Keyframe", "Переключить фиксацию ключевого кадра"),
+    ("keys.setMuted", "Mute Keyframes", "Отключить ключевые кадры"),
+    ("keys.setMuted", "Unmute Keyframes", "Включить ключевые кадры"),
     ("keys.interpolation", "Keyframe Interpolation...", "Интерполяция ключевых кадров..."),
     ("keys.velocity", "Keyframe Velocity...", "Скорость ключевых кадров..."),
     ("", "Keyframe Assistant", "Помощник по ключевым кадрам"),
@@ -5290,6 +5304,8 @@ const FRENCH: &[(&str, &str, &str)] = &[
     ("layer.applyTextPreset", "Drop In Lines", "Chute des lignes depuis le haut"),
     ("anim.addKeyframe", "Add Keyframe", "Ajouter une image clé"),
     ("keys.toggleHold", "Toggle Hold Keyframe", "Activer/Désactiver l'image clé figée"),
+    ("keys.setMuted", "Mute Keyframes", "Désactiver les images clés"),
+    ("keys.setMuted", "Unmute Keyframes", "Réactiver les images clés"),
     ("keys.interpolation", "Keyframe Interpolation...", "Interpolation des images clés..."),
     ("keys.velocity", "Keyframe Velocity...", "Vitesse des images clés..."),
     ("", "Keyframe Assistant", "Assistant d'images clés"),
@@ -5925,6 +5941,8 @@ const GERMAN: &[(&str, &str, &str)] = &[
     ("layer.applyTextPreset", "Drop In Lines", "Zeilen fallen ein"),
     ("anim.addKeyframe", "Add Keyframe", "Keyframe hinzufügen"),
     ("keys.toggleHold", "Toggle Hold Keyframe", "Halte-Keyframe umschalten"),
+    ("keys.setMuted", "Mute Keyframes", "Keyframes stummschalten"),
+    ("keys.setMuted", "Unmute Keyframes", "Keyframes wieder aktivieren"),
     ("keys.interpolation", "Keyframe Interpolation...", "Keyframe-Interpolation..."),
     ("keys.velocity", "Keyframe Velocity...", "Keyframe-Geschwindigkeit..."),
     ("", "Keyframe Assistant", "Keyframe-Assistent"),
@@ -6561,6 +6579,8 @@ const CZECH: &[(&str, &str, &str)] = &[
     ("layer.applyTextPreset", "Drop In Lines", "Spustit řádky shora"),
     ("anim.addKeyframe", "Add Keyframe", "Přidat klíčový snímek"),
     ("keys.toggleHold", "Toggle Hold Keyframe", "Přepnout podržení klíčového snímku"),
+    ("keys.setMuted", "Mute Keyframes", "Ztlumit klíčové snímky"),
+    ("keys.setMuted", "Unmute Keyframes", "Obnovit klíčové snímky"),
     ("keys.interpolation", "Keyframe Interpolation...", "Interpolace klíčových snímků..."),
     ("keys.velocity", "Keyframe Velocity...", "Rychlost klíčového snímku..."),
     ("", "Keyframe Assistant", "Pomocník klíčových snímků"),
@@ -7192,6 +7212,8 @@ const GEORGIAN: &[(&str, &str, &str)] = &[
     ("layer.applyTextPreset", "Drop In Lines", "სტრიქონების ჩამოვარდნა"),
     ("anim.addKeyframe", "Add Keyframe", "საკვანძო კადრის დამატება"),
     ("keys.toggleHold", "Toggle Hold Keyframe", "ფიქსირებული საკვანძო კადრის გადართვა"),
+    ("keys.setMuted", "Mute Keyframes", "საკვანძო კადრების დადუმება"),
+    ("keys.setMuted", "Unmute Keyframes", "საკვანძო კადრების დადუმების მოხსნა"),
     ("keys.interpolation", "Keyframe Interpolation...", "საკვანძო კადრის ინტერპოლაცია..."),
     ("keys.velocity", "Keyframe Velocity...", "საკვანძო კადრის სიჩქარე..."),
     ("", "Keyframe Assistant", "საკვანძო კადრების ასისტენტი"),

crates/ui-egui/src/panels/graph.rs

@@ -48,9 +48,21 @@ struct KeyPt {
     t: f64,
     v: f64,
     sel: bool,
+    muted: bool,
     handles: Vec<Handle>,
 }
 
+/// A graph key's fill and edge colours: muted keys stay visible and selectable, dimmed.
+fn key_colors(t: &Tokens, edge: Color32, k: &KeyPt) -> (Color32, Color32) {
+    let fill = match (k.muted, k.sel) {
+        (true, true) => t.keyframe_selected.gamma_multiply(0.5),
+        (true, false) => Color32::from_gray(0x70),
+        (false, true) => t.keyframe_selected,
+        (false, false) => Color32::from_gray(0xe0),
+    };
+    (fill, if k.muted { edge.gamma_multiply(0.4) } else { edge })
+}
+
 struct Curve<'a> {
     layer: &'a Layer,
     prop: &'a Property,
@@ -153,7 +165,7 @@ fn curves<'a>(app: &EffectcraftApp, comp: &'a Comp, ectx: &EvalCtx, tm: TMap, pl
                     let dt = e.influence * dur * if out_side { 1.0 } else { -1.0 };
                     let (hv, show) = if speed { (e.speed.abs(), true) } else { (k.value.components().get(d).copied().unwrap_or(0.0) + e.speed * dt, !spatial) };
                     let bezier = if out_side { k.out_interp == Interp::Bezier } else { k.in_interp == Interp::Bezier };
-                    if ks && show && (bezier || speed) {
+                    if ks && !k.muted && show && (bezier || speed) {
                         handles.push(Handle { out: out_side, t: kt + dt, v: hv, speed: e.speed, dur });
                     }
                 }
@@ -162,7 +174,7 @@ fn curves<'a>(app: &EffectcraftApp, comp: &'a Comp, ectx: &EvalCtx, tm: TMap, pl
                 } else {
                     k.value.components().get(d).copied().unwrap_or(0.0)
                 };
-                keys.push(KeyPt { idx: i, time: k.time, t: kt, v, sel: ks, handles });
+                keys.push(KeyPt { idx: i, time: k.time, t: kt, v, sel: ks, muted: k.muted, handles });
             }
             out.push(Curve { layer: l, prop: pr, dim: d, color, pts, keys, editable: !spatial });
         }
@@ -522,9 +534,9 @@ pub(crate) fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painte
                 }
             }
             // The key itself.
-            let col = if k.sel { t.keyframe_selected } else { Color32::from_gray(0xe0) };
+            let (col, edge) = key_colors(&t, c.color, k);
             pc.rect_filled(Rect::from_center_size(kp, vec2(7.0, 7.0)), 0.0, col);
-            pc.rect_stroke(Rect::from_center_size(kp, vec2(7.0, 7.0)), 0.0, Stroke::new(1.0, c.color), StrokeKind::Outside);
+            pc.rect_stroke(Rect::from_center_size(kp, vec2(7.0, 7.0)), 0.0, Stroke::new(1.0, edge), StrokeKind::Outside);
             let kr = Rect::from_center_size(kp, vec2(11.0, 11.0));
             let kresp = ui.interact(kr, egui::Id::unique(("gkey", uid, d, k.idx)), Sense::click_and_drag());
             app.auto.add(&format!("timeline.graph.key.{uid}.{d}.{}", k.idx), kr, &c.prop.name);

crates/ui-egui/src/panels/timeline.rs

@@ -4111,6 +4111,7 @@ fn key_context_menu(app: &mut EffectcraftApp, g: &mut Rw, rc: &RowCtx<'_>, prop:
             ("Keyframe Interpolation…", "keys.interpolation", json!({})),
             ("Keyframe Velocity…", "keys.velocity", json!({})),
             ("Toggle Hold Keyframe", "keys.toggleHold", json!({})),
+            (if k.muted { "Unmute Keyframes" } else { "Mute Keyframes" }, "keys.setMuted", json!({"muted": !k.muted})),
             ("Rove Across Time", "keys.interpolation", json!({"roving": !k.roving})),
             ("-", "", json!({})),
             ("Easy Ease", "keys.easyEase", json!({})),
@@ -4203,6 +4204,8 @@ fn key_paint(g: &Rw, rc: &RowCtx<'_>, k: &effectcraft_engine::keyframe::Keyframe
         None if ks => t.keyframe_selected,
         None => t.keyframe,
     };
+    // Muted keys stay visible and editable but no longer drive the value.
+    let kcol = if k.muted { kcol.gamma_multiply(0.35) } else { kcol };
     if k.roving {
         // Roving keys: a small dot (their time follows their neighbours).
         gp.circle_filled(c, 2.5, kcol);

crates/ui-egui/src/panels/viewer_overlays.rs

@@ -360,31 +360,36 @@ pub(crate) fn motion_path(
         }
         let v = k.value.as_vec3();
         let s = to_scr(v);
-        // Auto-Bezier keys show handles on a side the path leaves straight too (a two-key path's
-        // ends), to drag it into a curve; Linear keys (no tangents) show none.
-        let (tin, tout) = if k.spatial_auto {
-            effectcraft_engine::keyframe::spatial_handles(&pos.keys, i)
-        } else {
-            effectcraft_engine::keyframe::spatial_tangents(&pos.keys, i)
-        };
-        for (out, tg) in [(false, tin), (true, tout)] {
-            let has = (out && i + 1 < pos.keys.len()) || (!out && i > 0);
-            if !has || (tg[0] == 0.0 && tg[1] == 0.0) {
-                continue;
+        let selected = sel.contains(&KeyRef { layer: l.id, prop: pos.uid, time: k.time });
+        // A muted position key is off the motion path: no tangents, and a dimmed point.
+        let kc = if k.muted { col.gamma_multiply(if selected { 0.55 } else { 0.35 }) } else { col };
+        if !k.muted {
+            // Auto-Bezier keys show handles on a side the path leaves straight too (a two-key path's
+            // ends), to drag it into a curve; Linear keys (no tangents) show none.
+            let (tin, tout) = if k.spatial_auto {
+                effectcraft_engine::keyframe::spatial_handles(&pos.keys, i)
+            } else {
+                effectcraft_engine::keyframe::spatial_tangents(&pos.keys, i)
+            };
+            for (out, tg) in [(false, tin), (true, tout)] {
+                let has = (out && i + 1 < pos.keys.len()) || (!out && i > 0);
+                if !has || (tg[0] == 0.0 && tg[1] == 0.0) {
+                    continue;
+                }
+                let h = to_scr([v[0] + tg[0], v[1] + tg[1], v[2] + tg[2]]);
+                painter.line_segment([s, h], Stroke::new(1.0, kc));
+                painter.circle_filled(h, 3.0, kc);
+                let side = if out { "out" } else { "in" };
+                app.auto.add(&format!("viewer.motionPath.{}.{i}.{side}", l.id.0), Rect::from_center_size(h, vec2(8.0, 8.0)), "Spatial tangent");
+                hits.push(KeyHit { layer: l.id, prop: pos.uid, time: k.time, pos: h, tangent: Some(out), value: v, p2c });
             }
-            let h = to_scr([v[0] + tg[0], v[1] + tg[1], v[2] + tg[2]]);
-            painter.line_segment([s, h], Stroke::new(1.0, col));
-            painter.circle_filled(h, 3.0, col);
-            let side = if out { "out" } else { "in" };
-            app.auto.add(&format!("viewer.motionPath.{}.{i}.{side}", l.id.0), Rect::from_center_size(h, vec2(8.0, 8.0)), "Spatial tangent");
-            hits.push(KeyHit { layer: l.id, prop: pos.uid, time: k.time, pos: h, tangent: Some(out), value: v, p2c });
         }
         let r = Rect::from_center_size(s, vec2(7.0, 7.0));
-        if sel.contains(&KeyRef { layer: l.id, prop: pos.uid, time: k.time }) {
-            painter.rect_filled(r, 0.0, col);
+        if selected {
+            painter.rect_filled(r, 0.0, kc);
         } else {
             painter.rect_filled(r, 0.0, Color32::from_black_alpha(140));
-            painter.rect_stroke(r, 0.0, Stroke::new(1.0, col), StrokeKind::Inside);
+            painter.rect_stroke(r, 0.0, Stroke::new(1.0, kc), StrokeKind::Inside);
         }
         app.auto.add(&format!("viewer.motionPath.{}.{i}", l.id.0), r.expand(2.0), "Position keyframe");
         hits.push(KeyHit { layer: l.id, prop: pos.uid, time: k.time, pos: s, tangent: None, value: v, p2c });