diff --git a/crates/effects/src/sim/tests.rs b/crates/effects/src/sim/tests.rs
index e368c7bbe..d5de4cb74 100644
--- a/crates/effects/src/sim/tests.rs
+++ b/crates/effects/src/sim/tests.rs
@@ -97,6 +97,21 @@ fn bubbles_rise() {
     assert!(y0 >= 0.0 && y1 >= 0.0 && (y1 < y0 || y0 < 8.0), "{y0} -> {y1}");
 }
 
+/// #2024: bubbles near the layer's edges show its edge pixels, not the pale colour that stands
+/// in for transparent ones.
+#[test]
+fn bubbles_near_edges_show_the_layer() {
+    let blue = Image::filled(40, 40, [0.0, 0.0, 1.0, 1.0]);
+    let pale = [0, 1].map(|reflection| {
+        let vals = [("bubbleAmount", num(200.0)), ("bubbleSize", num(3.0)), ("reflectionType", Value::Enum(reflection))];
+        let a = run("ec.sim.ccbubbles", &vals, blue.clone(), 0.3);
+        assert!(a.data.iter().any(|p| p[3] > 0.5), "bubbles drawn");
+        // Blue plus the white highlight keeps blue − red = alpha; the pale colour leaves 0.2 · alpha.
+        a.data.iter().filter(|p| (p[2] - p[0] - p[3]).abs() > 1e-4).count()
+    });
+    assert_eq!(pale, [0, 0], "pale bubble pixels (liquid, metal)");
+}
+
 #[test]
 fn drizzle_ripples() {
     let a = run("ec.sim.ccdrizzle", &[], ramp(48, 48), 0.6);
diff --git a/crates/effects/src/sim/weather.rs b/crates/effects/src/sim/weather.rs
index b93c0e48b..b58b39b5e 100644
--- a/crates/effects/src/sim/weather.rs
+++ b/crates/effects/src/sim/weather.rs
@@ -182,7 +182,7 @@ pub(super) fn bubbles(ctx: &EffectCtx, mut b: Buf) -> Buf {
             // Liquid refracts (inverted, magnified), metal reflects (wide-angle mirror).
             let k = if metal { 1.6 } else { -0.7 };
             let nz = (1.0 - d2).max(0.0).sqrt();
-            let p = src.sample_bilinear((q.sx + dx * q.r * k) as f64, (q.sy + dy * q.r * k) as f64);
+            let p = src.sample_bilinear_clamped((q.sx + dx * q.r * k) as f64, (q.sy + dy * q.r * k) as f64);
             let (c, sa) = unpremul(p);
             let mut c = if sa <= 0.0 { [0.6, 0.7, 0.8] } else { c };
             let mut a = cov;
diff --git a/crates/effects/tests/it/sim_golden.rs b/crates/effects/tests/it/sim_golden.rs
index 2a3a7c724..3932418ad 100644
--- a/crates/effects/tests/it/sim_golden.rs
+++ b/crates/effects/tests/it/sim_golden.rs
@@ -433,26 +433,26 @@ const GOLDEN: &[(&str, u64)] = &[
     ("ec.sim.ccstarburst/1/32bpc/t1.5", 0x5c39f8b1bd0e9e43),
     ("ec.sim.ccstarburst/1/32bpc/t0.8", 0xdf20aa9dcf4b3e22),
     ("ec.sim.ccstarburst/1/32bpc/t2.2", 0x4fa441737bfcb64d),
-    ("ec.sim.ccbubbles/0/8bpc/t0.5", 0xdcd187e75eeb2fae),
-    ("ec.sim.ccbubbles/0/8bpc/t1.5", 0x835ca088747736ed),
-    ("ec.sim.ccbubbles/0/8bpc/t0.8", 0x5cbb1a6fbb77b41d),
-    ("ec.sim.ccbubbles/0/8bpc/t2.2", 0x3b168068f5bfa533),
-    ("ec.sim.ccbubbles/0/32bpc/t0.5", 0x524b84d14edd77e2),
-    ("ec.sim.ccbubbles/0/32bpc/t1.5", 0xfd7a17f0d40f2a27),
-    ("ec.sim.ccbubbles/0/32bpc/t0.8", 0x70dd2b2b4ff0f7ce),
-    ("ec.sim.ccbubbles/0/32bpc/t2.2", 0xae21dd5cc2c2c07c),
+    ("ec.sim.ccbubbles/0/8bpc/t0.5", 0x6cb63df0c062fdf4),
+    ("ec.sim.ccbubbles/0/8bpc/t1.5", 0x5bb1350114234ac3),
+    ("ec.sim.ccbubbles/0/8bpc/t0.8", 0xaa824d49f12c4156),
+    ("ec.sim.ccbubbles/0/8bpc/t2.2", 0x3528577358c4fc90),
+    ("ec.sim.ccbubbles/0/32bpc/t0.5", 0xdcd8e71222c13a9a),
+    ("ec.sim.ccbubbles/0/32bpc/t1.5", 0xd09565e124d8f5db),
+    ("ec.sim.ccbubbles/0/32bpc/t0.8", 0x91242f8e1fd0ad84),
+    ("ec.sim.ccbubbles/0/32bpc/t2.2", 0x1f9782131e62149d),
     ("ec.sim.ccbubbles/0/8bpc/half/t0.5", 0x931b4ca707604220),
     ("ec.sim.ccbubbles/0/8bpc/half/t1.5", 0x21c25d4555abebe9),
     ("ec.sim.ccbubbles/0/8bpc/half/t0.8", 0x7e05972683359632),
     ("ec.sim.ccbubbles/0/8bpc/half/t2.2", 0xadc4f7219dab4921),
-    ("ec.sim.ccbubbles/1/8bpc/t0.5", 0x89d27a2fe2011067),
-    ("ec.sim.ccbubbles/1/8bpc/t1.5", 0x2bbfee897bf5bf6e),
-    ("ec.sim.ccbubbles/1/8bpc/t0.8", 0x26cc704e7b06fffc),
-    ("ec.sim.ccbubbles/1/8bpc/t2.2", 0x959d331545d96479),
-    ("ec.sim.ccbubbles/1/32bpc/t0.5", 0xaf486cebfcbf4641),
-    ("ec.sim.ccbubbles/1/32bpc/t1.5", 0xe150e9fdb558036f),
-    ("ec.sim.ccbubbles/1/32bpc/t0.8", 0x6395f3967cb24284),
-    ("ec.sim.ccbubbles/1/32bpc/t2.2", 0x68a55894d86ffb9e),
+    ("ec.sim.ccbubbles/1/8bpc/t0.5", 0x2f5415c679ff0980),
+    ("ec.sim.ccbubbles/1/8bpc/t1.5", 0xfcfc354dcd22e6d0),
+    ("ec.sim.ccbubbles/1/8bpc/t0.8", 0xdf90fd57c217019c),
+    ("ec.sim.ccbubbles/1/8bpc/t2.2", 0xd365c88c12219802),
+    ("ec.sim.ccbubbles/1/32bpc/t0.5", 0x50f20497f40bb46d),
+    ("ec.sim.ccbubbles/1/32bpc/t1.5", 0x74760599ffba220a),
+    ("ec.sim.ccbubbles/1/32bpc/t0.8", 0x028de52900ed8618),
+    ("ec.sim.ccbubbles/1/32bpc/t2.2", 0xaf0e21d9a7f625fe),
     ("ec.sim.ccdrizzle/0/8bpc/t0.5", 0x2bdfbc17d92b65b5),
     ("ec.sim.ccdrizzle/0/8bpc/t1.5", 0x8c354c46f99e35d3),
     ("ec.sim.ccdrizzle/0/8bpc/t0.8", 0x891f331ba47ee557),
diff --git a/crates/engine/src/cmd/prop.rs b/crates/engine/src/cmd/prop.rs
index ab2f0a1e2..663429fb2 100644
--- a/crates/engine/src/cmd/prop.rs
+++ b/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...",
diff --git a/crates/engine/src/menus.rs b/crates/engine/src/menus.rs
index 9296e1322..a7418ae58 100644
--- a/crates/engine/src/menus.rs
+++ b/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
diff --git a/crates/engine/src/tests/menu_cmds.rs b/crates/engine/src/tests/menu_cmds.rs
index 93f81736f..cfbbb4966 100644
--- a/crates/engine/src/tests/menu_cmds.rs
+++ b/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();
diff --git a/crates/expr/src/prelude.js b/crates/expr/src/prelude.js
index 8fe812590..3196ce5a3 100644
--- a/crates/expr/src/prelude.js
+++ b/crates/expr/src/prelude.js
@@ -31,6 +31,7 @@ function __begin(t, v, c, l, path, uid, idx, fd, ti, tt, sv) {
   __seed = 0;
   __timeless = false;
   __projectInfo = null;
+  __layersTrim();
 }
 
 function __finish(r) {
@@ -44,7 +45,7 @@ function __finish(r) {
 
 function __result(r) {
   r = __v(r);
-  if (r !== null && typeof r === 'object' && r.__isLayer) return r.index;
+  if (typeof r === 'function' && r.__isLayer) return r.index;
   if (r !== null && typeof r === 'object' && r.__isTextStyle) return r.__out();
   // `[temp, temp]` where temp is a property (pick-whip 1D → 2D): read the values here, while
   // host requests can still be answered and the script re-run.
@@ -488,7 +489,7 @@ function __ancestor(c, l, path, countUp) {
   if (typeof n !== 'number' || !(n >= 1) || !isFinite(n)) __err('propertyGroup(' + countUp + '): the count must be a number of 1 or more');
   n = Math.floor(n);
   var info = __h(__ANCESTOR, c, l, path, n);
-  if (info === 'layer') return new Layer(c, l);
+  if (info === 'layer') return __layer(c, l);
   if (info === null) __err('propertyGroup(' + n + ') goes above the layer');
   return __mkGroup(c, l, info);
 }
@@ -518,10 +519,10 @@ Comp.prototype = {
     return __err('Composition "' + this.name + '" has no active camera');
   },
   layer: function (a, rel) {
-    if (a !== null && typeof a === 'object' && a.__isLayer) return this.layer(a.index + (rel || 0));
+    if (typeof a === 'function' && a.__isLayer) return this.layer(a.index + (rel || 0));
     var id = __h(__LAYER, this.__c, a);
     if (id === null) __err(typeof a === 'string' ? 'Layer named "' + a + '" does not exist' : 'Layer index ' + a + ' out of range');
-    return new Layer(this.__c, id);
+    return __layer(this.__c, id);
   },
   toString: function () { return '[object Comp]'; },
 };
@@ -596,7 +597,55 @@ var thisProject = {
 
 // Layer -----------------------------------------------------------------------------------------
 
-function Layer(c, l) { this.__c = c; this.__l = l; this.__i = null; }
+// A layer is a property group too, as in After Effects: `thisLayer("transform")`, another layer's
+// `("effects")("Slider Control")`, `thisLayer(1)` (what the pick whip writes with Compact English
+// off). Callable like a group (`__mkGroup`), with the Layer methods.
+function Layer(c, l) {
+  var f = function (k) { return f.__group(k); };
+  delete f.name;
+  delete f.length;
+  Object.setPrototypeOf(f, Layer.prototype);
+  // Kept across evaluations (`__layer`), so an expression can't change which layer it is, delete
+  // a field or leave its own on it. Its info is private to `__info`, which reads it again in an
+  // evaluation whose `__S` isn't the one it was read in (every evaluation has a new `__S`), so
+  // freezing the layer can't keep its info either.
+  var info = null, read = null;
+  Object.defineProperty(f, '__c', { value: c });
+  Object.defineProperty(f, '__l', { value: l });
+  Object.defineProperty(f, '__info', {
+    get: function () {
+      if (read !== __S) { info = __h(__LINFO, c, l); read = __S; }
+      return info;
+    },
+  });
+  Object.preventExtensions(f);
+  return f;
+}
+
+// Layer `l` of comp `c`, made once per runtime: a callable Layer is dearer to make than a plain
+// object, so it is kept, and its info (`__info`) is read again in each evaluation.
+// The kept layers are out of an expression's reach (their maps have no prototype, so a change to
+// `Object.prototype` doesn't reach them either), and bounded like the runtime's scripts: once
+// `max` are kept, the layers after them aren't, and the next evaluation starts over
+// (`__layersTrim`, so a layer stays the same object for a whole evaluation).
+var __layer, __layersTrim;
+(function () {
+  var layers = Object.create(null), kept = 0, max = 4096;
+  __layer = function (c, l) {
+    // By comp, then layer: a `c + ':' + l` key costs more to build than the lookup saves.
+    var m = layers[c], f = m && m[l];
+    if (f) return f;
+    f = new Layer(c, l);
+    if (kept < max) {
+      (m || (layers[c] = Object.create(null)))[l] = f;
+      kept++;
+    }
+    return f;
+  };
+  __layersTrim = function () {
+    if (kept >= max) { layers = Object.create(null); kept = 0; }
+  };
+})();
 
 function __m3(m, p) {
   var x = p[0] || 0, y = p[1] || 0;
@@ -620,7 +669,6 @@ function __m4(m, p, vec) {
 
 Layer.prototype = {
   __isLayer: true,
-  get __info() { return this.__i || (this.__i = __h(__LINFO, this.__c, this.__l)); },
   get name() { return this.__info[0]; },
   get index() { return this.__info[1]; },
   get inPoint() { return this.__info[2]; },
@@ -632,7 +680,7 @@ Layer.prototype = {
   get parent() {
     var p = this.__info[7];
     if (p === null) __err('Layer "' + this.name + '" has no parent');
-    return new Layer(this.__c, p);
+    return __layer(this.__c, p);
   },
   get hasVideo() { return this.__info[8]; },
   get enabled() { return this.__info[11]; },
@@ -804,7 +852,7 @@ Prop.prototype = {
   propertyGroup: function (n) { return __ancestor(this.__c, this.__l, this.__p, n); },
   __wrap: function (v) {
     var kind = this.__info[2];
-    if (kind === 'layer') return v === null ? null : new Layer(this.__c, v);
+    if (kind === 'layer') return v === null ? null : __layer(this.__c, v);
     if (kind === 'path' && v !== null) return new __Path(v[0], v[1], v[2], v[3]);
     return v;
   },
@@ -834,7 +882,7 @@ Prop.prototype = {
     for (var i = 1; i < times.length; i++) if (Math.abs(times[i] - t) < Math.abs(times[best] - t)) best = i;
     return this.key(best + 1);
   },
-  __seedIndex: function () { return this.__self ? __S.idx : new Layer(this.__c, this.__l).index; },
+  __seedIndex: function () { return this.__self ? __S.idx : __layer(this.__c, this.__l).index; },
   wiggle: function (freq, amp, octaves, ampMult, t) {
     if (octaves === undefined) octaves = 1;
     if (ampMult === undefined) ampMult = 0.5;
@@ -903,8 +951,9 @@ var __propHandler = {
     var v = t.value;
     if (v === null || v === undefined) return undefined;
     var x = v[k];
-    // Property groups are callable proxies: hand them over as they are, not bound like methods (#809).
-    if (x?.__isGroup) return x;
+    // Property groups and layers are callable: hand them over as they are, not bound like methods
+    // (#809).
+    if (typeof x === 'function' && (x.__isGroup || x.__isLayer)) return x;
     return typeof x === 'function' ? x.bind(v) : x;
   },
 };
@@ -1082,18 +1131,18 @@ Markers.prototype = {
 // ---------------------------------------------------------------------------------------------
 // Unqualified names: thisLayer / thisProperty attributes and the `this*` objects. They're
 // accessors on the global object; assigning one (`var width = 10`) shadows it for the current
-// evaluation only.
+// evaluation only. They can't be deleted or redefined, so an expression can't take one away from
+// the evaluations after it.
 
 function __global(name, get) {
   Object.defineProperty(globalThis, name, {
-    configurable: true,
     get: function () { return name in __S.vars ? __S.vars[name] : get(); },
     set: function (v) { __S.vars[name] = v; },
   });
 }
 
 __global('thisComp', function () { return __S.comp || (__S.comp = new Comp(__S.c)); });
-__global('thisLayer', function () { return __S.layer || (__S.layer = new Layer(__S.c, __S.l)); });
+__global('thisLayer', function () { return __S.layer || (__S.layer = __layer(__S.c, __S.l)); });
 __global('thisProperty', function () { return __S.prop || (__S.prop = __mkProp(__S.c, __S.l, __S.path)); });
 ['name', 'index', 'inPoint', 'outPoint', 'startTime', 'width', 'height', 'hasParent', 'parent', 'hasVideo', 'enabled', 'active',
   'transform', 'position', 'scale', 'rotation', 'opacity', 'anchorPoint', 'text', 'marker'].forEach(function (k) {
@@ -1226,3 +1275,23 @@ function nearestKey(t) { return thisProperty.nearestKey(t); }
   delete globalThis.Proxy;
   delete globalThis.Reflect;
 })();
+
+// ---------------------------------------------------------------------------------------------
+// The runtime runs this file once and keeps it for the thread's later evaluations, so an
+// expression can't change the object model or the internals: the prototypes are frozen, and the
+// `__` globals, the constructors and `thisProject` can't be reassigned. The `__` state below is
+// set again by `__begin` in each evaluation.
+
+[Comp, Footage, Layer, Prop, Markers, __Path, __TextStyle].forEach(function (f) {
+  Object.freeze(f.prototype);
+  Object.freeze(f);
+});
+[__GroupProto, __groupHandler, __propHandler, thisProject].forEach(Object.freeze);
+(function () {
+  var perEvaluation = { __S: true, __rc: true, __seed: true, __timeless: true, __projectInfo: true };
+  var model = { Comp: true, Footage: true, Layer: true, Prop: true, Markers: true, thisProject: true };
+  Object.getOwnPropertyNames(globalThis).forEach(function (k) {
+    if (!(k.slice(0, 2) === '__' && !perEvaluation[k]) && !model[k]) return;
+    if ('value' in Object.getOwnPropertyDescriptor(globalThis, k)) Object.defineProperty(globalThis, k, { writable: false, configurable: false });
+  });
+})();
diff --git a/crates/expr/src/tests.rs b/crates/expr/src/tests.rs
index 55720a327..a9ec582c5 100644
--- a/crates/expr/src/tests.rs
+++ b/crates/expr/src/tests.rs
@@ -1099,6 +1099,8 @@ fn shadowing_layer_attribute_names_is_local() {
     let f = fx();
     assert_close!(f.num("var width = 3;\nwidth * 2", 0.0), 6.0);
     assert_close!(f.num("width", 0.0), 20.0, 1e-9);
+    assert_close!(f.num("function width() { return 4; }\nwidth() * 2", 0.0), 8.0);
+    assert_close!(f.num("width", 0.0), 20.0, 1e-9);
 }
 
 #[test]
@@ -1493,4 +1495,97 @@ fn time_to_frames_preserves_coercion_and_small_durations() {
     }
 }
 
+/// A layer is a property group too, as in After Effects: `thisLayer("transform")`, another
+/// layer's `("effects")("Slider Control")` or `(1)`, as the pick whip writes them with Compact
+/// English off (they failed: "not a callable function"). It is still a layer.
+#[test]
+fn layers_are_callable_property_groups() {
+    let f = fx();
+    assert_close!(f.num("thisLayer(\"transform\")(\"opacity\")", 0.0), 100.0);
+    assert_close!(f.num("thisComp.layer(\"A\")(\"effects\")(\"ec.control.slider\")(\"slider\")", 0.0), 42.0);
+    assert_close!(f.num("thisComp.layer(\"A\")(\"effects\")(\"Slider Control\")(1)", 0.0), 42.0);
+    assert_close!(f.num("thisComp.layer(1)(\"effects\")(1)(1)", 0.0), 42.0);
+    // Its own name, index and methods, and a layer as the result still reads as its index.
+    assert_close!(f.num("thisLayer.name == \"A\" ? thisComp.layer(\"B\").index : 0", 0.0), 2.0);
+    assert_close!(f.num("thisComp.layer(\"B\")", 0.0), 2.0);
+    assert_close!(f.num("thisComp.layer(thisComp.layer(\"B\"), -1).index", 0.0), 1.0);
+    assert!(f.err("thisLayer(\"nope\")").contains("no property"), "{}", f.err("thisLayer(\"nope\")"));
+}
+
+/// A layer is kept from one evaluation to the next (it is dear to make) but reads the project
+/// afresh in each, and an expression's own fields on it don't reach the next one.
+#[test]
+fn a_kept_layer_reads_the_project_again() {
+    let mut f = fx();
+    let first = "thisComp.layer(\"B\").index * 10 + thisComp.layer(2).name.length";
+    assert_close!(f.num(first, 0.0), 21.0);
+    f.layer_mut(f.b).name = "Bee".into();
+    f.p.comp_mut(f.cid).unwrap().layers.swap(0, 1);
+    assert_close!(f.num("thisComp.layer(\"Bee\").index * 10 + thisComp.layer(2).name.length", 0.0), 11.0);
+    assert_close!(f.num("thisLayer.index", 0.0), 2.0);
+    let _ = f.ev(f.a, ROT, "thisLayer.mine = 5; 0", 0.0);
+    assert_close!(f.num("thisLayer.mine === undefined ? 1 : 0", 0.0), 1.0);
+    let _ = f.ev(f.a, ROT, "var L = thisLayer; L.__c = 'x'; L.__l = 99; L.__i = ['Z', 7]; L.__s = __S; 0", 0.0);
+    assert_close!(f.num("thisLayer.index * 10 + thisLayer.name.length", 0.0), 21.0);
+    let _ = f.ev(f.a, ROT, "var L = thisLayer; delete L.__c; delete L.__l; delete L.__i; delete L.__s; 0", 0.0);
+    assert_close!(f.num("thisLayer.index * 10 + thisLayer.name.length", 0.0), 21.0);
+    let _ = f.ev(f.a, ROT, "Object.freeze(thisLayer); 0", 0.0);
+    f.layer_mut(f.a).name = "Ay".into();
+    f.p.comp_mut(f.cid).unwrap().layers.swap(0, 1);
+    assert_close!(f.num("thisLayer.index * 10 + thisLayer.name.length", 0.0), 12.0);
+}
+
+/// The kept layers are bounded: past the bound a layer isn't kept, an evaluation that makes more
+/// layers than are kept still sees one object for each layer it had kept, and the evaluations
+/// after it, which start over, read the right layers.
+#[test]
+fn the_kept_layers_are_bounded() {
+    let f = fx();
+    let same = "(thisLayer === thisComp.layer(thisLayer.index) ? 1 : 0)";
+    let many =
+        format!("var c = thisLayer.__c;\nfor (var i = 0; i < 5000; i++) __layer(c, 100000 + i);\n{same} * 10 + (__layer(c, 1e6) === __layer(c, 1e6) ? 0 : 1)");
+    assert_close!(f.num(&many, 0.0), 11.0);
+    assert_close!(f.num(&format!("{same} * 100 + thisLayer.index * 10 + thisLayer.name.length"), 0.0), 111.0);
+    assert_close!(f.num(&format!("{same} * 100 + thisLayer.index * 10 + thisLayer.name.length"), 0.0), 111.0);
+}
+
+/// A change to `Object.prototype` doesn't reach the kept layers: a frozen object put there under
+/// the comp's id, before any of its layers is kept, doesn't stop them being kept.
+#[test]
+fn the_kept_layers_dont_go_through_object_prototype() {
+    let f = fx();
+    let _ = f.ev(f.a, ROT, "try { Object.prototype[thisComp.__c] = Object.freeze({}); } catch (e) {} 0", 0.0);
+    assert_close!(f.num("thisLayer === thisComp.layer(thisLayer.index) ? 1 : 0", 0.0), 1.0);
+}
+
+/// The prelude is kept from one evaluation to the next, so an expression can't change its object
+/// model or internals for the ones after it.
+#[test]
+fn an_expression_cant_change_the_prelude_for_the_next() {
+    let f = fx();
+    let read = "[thisComp.layer(1).index, thisLayer.index, thisLayer('transform').property('rotation').value,                 thisLayer.transform.opacity.value, thisProject.bitsPerChannel, comp(thisComp.name).numLayers, width]";
+    let before = f.ev(f.a, ROT, read, 0.5).unwrap();
+    let attacks = [
+        "Comp.prototype.layer = function () { return 0; }",
+        "Object.getPrototypeOf(thisLayer).index = 0",
+        "Object.getPrototypeOf(thisLayer('transform')).property = function () { return 0; }",
+        "Object.getPrototypeOf(thisLayer.transform.opacity).value = 0",
+        "Comp = function () {}",
+        "Prop = function () {}",
+        "thisProject = null",
+        "__h = function () { return null; }",
+        "__layer = function () { return null; }",
+        "__child = function () {}",
+        "delete __mkProp",
+        "delete thisLayer",
+        "delete thisComp",
+        "delete width",
+        "Object.defineProperty(globalThis, 'thisComp', { get: function () { return 0; } })",
+    ];
+    for a in attacks {
+        let _ = f.ev(f.a, ROT, &format!("try {{ {a} }} catch (e) {{}} 0"), 0.0);
+        assert_eq!(f.ev(f.a, ROT, read, 0.5).unwrap(), before, "after `{a}`");
+    }
+}
+
 mod property_group;
diff --git a/crates/expr/src/tests/property_group.rs b/crates/expr/src/tests/property_group.rs
index debe5e5ac..c96045ec2 100644
--- a/crates/expr/src/tests/property_group.rs
+++ b/crates/expr/src/tests/property_group.rs
@@ -72,6 +72,9 @@ fn property_group_reaches_the_layer() {
     assert_close!(f.num("thisProperty.propertyGroup(2).name == 'A' ? 1 : 0", 0.0), 1.0);
     assert_close!(f.num("thisProperty.propertyGroup(2).index", 0.0), 1.0);
     assert_close!(f.num("thisProperty.propertyGroup(1).propertyGroup(1).name == 'A' ? 1 : 0", 0.0), 1.0);
+    // The layer it reaches is the same object as `thisLayer`.
+    assert_close!(f.num("thisLayer('transform').propertyGroup(1) === thisLayer ? 1 : 0", 0.0), 1.0);
+    assert_close!(f.num("thisProperty.propertyGroup(2) === thisLayer ? 1 : 0", 0.0), 1.0);
     let s = staggered();
     assert_close!(s.shape_num(SCALE_2, "thisProperty.propertyGroup(4).name == 'Shape' ? 1 : 0"), 1.0);
 }
diff --git a/crates/gpu/src/shaders/fx_sim.wgsl b/crates/gpu/src/shaders/fx_sim.wgsl
index d936861d3..8ef3035fe 100644
--- a/crates/gpu/src/shaders/fx_sim.wgsl
+++ b/crates/gpu/src/shaders/fx_sim.wgsl
@@ -180,7 +180,7 @@ fn fxm_bubble(at: u32, x: f32, y: f32) -> FxmShade {
     }
     let k = select(-0.7, 1.6, P.u[1].y != 0u);
     let nz = sqrt(max(1.0 - d2, 0.0));
-    let s = fxm_unpremul(sample_bilinear(src, data[at + 4u] + dx * qr * k, data[at + 5u] + dy * qr * k));
+    let s = fxm_unpremul(sample_bilinear_clamped(src, data[at + 4u] + dx * qr * k, data[at + 5u] + dy * qr * k));
     var c = s.xyz;
     if (s.w <= 0.0) {
         c = vec3<f32>(0.6, 0.7, 0.8);
diff --git a/crates/interchange/src/export.rs b/crates/interchange/src/export.rs
index 7da18913a..cc44475f3 100644
--- a/crates/interchange/src/export.rs
+++ b/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,
diff --git a/crates/interchange/src/tests.rs b/crates/interchange/src/tests.rs
index 1e0c7d417..2fe36d47b 100644
--- a/crates/interchange/src/tests.rs
+++ b/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();
diff --git a/crates/keyframe/src/lib.rs b/crates/keyframe/src/lib.rs
index f0dd4849c..abf929fe9 100644
--- a/crates/keyframe/src/lib.rs
+++ b/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
         }
diff --git a/crates/keyframe/src/tests.rs b/crates/keyframe/src/tests.rs
index 0a31cfc19..312703239 100644
--- a/crates/keyframe/src/tests.rs
+++ b/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));
+}
diff --git a/crates/lottie/src/anim.rs b/crates/lottie/src/anim.rs
index e3264e3b7..4925460a9 100644
--- a/crates/lottie/src/anim.rs
+++ b/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;
diff --git a/crates/lottie/src/tests.rs b/crates/lottie/src/tests.rs
index 31f3a70bb..203f04c04 100644
--- a/crates/lottie/src/tests.rs
+++ b/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);
+}
diff --git a/crates/media/src/probe.rs b/crates/media/src/probe.rs
index f695ff0d0..41b50b0f4 100644
--- a/crates/media/src/probe.rs
+++ b/crates/media/src/probe.rs
@@ -23,6 +23,7 @@ pub fn probe(path: impl AsRef<Path>) -> Result<Footage> {
         let turn = header.as_deref().map_or(Orientation::NoTransforms, video_turn);
         turn_footage(&mut f, turn);
         correct_rate(&mut f, header.as_deref().and_then(video_rate));
+        trim_to_edits(&mut f, header.as_deref().and_then(video_shown));
         return Ok(f);
     }
     let bytes = crate::read_regular_file(path).map_err(|e| MediaError::Io(format!("{}: {e}", path.display())))?;
@@ -107,6 +108,7 @@ pub fn probe_bytes(path: &str, bytes: Arc<[u8]>) -> Result<Footage> {
     let name = Path::new(path).file_name().map(|n| n.to_string_lossy().to_string()).unwrap_or_else(|| path.to_string());
     let turn = video_turn(&bytes);
     let rate = video_rate(&bytes);
+    let shown = video_shown(&bytes);
     // A WAV's cue points and XMP markers become the footage's markers.
     let markers = crate::wav_markers::read(&bytes);
     let src = filmcraft_codecs::open_bytes(&name, bytes)?;
@@ -114,9 +116,37 @@ pub fn probe_bytes(path: &str, bytes: Arc<[u8]>) -> Result<Footage> {
     f.markers = markers;
     turn_footage(&mut f, turn);
     correct_rate(&mut f, rate);
+    trim_to_edits(&mut f, shown);
     Ok(f)
 }
 
+/// A movie lasts as long as its video edit list shows (#2592): the reader reports the media
+/// duration (`mdhd`), which for H.264 with B-frames runs past the last shown frame by the
+/// encoder delay the edit list trims (75 frames at 25 fps read as 3.04 s). Never lengthens.
+fn trim_to_edits(f: &mut Footage, shown: Option<Tick>) {
+    if f.kind == FootageKind::Video
+        && let Some(shown) = shown.filter(|s| *s > Tick::ZERO && *s < f.duration)
+    {
+        f.duration = shown;
+    }
+}
+
+/// How long the video track's edit list shows its media (`elst` segments, movie timescale):
+/// `None` without edits, or with an empty edit (a delayed start keeps the reader's duration).
+fn video_shown(bytes: &[u8]) -> Option<Tick> {
+    let file = filmcraft_isobmff::open(bytes).ok()?;
+    let t = file.tracks.iter().find(|t| t.kind == filmcraft_isobmff::TrackKind::Video && !t.samples.is_empty())?;
+    edits_shown(&t.edits, file.timescale)
+}
+
+fn edits_shown(edits: &[filmcraft_isobmff::Edit], timescale: u32) -> Option<Tick> {
+    if edits.is_empty() || timescale == 0 || edits.iter().any(|e| e.media_time < 0) {
+        return None;
+    }
+    let units = edits.iter().try_fold(0u64, |acc, e| acc.checked_add(e.segment_duration))?;
+    Some(Tick::from_units(i64::try_from(units).ok()?, i64::from(timescale)))
+}
+
 /// A movie's frame rate as its frame durations average to ([`video_rate`]), where the reader's
 /// own estimate misreads it.
 fn correct_rate(f: &mut Footage, rate: Option<FrameRate>) {
@@ -322,6 +352,24 @@ fn averaged_rate(timescale: u32, durations: impl Iterator<Item = u32>) -> Option
 mod tests {
     use super::*;
 
+    /// #2592: an encoder-delayed H.264 track's edit list shows 75 frames at 25 fps (3 s at a
+    /// 1000 timescale), though its media runs a frame longer; empty edits and no edits leave it.
+    #[test]
+    fn the_edit_list_trims_a_movie_to_the_frames_it_shows() {
+        let edit = |segment_duration, media_time| filmcraft_isobmff::Edit { segment_duration, media_time, media_rate: 0x0001_0000 };
+        let shown = edits_shown(&[edit(3000, 1024)], 1000);
+        assert_eq!(shown, Some(Tick::from_units(3, 1)));
+        let mut f = Footage { kind: FootageKind::Video, duration: Tick::from_units(76, 25), ..Footage::default() };
+        trim_to_edits(&mut f, shown);
+        assert_eq!(f.duration, Tick::from_units(75, 25));
+        // Never longer than the reader's duration, and only for video.
+        trim_to_edits(&mut f, Some(Tick::from_units(4, 1)));
+        assert_eq!(f.duration, Tick::from_units(75, 25));
+        assert_eq!(edits_shown(&[edit(1000, -1), edit(3000, 0)], 1000), None);
+        assert_eq!(edits_shown(&[], 1000), None);
+        assert_eq!(edits_shown(&[edit(3000, 0)], 0), None);
+    }
+
     /// Durations (in 1/`timescale` s) of `n` frames at `rate` whose times are rounded to the timescale.
     fn rounded(rate: FrameRate, timescale: i64, n: i64) -> Vec<u32> {
         let at = |k: i64| (2 * k * timescale * rate.den + rate.num) / (2 * rate.num);
diff --git a/crates/script/src/prelude.js b/crates/script/src/prelude.js
index a33714314..b9108b2a1 100644
--- a/crates/script/src/prelude.js
+++ b/crates/script/src/prelude.js
@@ -1706,7 +1706,8 @@ Object.defineProperty(FootageItem.prototype, "mainSource", {
     return this.__mainSource;
   },
 });
-FootageItem.prototype.replace = function (f) { __call("file.replaceFootage", { item: this.__id, path: __str(f) }); };
+// replace() swaps in one file, even a numbered still (replaceWithSequence brings a run), as in After Effects.
+FootageItem.prototype.replace = function (f) { __call("file.replaceFootage", { item: this.__id, path: __str(f), sequence: false }); };
 FootageItem.prototype.replaceWithSequence = function (f, forceAlphabetical) {
   __call("file.replaceFootage", { item: this.__id, path: __str(f), sequence: true, alphabetical: !!forceAlphabetical });
 };
diff --git a/crates/script/src/tests.rs b/crates/script/src/tests.rs
index 875885c11..3f8190a73 100644
--- a/crates/script/src/tests.rs
+++ b/crates/script/src/tests.rs
@@ -1062,6 +1062,11 @@ fn footage_proxies_sequences_and_conform_rate() {
     let paths: Vec<String> =
         s.project.items.values().filter_map(|i| if let ItemKind::Footage(f) = &i.kind { Some(f.path.replace('\\', "/")) } else { None }).collect();
     assert!(paths.iter().any(|f| f.contains("take_")), "replaced with the take sequence: {paths:?}");
+    // replace() swaps in the one file, even a numbered still, as in After Effects.
+    ok(&mut s, &format!("app.project.item(1).replace(new File('{}'))", p("shot_0002.png")));
+    let kinds: Vec<_> =
+        s.project.items.values().filter_map(|i| if let ItemKind::Footage(f) = &i.kind { Some((f.kind, f.path.replace('\\', "/"))) } else { None }).collect();
+    assert!(kinds.iter().any(|(k, f)| *k == effectcraft_engine::project::FootageKind::Still && f.ends_with("shot_0002.png")), "{kinds:?}");
     let _ = std::fs::remove_dir_all(&dir);
 }
 
diff --git a/crates/ui-egui/src/i18n.rs b/crates/ui-egui/src/i18n.rs
index 254eec49c..6da705ef1 100644
--- a/crates/ui-egui/src/i18n.rs
+++ b/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"),
diff --git a/crates/ui-egui/src/panels/graph.rs b/crates/ui-egui/src/panels/graph.rs
index 24df22616..51b288cc6 100644
--- a/crates/ui-egui/src/panels/graph.rs
+++ b/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);
diff --git a/crates/ui-egui/src/panels/render_queue.rs b/crates/ui-egui/src/panels/render_queue.rs
index 5e39a30c2..c7cce6e01 100644
--- a/crates/ui-egui/src/panels/render_queue.rs
+++ b/crates/ui-egui/src/panels/render_queue.rs
@@ -451,6 +451,22 @@ fn queue_drop(app: &EffectcraftApp, ui: &egui::Ui, rect: Rect, p: &egui::Painter
     }
 }
 
+/// Elapsed and estimated remaining seconds at UI time `now`. The job reports them as frames
+/// finish; between reports they count on from the last one, as a clock does, so a slow frame
+/// doesn't read as a stalled render (#2593).
+fn live_times(ctx: &egui::Context, pr: &effectcraft_engine::render_queue::JobState, now: f64) -> (f64, Option<f64>) {
+    let report = (pr.current, pr.done, pr.item_elapsed.to_bits());
+    let since = ctx.data_mut(|d| {
+        let seen = d.get_temp_mut_or_insert_with(egui::Id::unique("rq-progress-seen"), || (report, now));
+        if seen.0 != report {
+            *seen = (report, now);
+        }
+        seen.1
+    });
+    let dt = if pr.finished { 0.0 } else { (now - since).max(0.0) };
+    (pr.item_elapsed + dt, pr.remaining.map(|r| (r - dt).max(0.0)))
+}
+
 /// The Current Render strip inside `top`: title, elapsed / remaining time, Render, Stop, Notify
 /// and the progress bar.
 fn current_render_strip(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::Painter, top: Rect, rq: &RqView, actions: &mut Vec<Action>) {
@@ -461,11 +477,15 @@ fn current_render_strip(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: &egui::P
     let cur_item = progress.as_ref().and_then(|p| p.current).and_then(|id| queue.iter().find(|i| i.id == id));
     let cur_name = cur_item.and_then(|i| app.session.project.item(i.comp)).map(|i| i.name.clone());
     if let Some(pr) = &progress {
-        let rem = pr.remaining.map(hms).unwrap_or_else(|| "–".into());
+        let (elapsed, remaining) = live_times(ui.ctx(), pr, ui.input(|i| i.time));
+        if rendering {
+            ui.ctx().request_repaint_after(std::time::Duration::from_millis(500));
+        }
+        let rem = remaining.map(hms).unwrap_or_else(|| "–".into());
         p.text(
             pos2(top.max.x - 12.0, top.min.y + 16.0),
             Align2::RIGHT_CENTER,
-            format!("Elapsed: {}     Est. Remain: {rem}", hms(pr.item_elapsed)),
+            format!("Elapsed: {}     Est. Remain: {rem}", hms(elapsed)),
             Tokens::ui(11.5),
             t.text_dim,
         );
@@ -903,4 +923,26 @@ mod tests {
         assert_eq!(super::utc_stamp(u64::MAX), "584554051223-11-09 07:00:15");
         assert_eq!(super::hms(3725.4), "1:02:05");
     }
+
+    /// #2593: between progress reports the times count on from the last report, and a new
+    /// report starts the count again.
+    #[test]
+    fn render_times_tick_between_reports() {
+        let ctx = egui::Context::default();
+        let mut pr = effectcraft_engine::render_queue::JobState {
+            current: Some(1),
+            done: 2,
+            total: 10,
+            item_elapsed: 20.0,
+            remaining: Some(80.0),
+            ..Default::default()
+        };
+        assert_eq!(super::live_times(&ctx, &pr, 100.0), (20.0, Some(80.0)));
+        assert_eq!(super::live_times(&ctx, &pr, 103.0), (23.0, Some(77.0)));
+        assert_eq!(super::live_times(&ctx, &pr, 300.0).1, Some(0.0), "never below zero");
+        (pr.done, pr.item_elapsed, pr.remaining) = (3, 31.0, Some(72.0));
+        assert_eq!(super::live_times(&ctx, &pr, 301.0), (31.0, Some(72.0)));
+        pr.finished = true;
+        assert_eq!(super::live_times(&ctx, &pr, 400.0), (31.0, Some(72.0)), "a finished job stands still");
+    }
 }
diff --git a/crates/ui-egui/src/panels/timeline.rs b/crates/ui-egui/src/panels/timeline.rs
index 98bc4d8d2..81e39ccaf 100644
--- a/crates/ui-egui/src/panels/timeline.rs
+++ b/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);
diff --git a/crates/ui-egui/src/panels/viewer_overlays.rs b/crates/ui-egui/src/panels/viewer_overlays.rs
index ef4549db6..05884abce 100644
--- a/crates/ui-egui/src/panels/viewer_overlays.rs
+++ b/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 });