Keyframes: mute keyframes without deleting them (#1894)

Add a muted flag to Keyframe. Muted keys stay in the Timeline and Graph Editor (dimmed, selectable and movable) but evaluation skips them, so the active neighbours interpolate as if they were not there; auto-Bezier and eases use the active neighbours. When every key is muted the property falls back to its static value.\n\nkeys.setMuted {muted} mutes or unmutes the selected keys in one undo step. The Timeline context menu offers Mute/Unmute Keyframes and the Animation menu has Mute Keyframes. Muted keys have no Bezier handles and motion-path points are dimmed.\n\nLottie export omits muted keys (with a warning) because Lottie has no mute state; scripting keeps seeing them in numKeys/key().\n\nTests: keyframe evaluation (linear, auto-Bezier spatial, all muted), serialization and value replacement, engine command + undo, Lottie export.

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();