From 3058b9a5f292e34cee300a16079336a19168abce Mon Sep 17 00:00:00 2001
From: Olive Vaughn <olivevaughncode@gmail.com>
Date: Mon, 28 Sep 2026 16:31:27 -0400
Subject: [PATCH] Add scoped feature regeneration and retained pixel
 measurements

---
 clips/templates/clips/index.html              |  13 ++
 frontend/src/arthur/demo/stage.cljs           |  14 +-
 frontend/src/arthur/domain/feature.cljs       |   5 +-
 frontend/src/arthur/events/footage.cljs       |  51 ++++---
 frontend/src/arthur/events/project.cljs       | 140 ++++++++++++++++-
 frontend/src/arthur/flow/address.cljs         |   2 +
 frontend/src/arthur/flow/freeze.cljs          | 141 ++++++++++++------
 frontend/src/arthur/flow/regenerate.cljs      | 125 ++++++++++++++++
 frontend/src/arthur/flow/source.cljs          |  84 +++++++++--
 frontend/src/arthur/flow/take.cljs            |  38 +++++
 frontend/src/arthur/footage/store.cljs        |   3 +-
 frontend/src/arthur/ui/shell.cljs             |  91 ++++++++++-
 .../test/arthur/flow/regenerate_test.cljs     | 101 +++++++++++++
 frontend/test/arthur/flow/source_test.cljs    |  27 ++++
 frontend/test/browser/take.mjs                | 135 ++++++++++++++++-
 15 files changed, 889 insertions(+), 81 deletions(-)
 create mode 100644 frontend/src/arthur/flow/regenerate.cljs
 create mode 100644 frontend/test/arthur/flow/regenerate_test.cljs

diff --git a/clips/templates/clips/index.html b/clips/templates/clips/index.html
index 2a75220..6de64b3 100644
--- a/clips/templates/clips/index.html
+++ b/clips/templates/clips/index.html
@@ -48,6 +48,19 @@ and PUTs with ordinary CSRF protection — no endpoint in this app is exempt.
                             color: var(--fg); background: #1c1f2b; border: 1px solid #2b3040;
                             font: inherit; max-width: 360px; }
       .load-status { margin-top: 6px; font-size: 12px; opacity: .75; }
+      .controls { width: 640px; margin-top: 18px; padding-top: 12px;
+                  border-top: 1px solid #2b3040; font-size: 12px; }
+      .controls select { margin-left: 8px; padding: 3px 5px; color: var(--fg);
+                         background: #1c1f2b; border: 1px solid #2b3040; font: inherit; }
+      .shared-note { margin-top: 6px; color: #d0ba86; }
+      .control-list { display: grid; grid-template-columns: 1fr 1fr; gap: 6px 16px;
+                      margin-top: 10px; }
+      .control-row { display: grid; grid-template-columns: 115px 1fr 42px;
+                     align-items: center; gap: 6px; }
+      .control-row input { width: 100%; }
+      .control-row output { text-align: right; }
+      .regeneration-debug { padding: 8px; margin-top: 10px; background: #1c1f2b;
+                            white-space: pre-wrap; color: #d0ba86; }
       .note { opacity: .35; font-size: 12px; max-width: 640px; }
     </style>
   </head>
diff --git a/frontend/src/arthur/demo/stage.cljs b/frontend/src/arthur/demo/stage.cljs
index 16066ad..58bd0a1 100644
--- a/frontend/src/arthur/demo/stage.cljs
+++ b/frontend/src/arthur/demo/stage.cljs
@@ -45,8 +45,12 @@
                                 :channels (cond-> {[:audio :gain] gain}
                                             pan (assoc [:audio :pan] pan))}])
                          audio))]
-    (-> source
-        (assoc :name name :width width :height height
-               :timelines {:main {:id :main :frames frames :nodes nodes}
-                           symbol (assoc original :id symbol)})
-        (dissoc :subjects :features :groups))))
+    (cond-> (assoc source :name name :width width :height height
+                   :timelines {:main {:id :main :frames frames :nodes nodes}
+                               symbol (assoc original :id symbol)})
+      ;; These are the same tracked features in the shared symbol. Every
+      ;; placement reads them; tuning one changes all instances.
+      (seq (:features source))
+      (assoc :features (into {} (map (fn [[id f]]
+                                      [id (assoc f :timeline symbol)]))
+                             (:features source))))))
diff --git a/frontend/src/arthur/domain/feature.cljs b/frontend/src/arthur/domain/feature.cljs
index b56e84f..0a4c97b 100644
--- a/frontend/src/arthur/domain/feature.cljs
+++ b/frontend/src/arthur/domain/feature.cljs
@@ -73,7 +73,10 @@
             :when (not (params/valid-settings? (:area f) (or (:params f) {})))]
         (str "feature " (pr-str id) " has invalid settings for " (pr-str (:area f))))
       (for [[id f] features node-id (:nodes f)
-            :when (not (contains? nodes node-id))]
+            :let [owned-nodes (if-let [timeline (:timeline f)]
+                                (get-in clip [:timelines timeline :nodes])
+                                nodes)]
+            :when (not (contains? owned-nodes node-id))]
         (str "feature " (pr-str id) " refers to missing node " (pr-str node-id)))
       (for [[id n] (frequencies node-owners) :when (> n 1)]
         (str "node " (pr-str id) " belongs to more than one feature"))
diff --git a/frontend/src/arthur/events/footage.cljs b/frontend/src/arthur/events/footage.cljs
index 1e5d8bd..c0f95ad 100644
--- a/frontend/src/arthur/events/footage.cljs
+++ b/frontend/src/arthur/events/footage.cljs
@@ -108,7 +108,8 @@
            :frames (clip/frames built)
            :display-fps (:fps built)
            :clip built :store (:store frozen)
-           :source-blocks source-blocks :source-inputs source-inputs
+           :source-blocks source-blocks
+           :source-inputs (assoc source-inputs :presence (:presence manifest))
            ;; No cache-buster. The audio is a blob named by the hash of its own
            ;; bytes, so re-extracting gives it a different URL rather than
            ;; overwriting this one — which is what the `?v=` here used to work
@@ -124,24 +125,40 @@
                                 (when (pos? first-real)
                                  (str " (first found on " (inc first-real) ")"))))))))
 
-(defn- cached-source! [manifest detector]
-  (let [key (:id (take/analysis-for manifest detector))]
-    (-> (http/GET (str "/api/analyses/" key))
-        (.then (fn [^js analysis]
-                 (let [keys (array-seq (.-source_blocks analysis))]
-                   (when (= (count keys) (count source/roles))
-                     (-> (js/Promise.all
-                          (into-array (map #(http/GET (str "/api/blocks/" %)) keys)))
-                         (.then (fn [blocks]
-                                  (source/unpack blocks
-                                                 [(:width manifest) (:height manifest)]))))))))
+(defn- with-default-interior! [analysis track]
+  (let [frames (count (:crops track))
+        key (source/interior-key analysis take/knobs frames)]
+    (-> (http/GET (str "/api/blocks/" key))
+        (.then (fn [block]
+                 (assoc track :interior (source/unpack-interior block take/knobs frames)
+                        :interior-key key)))
         (.catch (fn [error]
-                  (if (= 404 (:status (ex-data error))) nil (throw error)))))))
+                  (if (= 404 (:status (ex-data error))) track (throw error)))))))
+
+(defn saved-source!
+  "Restore retained source tracks by analysis id, for regeneration after open."
+  [key dimensions]
+  (-> (http/GET (str "/api/analyses/" key))
+      (.then (fn [^js analysis]
+               (let [keys (array-seq (.-source_blocks analysis))]
+                 (when (= (count keys) (count source/roles))
+                   (-> (js/Promise.all
+                        (into-array (map #(http/GET (str "/api/blocks/" %)) keys)))
+                       (.then (fn [blocks] (source/unpack blocks dimensions)))
+                       (.then (fn [track] (with-default-interior! key track))))))))
+      (.catch (fn [error]
+                (if (= 404 (:status (ex-data error))) nil (throw error))))))
+
+(defn- cached-source! [manifest detector]
+  (saved-source! (:id (take/analysis-for manifest detector))
+                 [(:width manifest) (:height manifest)]))
 
 (defn- measure-cached! [track]
-  ;; Cached source blocks hold crop pixels, but no interior measurements. Spread
-  ;; their measurement over event-loop turns just like the fresh decode path.
-  (let [crops (:crops track)
+  ;; Older analyses may lack the optional interior block. Spread their one-time
+  ;; measurement over event-loop turns just like the fresh decode path.
+  (if (:interior track)
+    (js/Promise.resolve track)
+    (let [crops (:crops track)
         total (count crops)
         interior (atom [])]
     (js/Promise.
@@ -156,7 +173,7 @@
                                      (str "measuring " (inc i) "/" total)]))
                      (js/setTimeout #(step (inc i)) 0)
                      (catch :default error (reject error)))))]
-         (step 0))))))
+         (step 0)))))))
 
 (rf/reg-fx
  ::begin!
diff --git a/frontend/src/arthur/events/project.cljs b/frontend/src/arthur/events/project.cljs
index 351eadf..8905c99 100644
--- a/frontend/src/arthur/events/project.cljs
+++ b/frontend/src/arthur/events/project.cljs
@@ -24,13 +24,19 @@
   (:require [arthur.domain.clip :as clip]
             [arthur.audio.mix :as mix]
             [arthur.demo.stage :as stage]
+            [arthur.domain.feature :as feature]
             [arthur.domain.project :as project]
             [arthur.domain.wire :as wire]
+            [arthur.events.footage :as footage]
             [arthur.events.playback :as pb]
             [arthur.footage.store :as store]
             [arthur.flow.address :as address]
+            [arthur.flow.ingest :as ingest]
+            [arthur.flow.regenerate :as regenerate]
             [arthur.flow.source :as source]
+            [arthur.flow.take :as take]
             [arthur.fx.http :as http]
+            [arthur.synth :as synth]
             [re-frame.core :as rf]))
 
 (defn- analysis-payload [analysis]
@@ -130,7 +136,8 @@
                                               (http/PUT
                                                (str "/api/analyses/" (:id analysis))
                                                #js {:source_blocks
-                                                    (into-array (map :key (vals source-blocks)))})))))))
+                                                    (into-array (map #(get-in source-blocks [% :key])
+                                                                     source/roles))})))))))
                       (.then (fn [_] (upload-missing! doc)))
                       (.then (fn [uploaded]
                                (-> (http/PUT (str "/api/projects/" pid)
@@ -200,6 +207,137 @@
                  (js/console.error error)
                  (rf/dispatch [::failed (or (ex-message error) (str error))]))))))
 
+(defonce ^:private retained-source (atom nil))
+(defonce ^:private retained-interior (atom nil))
+
+(defn- measure-crops! [inputs settings]
+  ;; Existing analyses without an interior block pay this once. One crop per
+  ;; event-loop turn keeps playback responsive during that backfill.
+  (if (or (:interior inputs) (not (:crops inputs)))
+    (js/Promise.resolve inputs)
+    (js/Promise.
+     (fn [resolve reject]
+       (let [crops (:crops inputs)
+             measured (atom [])]
+         (letfn [(step [i]
+                   (if (= i (count crops))
+                     (resolve (assoc inputs :interior @measured))
+                     (try
+                       (swap! measured conj (source/measure-crop settings (nth crops i)))
+                       (js/setTimeout #(step (inc i)) 0)
+                       (catch :default error (reject error)))))]
+           (step 0)))))))
+
+(defn- retained-interior! [analysis settings inputs]
+  (let [frames (count (:crops inputs))
+        block-key (source/interior-key analysis settings frames)]
+    (-> (http/GET (str "/api/blocks/" block-key))
+        (.then (fn [block]
+                 (assoc inputs
+                        :interior (source/unpack-interior block settings frames)
+                        :interior-key block-key)))
+        (.catch (fn [error]
+                  (if (= 404 (:status (ex-data error)))
+                    (-> (measure-crops! (dissoc inputs :interior) settings)
+                        (.then (fn [measured]
+                                 (let [{:keys [key descriptor data]}
+                                       (source/interior-block analysis settings
+                                                              (:interior measured))]
+                                   (-> (upload-missing!
+                                        #js {:blocks #js [#js {:key key
+                                                                :descriptor descriptor
+                                                                :data data}]})
+                                       (.then (fn [_]
+                                                (assoc measured :interior-key block-key))))))))
+                    (throw error)))))))
+
+(defn- source-for! [entry]
+  (if-let [inputs (:source-inputs entry)]
+    (js/Promise.resolve inputs)
+    (let [analysis (get-in entry [:clip :analysis])]
+      (if (= (:id analysis) (:id @retained-source))
+        (:promise @retained-source)
+        (let [promise
+              (if (= "synth" (:detector analysis))
+                (js/Promise.resolve
+                 {:dense (synth/synth-dense (:frames analysis) {:seed (:seed analysis)})})
+                (-> (ingest/manifest! (:footage-id entry))
+                    (.then (fn [manifest]
+                             (-> (footage/saved-source! (:id analysis)
+                                                        [(:width manifest)
+                                                         (:height manifest)])
+                                 (.then (fn [inputs]
+                                          (when-not inputs
+                                            (throw (ex-info "saved analysis has no source blocks" {})))
+                                          (assoc inputs :presence (:presence manifest)))))))))]
+          (do
+            (reset! retained-source {:id (:id analysis) :promise promise})
+            promise))))))
+
+(defn- inputs-for-edit! [entry edit inputs]
+  (let [{clip :changed fids :features} (regenerate/plan (:clip entry) edit)
+        teeth (first (filter #(= :teeth (get-in clip [:features % :area])) fids))]
+    (if (and teeth (:crops inputs))
+      (let [settings (merge take/knobs (feature/effective-params clip teeth))
+            analysis (get-in clip [:analysis :id])
+            frames (count (:crops inputs))
+            key (source/interior-key analysis settings frames)]
+        (if (and (:interior inputs)
+                 (or (= (:interior-key inputs) key)
+                     (and (nil? (:interior-key inputs))
+                          (= key (source/interior-key analysis take/knobs frames)))))
+          (js/Promise.resolve inputs)
+          (if (= key (:key @retained-interior))
+            (:promise @retained-interior)
+            (let [promise (retained-interior! analysis settings inputs)]
+              (reset! retained-interior {:key key :promise promise})
+              promise))))
+      (js/Promise.resolve inputs))))
+
+(rf/reg-fx
+ ::preview-settings!
+ (fn [{:keys [id entry edit request]}]
+   (-> (source-for! entry)
+       (.then (fn [inputs] (inputs-for-edit! entry edit inputs)))
+       (.then (fn [inputs]
+                (regenerate/change (assoc entry :source-inputs inputs) edit)))
+       (.then (fn [changed]
+                (rf/dispatch [::settings-previewed id request changed])))
+       (.catch (fn [error]
+                 (js/console.error error)
+                 (rf/dispatch [::failed (or (ex-message error) (str error))]))))))
+
+(rf/reg-event-fx
+ ::preview-settings
+ (fn [{:keys [db]} [_ edit]]
+   (let [id (:clip/current db)
+         entry (store/entry id)]
+     (if (or (get-in db [:project :busy?]) (nil? (:analysis (:clip entry))))
+       {}
+       (let [plan (regenerate/plan (:clip entry) edit)
+             report (select-keys plan [:features :roles])
+             request (inc (or (:preview-request db) 0))]
+         (js/console.info "arthur regeneration" (clj->js (assoc report :edit edit)))
+         {:db (-> db
+                  (assoc :preview-request request)
+                  (update :project merge {:status "previewing…"})
+                  (assoc :regeneration (assoc report :edit edit)))
+          ::preview-settings! {:id id :entry entry :edit edit
+                               :request request}})))))
+
+(rf/reg-sub ::regeneration (fn [db _] (:regeneration db)))
+
+(rf/reg-event-fx
+ ::settings-previewed
+ (fn [{:keys [db]} [_ previous request entry]]
+   (if (and (= previous (:clip/current db))
+            (= request (:preview-request db)))
+     (let [id (store/install! entry "edited")]
+       {:db (-> db
+                (assoc :clip/current id)
+                (update :project merge {:status "preview · unsaved"}))})
+     {})))
+
 ;; ---------------------------------------------------------------------------
 ;; events
 
diff --git a/frontend/src/arthur/flow/address.cljs b/frontend/src/arthur/flow/address.cljs
index 29fe8b6..f5171d1 100644
--- a/frontend/src/arthur/flow/address.cljs
+++ b/frontend/src/arthur/flow/address.cljs
@@ -148,6 +148,8 @@
    "source/dense" []
    "source/detected" []
    "source/crops" []
+   "source/interior" [:blob-grow :cavity-erode :min-area :teeth-verts
+                      :tongue-reject :top-bias]
    "head-pos"   [:anchor-avg]
    "head-rot"   [:anchor-avg]
    "head-scale" [:anchor-avg]
diff --git a/frontend/src/arthur/flow/freeze.cljs b/frontend/src/arthur/flow/freeze.cljs
index b35cf8d..0080f4e 100644
--- a/frontend/src/arthur/flow/freeze.cljs
+++ b/frontend/src/arthur/flow/freeze.cljs
@@ -425,6 +425,34 @@
        [:xform :pos]    (ch/framed [(- (/ w 2) (:x c))
                                     (- (* 0.25 h) (:y c))])})))
 
+(defn- mouth-part [absent? obs
+                   {:keys [analysis verts anchor-avg contour-avg aperture-cut] :as params}
+                   {:keys [outer inner] :as inputs}]
+  (let [rings (block {:role "geom" :analysis (:id analysis) :params params
+                      :tracks ["outer" "inner"]}
+                     {:type "int16" :scale geom-scale
+                      :features [:mouth :mouth] :absent? absent?}
+                     obs [(rings->flat outer verts) (rings->flat inner verts)])
+        prov (fn [by]
+               {:by by :analysis (:id analysis)
+                :params {:anchor-avg anchor-avg :contour-avg contour-avg
+                         :verts verts}})]
+    {:nodes {:mouth
+             {:id :mouth :name "mouth" :kind :poly :parent :head :z "a1"
+              :channels {[:geom :pts] (dense rings 0 (prov :roto/lips-outer))
+                         [:style :color] (ch/framed :skin-dark)}}
+             :mouth-in
+             {:id :mouth-in :name "mouth interior" :kind :poly
+              :parent :mouth :z "a2"
+              :channels {[:geom :pts] (dense rings 1 (prov :roto/lips-inner))
+                         [:style :color] (ch/framed :mouth-dark)
+                         [:vis] (visibility params inputs
+                                            {:by :roto/mouth-aperture
+                                             :analysis (:id analysis)
+                                             :params {:anchor-avg anchor-avg
+                                                      :aperture-cut aperture-cut}})}}}
+     :store (stored rings)}))
+
 (defn- feature-parts
   "Freeze eyes and brows into their own dense blocks and scene nodes. This owns
   only representation: the landmark correspondence, blink and pose choices have
@@ -445,20 +473,23 @@
         ;; feature each one follows, in the same order. The two vectors are read
         ;; together on purpose: this is the mapping `pack` cannot check for itself,
         ;; and `each-dense-track-follows-its-own-features-presence` is what pins it.
-        eye-block (named "eyes"
+        eye-block (when eyes (named "eyes"
                          ["lash-r" "lid-r" "lash-l" "lid-l"]
                          [:eye-r :eye-r :eye-l :eye-l]
                          "int16"
                          (mapv #(rings->flat % eye-verts)
                                [(:lash-r eyes) (:lid-r eyes)
-                                (:lash-l eyes) (:lid-l eyes)]))
-        iris-block (named "iris-pos" ["iris-r" "iris-l"] [:eye-r :eye-l] "float32"
-                          [(:iris-r eyes) (:iris-l eyes)])
-        brow-block (named "brows" ["ring-r" "ring-l"] [:brow-r :brow-l] "int16"
+                                (:lash-l eyes) (:lid-l eyes)])))
+        iris-block (when eyes
+                     (named "iris-pos" ["iris-r" "iris-l"] [:eye-r :eye-l] "float32"
+                            [(:iris-r eyes) (:iris-l eyes)]))
+        brow-block (when brows
+                     (named "brows" ["ring-r" "ring-l"] [:brow-r :brow-l] "int16"
                           (mapv #(rings->flat % brow-verts)
-                                [(:ring-r brows) (:ring-l brows)]))
-        brow-pos-block (named "brow-pos" ["pos-r" "pos-l"] [:brow-r :brow-l] "float32"
-                              [(:pos-r brows) (:pos-l brows)])
+                                [(:ring-r brows) (:ring-l brows)])))
+        brow-pos-block (when brows
+                         (named "brow-pos" ["pos-r" "pos-l"] [:brow-r :brow-l] "float32"
+                                [(:pos-r brows) (:pos-l brows)]))
         eye-node (fn [id z track]
                    {:id id :name (clojure.core/name id) :kind :poly :parent :head :z z
                     :channels {[:geom :pts] (dense eye-block track
@@ -477,12 +508,18 @@
                      :stencil parent
                      :channels {[:xform :pos] (dense iris-block track
                                                      (provenance :roto/gaze nil))
-                                [:geom :radius] (ch/framed radius)
+                                [:geom :radius] (assoc (ch/framed radius)
+                                                      :generated
+                                                      (provenance :roto/iris-size
+                                                                  {:iris-size (:iris-size params)}))
                                 [:style :color] (ch/framed :iris)}})
         pupil-node (fn [id parent]
                      {:id id :name (clojure.core/name id) :kind :rect :parent parent :z "a1"
                       :stencil parent
-                      :channels {[:geom :size] (ch/framed (:pupil-size eyes))
+                      :channels {[:geom :size] (assoc (ch/framed (:pupil-size eyes))
+                                                    :generated
+                                                    (provenance :roto/pupil-size
+                                                                {:pupil-size (:pupil-size params)}))
                                  [:style :color] (ch/framed :pupil)}})
         brow-node (fn [id z track]
                     {:id id :name (clojure.core/name id) :kind :poly :parent :head :z z
@@ -491,17 +528,21 @@
                                 [:xform :pos] (dense brow-pos-block track
                                                       (provenance :roto/brow-raise nil))
                                 [:style :color] (ch/framed :brow)}})]
-    {:nodes {:eye-r (eye-node :eye-r "a2" 0)
+    {:nodes (merge
+             (when eyes
+               {:eye-r (eye-node :eye-r "a2" 0)
              :eye-r-in (inner-node :eye-r-in :eye-r "a1" 1 (:shut-r eyes))
              :iris-r (iris-node :iris-r :eye-r-in 0 (:radius-r eyes))
              :pupil-r (pupil-node :pupil-r :iris-r)
              :eye-l (eye-node :eye-l "a3" 2)
              :eye-l-in (inner-node :eye-l-in :eye-l "a1" 3 (:shut-l eyes))
              :iris-l (iris-node :iris-l :eye-l-in 1 (:radius-l eyes))
-             :pupil-l (pupil-node :pupil-l :iris-l)
-             :brow-r (brow-node :brow-r "a4" 0)
-             :brow-l (brow-node :brow-l "a5" 1)}
-     :store (stored eye-block iris-block brow-block brow-pos-block)}))
+             :pupil-l (pupil-node :pupil-l :iris-l)})
+             (when brows
+               {:brow-r (brow-node :brow-r "a4" 0)
+                :brow-l (brow-node :brow-l "a5" 1)}))
+     :store (apply stored (remove nil?
+                                  [eye-block iris-block brow-block brow-pos-block]))}))
 
 (defn- interior-part
   "Freeze the pixel-derived radial contour under the mouth cavity. Missing
@@ -536,6 +577,44 @@
                          [:vis] (keyed-visibility shown generated)}}}
      :store (stored blk)}))
 
+(defn part
+  "A feature type's nodes and addressed blocks, with no clip scaffold."
+  [area params {:keys [detected presence] :as measured}]
+  (let [absent? (when (or detected presence)
+                  (fn [id f]
+                    (or (and detected (not (nth detected f true)))
+                        (and (contains? presence id)
+                             (not (nth (get presence id) f))))))
+        obs {:detected detected :presence presence}]
+    (case area
+      :mouth (mouth-part absent? obs params measured)
+      :eye (feature-parts absent? obs params (select-keys measured [:eyes]))
+      :brow (feature-parts absent? obs params (select-keys measured [:brows]))
+      :teeth (interior-part params absent? obs (:teeth measured))
+      (throw (ex-info "unknown frozen feature type" {:area area})))))
+
+(defn head-part
+  "Freeze only the measured head transform from an already conditioned anchor."
+  [{:keys [analysis anchor-avg] :as params} {:keys [transforms detected presence]}]
+  (let [absent? (when (or detected presence)
+                  (fn [_ f] (and detected (not (nth detected f true)))))
+        inv (mapv invert transforms)
+        xf (fn [role f]
+             (block {:role role :analysis (:id analysis) :params params
+                     :tracks [role]}
+                    {:type "float32" :features [nil] :absent? absent?}
+                    {:detected detected}
+                    [(mapv f inv)]))
+        pos (xf "head-pos" (fn [t] [(:tx t) (:ty t)]))
+        rot (xf "head-rot" (fn [t] [(:theta t)]))
+        scale (xf "head-scale" (fn [t] [(:s t) (:s t)]))
+        prov {:by :anchor/similarity :analysis (:id analysis)
+              :params {:anchor-avg anchor-avg}}]
+    {:measured {[:xform :pos] (dense pos 0 prov)
+                [:xform :rot] (dense rot 0 prov)
+                [:xform :scale] (dense scale 0 prov)}
+     :store (stored pos rot scale)}))
+
 ;; ---------------------------------------------------------------------------
 ;; the clip
 
@@ -624,12 +703,7 @@
         prov    (fn [by extra]
                   {:by by :analysis (:id analysis)
                    :params (merge {:anchor-avg anchor-avg} extra)})
-        rings   (block {:role "geom" :analysis (:id analysis) :params params
-                        :tracks ["outer" "inner"]}
-                       {:type "int16" :scale geom-scale
-                        :features [:mouth :mouth] :absent? absent?}
-                       obs
-                       [(rings->flat outer verts) (rings->flat inner verts)])
+        mouth   (mouth-part absent? obs params inputs)
         ;; The anchor, inverted and split into its three components. Three blocks
         ;; and not one: they are three channels, they have three strides, and a
         ;; single block would need a per-component offset table to say so.
@@ -653,7 +727,6 @@
         ;; `anchor avg` and on its own cut and NOT on `contour avg`, because
         ;; measure reports the inner ring's own height and nothing smooths it.
         anchor-prov (prov :anchor/similarity nil)
-        roto    (fn [by] (prov by {:verts verts :contour-avg contour-avg}))
         features (when (and eyes brows) (feature-parts absent? obs params inputs))
         interior (when teeth (interior-part params absent? obs teeth))
         built   {:name   name
@@ -710,31 +783,13 @@
                   {:id :head :name "head" :kind :group :parent :face :z "a1"
                    :measured {[:xform :pos]   (dense pos   0 anchor-prov)
                               [:xform :rot]   (dense rot   0 anchor-prov)
-                              [:xform :scale] (dense scale 0 anchor-prov)}}
-
-                  ;; The outer lip ring is the dark band OUTSIDE the interior, and
-                  ;; that three-layer structure — dark ring, pale interior, teeth
-                  ;; — is what makes a flat shape read as an opening rather than
-                  ;; as a blob. So it keeps every frame and is never hidden.
-                  :mouth
-                  {:id :mouth :name "mouth" :kind :poly :parent :head :z "a1"
-                   :channels {[:geom :pts]    (dense rings 0 (roto :roto/lips-outer))
-                              [:style :color] (ch/framed :skin-dark)}}
-
-                  :mouth-in
-                  {:id :mouth-in :name "mouth interior" :kind :poly
-                   :parent :mouth :z "a2"
-                   :channels {[:geom :pts]    (dense rings 1 (roto :roto/lips-inner))
-                              [:style :color] (ch/framed :mouth-dark)
-                              [:vis] (visibility params inputs
-                                                 (prov :roto/mouth-aperture
-                                                       {:aperture-cut aperture-cut}))}}}
-                    (:nodes features) (:nodes interior))}}}
+                              [:xform :scale] (dense scale 0 anchor-prov)}}}
+                    (:nodes mouth) (:nodes features) (:nodes interior))}}}
         ;; Tier 2, behind a handle, and now behind a content address: every key is
         ;; a sha256 over the analysis, the settings and the absence data that
         ;; produced the bytes under it. Nothing above this line changed when they
         ;; stopped being "take/geom", which is the point of a handle.
-        store   (merge (stored rings pos rot scale)
+        store   (merge (stored pos rot scale) (:store mouth)
                        (:store features) (:store interior))]
     (doseq [id (keys presence)]
       (when-not (contains? (:features built) id)
diff --git a/frontend/src/arthur/flow/regenerate.cljs b/frontend/src/arthur/flow/regenerate.cljs
new file mode 100644
index 0000000..7a01b64
--- /dev/null
+++ b/frontend/src/arthur/flow/regenerate.cljs
@@ -0,0 +1,125 @@
+(ns arthur.flow.regenerate
+  "Recompute a changed feature from retained source tracks, then replace only
+  channels owned by that feature. Upload remains project/save's ordinary job."
+  (:require [arthur.domain.clip :as clip]
+            [arthur.domain.feature :as feature]
+            [arthur.domain.params :as params]
+            [arthur.flow.address :as address]
+            [arthur.flow.freeze :as freeze]
+            [arthur.flow.take :as take]))
+
+(defn- settings [clip fid]
+  (let [f (get-in clip [:features fid])
+        mouth (first (for [[id peer] (:features clip)
+                           :when (and (= :mouth (:area peer))
+                                      (= (:subject f) (:subject peer)))] id))]
+    (cond-> (feature/effective-params clip fid)
+      (and (= :teeth (:area f)) mouth)
+      (assoc :aperture-cut (:aperture-cut (feature/effective-params clip mouth))))))
+
+(defn- replace-feature [entry fragment fid]
+  (let [paths (for [id (get-in entry [:clip :features fid :nodes])
+                    [prop channel] (get-in fragment [:nodes id :channels])
+                    :when (:generated channel)]
+                [id prop channel])]
+    (-> (reduce (fn [entry [id prop channel]]
+                  (let [at [:clip :timelines clip/root-id :nodes id :channels prop]
+                        old (get-in entry at)]
+                    (assoc-in entry at
+                              (cond-> channel
+                                (contains? old :over) (assoc :over (:over old))))))
+                entry paths)
+        (update :store merge (:store fragment)))))
+
+(defn plan
+  "The changed document and feature IDs an edit dirties. Also reports tier-2
+  block roles from the existing address table for the debug UI."
+  [clip {:keys [scope id knob value]}]
+  (let [area (get-in params/definitions [knob :area])
+        collection (case scope
+                     :subject :subjects :feature :features :group :groups
+                     (throw (ex-info "unknown setting scope" {:scope scope})))
+        owner (get-in clip [collection id])]
+    (when-not (and owner (params/valid-value? knob value)
+                   (case scope
+                     :subject (= area :subject)
+                     :feature (= area (:area owner))
+                     :group (and (= area :eye) (= :eye-pair (:kind owner)))))
+      (throw (ex-info "invalid scoped setting" {:scope scope :id id
+                                                :knob knob :value value})))
+    (let [changed (assoc-in clip [collection id :params knob] value)
+          subject (if (= scope :subject) id (:subject owner))
+          members (case scope
+                    :subject (for [[fid f] (:features clip)
+                                   :when (= subject (:subject f))] fid)
+                    :feature [id]
+                    :group (:members owner))
+          members (if (= knob :contour-avg)
+                    (remove #(= :teeth (get-in clip [:features % :area])) members)
+                    members)
+          members (if (= knob :aperture-cut)
+                    (concat members (for [[fid f] (:features clip)
+                                       :when (and (= subject (:subject f))
+                                                  (= :teeth (:area f)))] fid))
+                    members)]
+      {:changed changed
+       :features (vec (filter #(not= (settings clip %) (settings changed %))
+                              (distinct members)))
+       :roles (address/invalidates knob)})))
+
+(defn- change-take
+  "One scoped static edit. `source-inputs` contains dense landmarks and, when
+  teeth are dirty, retained pixel measurements. No IO or app-db here."
+  [{:keys [clip source-inputs] :as entry} edit]
+  (let [{changed :changed fids :features} (plan clip edit)]
+    (when-not (:dense source-inputs)
+      (throw (ex-info "regeneration needs retained source landmarks" {})))
+    (if (empty? fids)
+      (assoc entry :clip changed)
+      (let [base-params (merge take/knobs
+                             {:fps (:fps clip)
+                              :aspect (get-in clip [:analysis :aspect])
+                              :analysis (:analysis clip)})
+          base (delay (take/anchor-base
+                       (merge base-params (settings changed (first fids)))
+                       source-inputs))
+          entry (reduce
+                 (fn [entry fid]
+                   (let [part-area (get-in changed [:features fid :area])
+                           p (merge base-params (settings changed fid))
+                           _ (when (and (= part-area :teeth)
+                                        (nil? (:interior source-inputs)))
+                               (throw (ex-info "teeth regeneration needs retained pixel measurements"
+                                               {:feature fid})))
+                           measured (take/measure-part part-area p source-inputs @base)]
+                       (replace-feature entry (freeze/part part-area p measured) fid)))
+                 (assoc entry :clip changed) fids)]
+      (if (= :anchor-avg (:knob edit))
+        (let [p (merge base-params
+                       (settings changed (first fids)))
+              baked (freeze/head-part p @base)
+              old-head (get-in clip [:timelines :main :nodes :head])
+              measured (:measured baked)]
+          (cond-> (-> entry
+                      (assoc-in [:clip :timelines :main :nodes :head :measured] measured)
+                      (update :store merge (:store baked)))
+            (= (:channels old-head) (:measured old-head))
+            (assoc-in [:clip :timelines :main :nodes :head :channels] measured)))
+        entry)))))
+
+(defn change
+  "A take edits its root timeline. A stage edits the shared symbol timeline;
+  every instance then reads the same new channels on its next paint."
+  [{:keys [clip] :as entry} edit]
+  (if-let [symbol (some :timeline (vals (:features clip)))]
+    (let [original (:timelines clip)
+          take (assoc clip :timelines
+                      {:main (assoc (get original symbol) :id :main)})
+          changed (change-take (assoc entry :clip take) edit)]
+      (assoc changed :clip
+             (-> (:clip changed)
+                 (assoc :timelines
+                        (assoc original symbol
+                               (assoc (get-in changed [:clip :timelines :main])
+                                      :id symbol))))))
+    (change-take entry edit)))
diff --git a/frontend/src/arthur/flow/source.cljs b/frontend/src/arthur/flow/source.cljs
index c196577..47c1aaa 100644
--- a/frontend/src/arthur/flow/source.cljs
+++ b/frontend/src/arthur/flow/source.cljs
@@ -1,14 +1,76 @@
 (ns arthur.flow.source
-  "The pixel-dependent result of analyzing footage, stored as three ordinary
-  content-addressed blocks. Everything after this boundary can run without PNGs
-  or MediaPipe. The mouth crops hold raw pixels and an un-eroded lip ring."
+  "Retained analysis: three raw source blocks and an optional addressed interior
+  measurement block. Everything after this boundary can run without PNGs or
+  MediaPipe. Mouth crops retain pixels for settings that change the measurement."
   (:require [arthur.domain.landmarks :as lm]
+            [arthur.domain.params :as params]
             [arthur.domain.wire :as wire]
             [arthur.flow.address :as address]
             [arthur.flow.measure.interior :as interior]))
 
 (def roles ["source/dense" "source/detected" "source/crops"])
 
+(defn- interior-address [analysis settings frames]
+  (let [verts (:teeth-verts settings)
+        stride (+ 2 (* 2 verts))]
+    (address/block {:role "source/interior" :analysis analysis
+                    :params settings
+                    :tracks ["contrast" "area" "contour"]
+                    :features [] :observation nil
+                    :layout {:type "float64" :frames frames :verts verts
+                             :stride stride}})))
+
+(defn interior-key [analysis settings frames]
+  (:key (interior-address analysis settings frames)))
+
+(defn interior-block
+  "Retain pixel measurements before any head-local transform or smoothing."
+  [analysis settings measures]
+  (let [frames (count measures)
+        {:keys [key descriptor]}
+        (interior-address analysis settings frames)
+        verts (:teeth-verts settings)
+        stride (+ 2 (* 2 verts))
+        data (js/Float64Array. (* frames stride))]
+    (doseq [f (range frames)]
+      (let [{:keys [contrast area contour]} (nth measures f)
+            at (* f stride)]
+        (aset data at (or contrast 0))
+        (aset data (inc at) (or area 0))
+        (if contour
+          (do
+            (when-not (= verts (count contour))
+              (throw (ex-info "interior contour vertex count disagrees with settings"
+                              {:frame f :expected verts :actual (count contour)})))
+            (doseq [i (range verts)]
+              (aset data (+ at 2 (* 2 i)) (:x (nth contour i)))
+              (aset data (+ at 3 (* 2 i)) (:y (nth contour i)))))
+          (aset data (+ at 2) js/NaN))))
+    {:role "source/interior" :key key :descriptor descriptor :data data}))
+
+(defn unpack-interior [^js response settings frames]
+  (let [descriptor (js->clj (js/JSON.parse (.-descriptor response))
+                            :keywordize-keys true)
+        layout (:layout descriptor)
+        data (wire/typed (:type layout) (.-data response))
+        verts (:teeth-verts settings)
+        stride (+ 2 (* 2 verts))]
+    (when-not (and (= "source/interior" (:role descriptor))
+                   (= frames (:frames layout)) (= verts (:verts layout))
+                   (= stride (:stride layout))
+                   (= (* frames stride) (.-length data)))
+      (throw (ex-info "saved interior block has the wrong layout"
+                      {:layout layout :frames frames :verts verts})))
+    (mapv (fn [f]
+            (let [at (* f stride)]
+              {:contrast (aget data at) :area (aget data (inc at))
+               :contour (when-not (js/Number.isNaN (aget data (+ at 2)))
+                          (mapv (fn [i]
+                                  {:x (aget data (+ at 2 (* 2 i)))
+                                   :y (aget data (+ at 3 (* 2 i)))})
+                                (range verts)))}))
+          (range frames))))
+
 (defn measure-crop
   "One mouth crop's interior, or the empty measurement for a frame with no face.
 
@@ -21,9 +83,6 @@
     (interior/measure params (:box crop) #js {:data (:data crop)})
     {:contour nil :contrast 0 :area 0 :debug nil}))
 
-(defn measure-crops [params crops]
-  (mapv #(measure-crop params %) crops))
-
 (defn- named [role analysis tracks layout data]
   (merge (address/block {:role role :analysis analysis :params {}
                          :tracks tracks :features [] :observation nil
@@ -31,12 +90,13 @@
          {:role role :data data}))
 
 (defn pack
-  "Dense landmarks, detection mask and raw RGBA mouth crops -> source blocks."
-  [analysis {:keys [dense detected crops]}]
+  "Dense landmarks, mask, crops and optional pixel measurements -> source blocks."
+  [analysis {:keys [dense detected crops interior]}]
   (let [frames (count dense)
         points (count (first dense))]
     (when-not (and (pos? frames) (pos? points)
                    (= frames (count detected) (count crops))
+                   (or (nil? interior) (= frames (count interior)))
                    (every? #(= points (count %)) dense))
       (throw (ex-info "source tracks must have the same frame and landmark counts"
                       {:frames frames :points points})))
@@ -59,14 +119,16 @@
             (aset landmarks (+ base 2) z)))
         (when-let [crop (nth crops f)]
           (.set pixels (:data crop) (nth offsets f))))
-      {"source/dense" (named "source/dense" analysis ["landmarks"]
+      (cond-> {"source/dense" (named "source/dense" analysis ["landmarks"]
                               {:type "float64" :frames frames :points points :stride (* 3 points)}
                               landmarks)
        "source/detected" (named "source/detected" analysis ["detected"]
                                  {:type "uint8" :frames frames :stride 1} mask)
        "source/crops" (named "source/crops" analysis ["rgba"]
                               {:type "uint8" :frames frames :boxes boxes :offsets offsets}
-                              pixels)})))
+                              pixels)}
+        interior (assoc "source/interior"
+                        (interior-block analysis params/defaults interior))))))
 
 (defn wire-blocks [blocks]
   (into-array
@@ -80,7 +142,7 @@
    (map (fn [role]
           (let [{:keys [key descriptor data]} (get blocks role)]
             #js {:key key :descriptor descriptor :data data}))
-        roles)))
+        (filter #(contains? blocks %) (conj roles "source/interior")))))
 
 (defn unpack
   "The three block-detail responses -> inputs for measurement and freeze."
diff --git a/frontend/src/arthur/flow/take.cljs b/frontend/src/arthur/flow/take.cljs
index 37f50b2..2312820 100644
--- a/frontend/src/arthur/flow/take.cljs
+++ b/frontend/src/arthur/flow/take.cljs
@@ -60,6 +60,44 @@
            :detected detected
            :presence presence)))
 
+(defn anchor-base
+  "Shared upstream measurement for a feature regeneration."
+  [{:keys [aspect] :as params} {:keys [dense detected presence]}]
+  (let [fitted (anchor/fit {:aspect aspect} {:dense dense})]
+    (assoc (condition/anchor params fitted)
+           :detected detected :presence presence)))
+
+(defn measure-part
+  "Recompute one feature type through the shared conditioned anchor. A brow
+  reads the eye corners, and teeth read mouth aperture; these are input edges,
+  not requests to freeze those other features."
+  [area {:keys [aspect] :as params}
+   {:keys [dense detected interior presence]} {:keys [transforms] :as base}]
+  (let [mouth (fn []
+                (mouth/measure {:aspect aspect}
+                               {:dense dense :transforms transforms}))
+        eyes (fn []
+               (eyes/measure params {:dense dense :transforms transforms
+                                     :detected detected :presence presence}))]
+    (merge (select-keys base [:detected :presence])
+           (case area
+             :mouth (let [m (mouth)]
+                      {:outer (condition/contours params (:outer m))
+                       :inner (condition/contours params (:inner m))
+                       :aperture (:aperture m)})
+             :eye {:eyes (condition-eyes/apply-defaults params (eyes))}
+             :brow {:brows (condition-brows/apply-defaults
+                            params
+                            (brows/measure params {:dense dense :transforms transforms})
+                            (eyes))}
+             :teeth (let [aperture (:aperture (mouth))]
+                      {:teeth (condition-interior/apply-defaults
+                               params
+                               (mapv interior/head-local interior transforms
+                                     (repeat aspect))
+                               aperture)})
+             (throw (ex-info "unknown measured feature type" {:area area}))))))
+
 (defn build
   [params inputs]
   (freeze/clip params (measure params inputs)))
diff --git a/frontend/src/arthur/footage/store.cljs b/frontend/src/arthur/footage/store.cljs
index 75f3a38..8e60f26 100644
--- a/frontend/src/arthur/footage/store.cljs
+++ b/frontend/src/arthur/footage/store.cljs
@@ -22,7 +22,8 @@
   ([entry kind]
    (let [id (keyword kind (str (swap! serial inc)))]
      (when-let [old (:audio @loaded)]
-       (when (.startsWith old "blob:") (js/URL.revokeObjectURL old)))
+       (when (and (not= old (:audio entry)) (.startsWith old "blob:"))
+         (js/URL.revokeObjectURL old)))
      (reset! loaded (assoc entry :id id))
      id)))
 
diff --git a/frontend/src/arthur/ui/shell.cljs b/frontend/src/arthur/ui/shell.cljs
index 0a810eb..504d230 100644
--- a/frontend/src/arthur/ui/shell.cljs
+++ b/frontend/src/arthur/ui/shell.cljs
@@ -7,15 +7,103 @@
   why scrubbing at speed does not re-render the page."
   (:require [arthur.clock :as clock]
             [arthur.db :as db]
+            [arthur.domain.feature :as feature]
+            [arthur.domain.params :as params]
             [arthur.events.footage :as footage]
             [arthur.events.playback :as pb]
             [arthur.events.project :as project]
             [arthur.subs.playback :as sub]
             [arthur.subs.render :as render]
             [arthur.ui.player :as player]
-            [re-frame.core :as rf]))
+            [re-frame.core :as rf]
+            [reagent.core :as r]))
 
 (def ^:private zoom 2)
+(defonce ^:private selected-owner (r/atom nil))
+(defonce ^:private drafts (r/atom {}))
+
+(defn- setting-owners [clip]
+  (let [instances (for [[id node] (get-in clip [:timelines :main :nodes])
+                        :when (= :symbol (:kind node))] id)
+        instances (if (seq instances) (sort-by str instances) [nil])]
+    (vec (for [instance instances
+               [scope ids] [[:subject (:subjects clip)]
+                            [:feature (:features clip)]
+                            [:group (:groups clip)]]
+               id (sort-by str (keys ids))]
+           [scope id instance]))))
+
+(defn- slider-bounds [knob {:keys [type default min even?] upper :max}]
+  {:min (or min (if (= knob :blob-grow) -3 0))
+   :max (or upper (get {:verts 20 :eye-verts 16 :brow-verts 10
+                       :teeth-verts 20 :blob-grow 3 :top-bias 2
+                       :gaze-gain 4} knob)
+            (max 1 (* 2 default)))
+   :step (cond even? 2 (= type :integer) 1 :else 0.01)})
+
+(defn- controls []
+  (let [clip @(rf/subscribe [::render/clip])
+        busy? (:busy? @(rf/subscribe [::sub/project]))
+        report @(rf/subscribe [::project/regeneration])
+        owners (setting-owners clip)
+        [scope id instance :as owner] (if (some #{(deref selected-owner)} owners)
+                              @selected-owner (first owners))
+        area (case scope
+               :subject :subject
+               :feature (get-in clip [:features id :area])
+               :group :eye
+               nil)
+        values (case scope
+                 :subject (merge (params/for-area :subject)
+                                 (get-in clip [:subjects id :params]))
+                 :feature (when id (feature/effective-params clip id))
+                 :group (merge (params/for-area :eye)
+                               (get-in clip [:groups id :params]))
+                 nil)]
+    [:section.controls
+     [:label "active object "
+      [:select {:value (or (first (keep-indexed
+                                  (fn [i option] (when (= option owner) i)) owners)) 0)
+                :on-change #(reset! selected-owner
+                                    (nth owners (js/parseInt (.. % -target -value) 10)))}
+       (if (seq owners)
+         (doall (for [[i [kind object-id]] (map-indexed vector owners)]
+                  ^{:key i} [:option {:value i}
+                             (str (when-let [instance (nth (nth owners i) 2)]
+                                    (str (name instance) " / "))
+                                  (name kind) " · " (name object-id))]))
+         [:option {:value 0} "no tracked objects"])] ]
+     (when instance
+       [:div.shared-note "shared symbol · changes all seven stage instances"])
+     (when area
+       [:div.control-list
+        (doall
+         (for [[knob spec] (sort-by (comp str key) params/definitions)
+               :when (= area (:area spec))]
+           (let [draft-key [scope id knob]
+                 value (get @drafts draft-key (get values knob))
+                 {:keys [min max step]} (slider-bounds knob spec)]
+             ^{:key (str draft-key)}
+             [:label.control-row
+              [:span (name knob)]
+              [:input {:type "range" :min min :max max :step step :value value
+                       :disabled busy?
+                       :on-change (fn [event]
+                                    (let [s (.. event -target -value)
+                                          v (if (= :integer (:type spec))
+                                              (js/parseInt s 10)
+                                              (js/parseFloat s))]
+                                      (swap! drafts assoc draft-key v)
+                                      (rf/dispatch [::project/preview-settings
+                                                    {:scope scope :id id :knob knob
+                                                     :value v}]))) }]
+              [:output (str value)]])))])
+     (when report
+       [:pre.regeneration-debug
+        (str "dirty features: " (pr-str (:features report)) "\n"
+             "new block roles: " (if (seq (:roles report))
+                                   (pr-str (sort (:roles report))) "none (tier 1 only)")
+             "\n" (get-in @(rf/subscribe [::sub/project]) [:status]))])]))
 
 (defn- audio []
   (let [src @(rf/subscribe [::sub/audio])]
@@ -153,6 +241,7 @@
    [stage]
    [audio]
    [transport]
+   [controls]
    [:p.note
     "Upload a video, choose its footage, then load frames. Save the project to "
     "share the analyzed take without detecting frames again."]])
diff --git a/frontend/test/arthur/flow/regenerate_test.cljs b/frontend/test/arthur/flow/regenerate_test.cljs
new file mode 100644
index 0000000..0bfffbc
--- /dev/null
+++ b/frontend/test/arthur/flow/regenerate_test.cljs
@@ -0,0 +1,101 @@
+(ns arthur.flow.regenerate-test
+  (:require [cljs.test :refer [deftest is]]
+            [arthur.domain.project :as project]
+            [arthur.flow.address :as address]
+            [arthur.flow.regenerate :as regenerate]
+            [arthur.flow.take :as take]
+            [arthur.synth :as synth]))
+
+(def ^:private frames 40)
+(def ^:private inputs (delay {:dense (synth/synth-dense frames {:seed 9})}))
+(def ^:private initial
+  (delay
+    (let [p (merge take/knobs
+                   {:name "regen" :fps 30 :aspect 1 :stage [320 200]
+                    :expose 1 :head :as-filmed
+                    :analysis (address/analysis
+                               {:detector "synth" :version "mulberry32"
+                                :seed 9 :frames frames :fps 30 :aspect 1})})]
+      (assoc (take/build p @inputs) :source-inputs @inputs))))
+
+(defn- full-at [change]
+  (take/build
+   (merge take/knobs
+          {:name "regen" :fps 30 :aspect 1 :stage [320 200]
+           :expose 1 :head :as-filmed
+           :analysis (get-in @initial [:clip :analysis])}
+          change)
+   @inputs))
+
+(defn- channel [entry node path]
+  (get-in entry [:clip :timelines :main :nodes node :channels path]))
+
+(deftest eye-rebuild-is-confined-to-the-edited-feature
+  (let [before @initial
+        after (regenerate/change before
+                 {:scope :feature :id :eye-r :knob :gaze-gain :value 2})]
+    (is (not= (channel before :iris-r [:xform :pos])
+              (channel after :iris-r [:xform :pos])))
+    (is (= (channel before :iris-l [:xform :pos])
+           (channel after :iris-l [:xform :pos])))
+    (is (= (channel before :mouth [:geom :pts])
+           (channel after :mouth [:geom :pts])))
+    (is (= (get-in before [:clip :timelines :main :nodes :face])
+           (get-in after [:clip :timelines :main :nodes :face])))
+    (is (= (channel (full-at {:gaze-gain 2}) :iris-r [:xform :pos])
+           (channel after :iris-r [:xform :pos])))))
+
+(deftest framed-eye-size-needs-no-new-dense-block
+  (let [before @initial
+        after (regenerate/change before
+                 {:scope :feature :id :eye-r :knob :iris-size :value 0.6})]
+    (is (not= (channel before :iris-r [:geom :radius])
+              (channel after :iris-r [:geom :radius])))
+    (is (= (channel before :iris-l [:geom :radius])
+           (channel after :iris-l [:geom :radius])))
+    (is (= (channel (full-at {:iris-size 0.6}) :iris-r [:geom :radius])
+           (channel after :iris-r [:geom :radius])))
+    (is (= (set (keys (:store before))) (set (keys (:store after)))))))
+
+(deftest mouth-edit-leaves-the-head-and-eye-alone
+  (let [before @initial
+        after (regenerate/change before
+                 {:scope :feature :id :mouth :knob :verts :value 10})]
+    (is (not= (channel before :mouth [:geom :pts])
+              (channel after :mouth [:geom :pts])))
+    (is (= (get-in before [:clip :timelines :main :nodes :head])
+           (get-in after [:clip :timelines :main :nodes :head])))
+    (is (= (channel before :eye-r [:geom :pts])
+           (channel after :eye-r [:geom :pts])))
+    (is (= (channel (full-at {:verts 10}) :mouth [:geom :pts])
+           (channel after :mouth [:geom :pts])))))
+
+(deftest subject-edit-recomputes-head-and-keeps-authored-placement
+  (let [before @initial
+        after (regenerate/change before
+                {:scope :subject :id :face-1 :knob :anchor-avg :value 4})
+        full (full-at {:anchor-avg 4})]
+    (is (not= (get-in before [:clip :timelines :main :nodes :head :measured])
+              (get-in after [:clip :timelines :main :nodes :head :measured])))
+    (is (= (get-in full [:clip :timelines :main :nodes :head :measured])
+           (get-in after [:clip :timelines :main :nodes :head :measured])))
+    (is (= (get-in before [:clip :timelines :main :nodes :face])
+           (get-in after [:clip :timelines :main :nodes :face])))))
+
+(deftest contour-edit-does-not-rebuild-head-or-teeth
+  (let [before @initial
+        after (regenerate/change before
+                {:scope :subject :id :face-1 :knob :contour-avg :value 3})]
+    (is (= (get-in before [:clip :timelines :main :nodes :head])
+           (get-in after [:clip :timelines :main :nodes :head])))
+    (is (= (channel before :teeth [:geom :pts])
+           (channel after :teeth [:geom :pts])))))
+
+(deftest edited-take-still-round-trips-through-normal-save
+  (let [after (regenerate/change @initial
+                {:scope :group :id :eyes-1 :knob :iris-size :value 0.6})
+        wire (project/save "regen" after)
+        loaded (project/load "regen" (js/JSON.parse (js/JSON.stringify wire)))]
+    (is (= (:clip after) (:clip loaded)))
+    (is (= (channel after :iris-r [:geom :radius])
+           (channel loaded :iris-r [:geom :radius])))))
diff --git a/frontend/test/arthur/flow/source_test.cljs b/frontend/test/arthur/flow/source_test.cljs
index d5f3626..0f4312b 100644
--- a/frontend/test/arthur/flow/source_test.cljs
+++ b/frontend/test/arthur/flow/source_test.cljs
@@ -1,7 +1,25 @@
 (ns arthur.flow.source-test
   (:require [cljs.test :refer [deftest is]]
+            [arthur.domain.params :as params]
+            [arthur.domain.wire :as wire]
             [arthur.flow.source :as source]))
 
+(deftest pixel-measurements-have-their-own-addressed-block
+  (let [settings params/defaults
+        ring (mapv (fn [i] {:x (/ i 10) :y (/ (+ i 1) 20)})
+                   (range (:teeth-verts settings)))
+        measures [{:contour ring :contrast 0.7 :area 42}
+                  {:contour nil :contrast 0 :area 0}]
+        block (source/interior-block "sha256:analysis" settings measures)
+        response #js {:descriptor (:descriptor block)
+                      :data (wire/base64 (:data block))}]
+    (is (= (:key block)
+           (source/interior-key "sha256:analysis" settings 2)))
+    (is (= measures (source/unpack-interior response settings 2)))
+    (is (not= (:key block)
+              (source/interior-key "sha256:analysis"
+                                   (assoc settings :cavity-erode 0.2) 2)))))
+
 (deftest source-blocks-round-trip-without-source-images
   (let [face (vec (repeat 478 {:x 0.25 :y 0.5 :z -0.125}))
         pixels (js/Uint8ClampedArray. #js [12 24 36 255])
@@ -19,3 +37,12 @@
     (is (nil? (second (:crops out))))
     (is (= (mapv :key (vals blocks))
            (mapv :key (vals (source/pack "sha256:analysis" out)))))))
+
+(deftest fresh-source-includes-its-pixel-measurement-block
+  (let [face (vec (repeat 478 {:x 0.25 :y 0.5 :z -0.125}))
+        input {:dense [face] :detected [false] :crops [nil]
+               :interior [{:contour nil :contrast 0 :area 0}]}
+        blocks (source/pack "sha256:analysis" input)]
+    (is (contains? blocks "source/interior"))
+    (is (= 4 (.-length (source/upload-blocks blocks))))
+    (is (= 3 (count source/roles)))))
diff --git a/frontend/test/browser/take.mjs b/frontend/test/browser/take.mjs
index 1adf6ea..f1209d4 100644
--- a/frontend/test/browser/take.mjs
+++ b/frontend/test/browser/take.mjs
@@ -233,7 +233,8 @@ async function main() {
       if (probe && probe.drawn > 0) break;
       await sleep(100);
     }
-    if (!probe) throw new Error('no canvas.stage on the page — is `shadow-cljs watch app` running?');
+    if (!probe) throw new Error('no canvas.stage on the page — ' +
+      (page.logs.slice(0, 3).join(' | ') || 'is `shadow-cljs watch app` running?'));
 
     console.log(`\ncanvas ${probe.w}x${probe.h}, clip ${JSON.stringify(probe.selectedClip)}`);
 
@@ -393,6 +394,138 @@ async function main() {
     check(!back[0].selectedClip.includes('take'), 'the picture is the reopened document',
           JSON.stringify(back[0].selectedClip));
 
+    // The local 8625 study is optional in a fresh test database. When present,
+    // tune its shared symbol while its stage is playing.
+    const stageSource = await page.eval(`fetch('/api/projects/4379f900-bdd2-409b-acf6-32081f8ce01f')
+      .then(r => r.ok)`);
+    if (stageSource) {
+      check(await page.eval(CLICK('stage 8625')), 'the 8625 stage loads');
+      const stageLoaded = await statusMatching(/loaded 8625 stage study/, 160);
+      check(stageLoaded !== null, 'the 8625 stage is ready', stageLoaded ?? (await page.eval(STATUS)));
+      const eyeSelected = await page.eval(`(() => {
+        const select = document.querySelector('.controls select');
+        const option = [...select.options]
+          .find(o => o.textContent.trim() === 'left / feature · eye-r');
+        if (!option) return false;
+        select.value = option.value;
+        select.dispatchEvent(new Event('change', { bubbles: true }));
+        return true;
+      })()`);
+      check(eyeSelected, 'a stage instance exposes its tracked right eye');
+      await sleep(100);
+      const irisSlider = await page.eval(`(() => {
+        const row = [...document.querySelectorAll('.control-row')]
+          .find(row => row.querySelector('span')?.textContent === 'iris-size');
+        if (!row) return null;
+        const r = row.querySelector('input').getBoundingClientRect();
+        return { x: r.x + r.width * 0.9, y: r.y + r.height / 2 };
+      })()`);
+      check(irisSlider !== null, 'the stage eye has an iris-size slider');
+      if (irisSlider) {
+        check(await page.eval(CLICK('play')), 'the stage starts playing');
+        const startFrame = await page.eval(`Number(document.querySelector('.readout span').textContent.match(/\\d+/)[0])`);
+        await page.send('Input.dispatchMouseEvent', {
+          type: 'mousePressed', x: irisSlider.x, y: irisSlider.y, button: 'left', clickCount: 1,
+        });
+        await page.send('Input.dispatchMouseEvent', {
+          type: 'mouseReleased', x: irisSlider.x, y: irisSlider.y, button: 'left', clickCount: 1,
+        });
+        const preview = await statusMatching(/preview · unsaved/, 160);
+        const debug = await page.eval(`document.querySelector('.regeneration-debug')?.textContent ?? ''`);
+        check(preview !== null, 'the slider updates the stage preview', preview ?? debug);
+        check(debug.includes(':eye-r') && debug.includes('tier 1 only'),
+              'the panel reports the affected feature and tier', debug);
+        const endFrame = await page.eval(`Number(document.querySelector('.readout span').textContent.match(/\\d+/)[0])`);
+        check(endFrame > startFrame, 'playback continues during tuning', `${startFrame} -> ${endFrame}`);
+        await page.eval(CLICK('pause'));
+      }
+      const subjectSelected = await page.eval(`(() => {
+        const select = document.querySelector('.controls select');
+        const option = [...select.options]
+          .find(o => o.textContent.includes('subject · face-1'));
+        if (!option) return false;
+        select.value = option.value;
+        select.dispatchEvent(new Event('change', { bubbles: true }));
+        return true;
+      })()`);
+      check(subjectSelected, 'the stage exposes its tracked subject');
+      if (subjectSelected) {
+        await sleep(100);
+        const anchorSlider = await page.eval(`(() => {
+          const row = [...document.querySelectorAll('.control-row')]
+            .find(row => row.querySelector('span')?.textContent === 'anchor-avg');
+          if (!row) return null;
+          const r = row.querySelector('input').getBoundingClientRect();
+          return { x: r.x + r.width * 0.9, y: r.y + r.height / 2 };
+        })()`);
+        check(anchorSlider !== null, 'the subject has an anchor slider');
+        if (anchorSlider) {
+          const anchorStart = Date.now();
+          await page.send('Input.dispatchMouseEvent', {
+            type: 'mousePressed', x: anchorSlider.x, y: anchorSlider.y,
+            button: 'left', clickCount: 1,
+          });
+          await page.send('Input.dispatchMouseEvent', {
+            type: 'mouseReleased', x: anchorSlider.x, y: anchorSlider.y,
+            button: 'left', clickCount: 1,
+          });
+          let debug = '';
+          for (let i = 0; i < 160; i++) {
+            debug = await page.eval(`document.querySelector('.regeneration-debug')?.textContent ?? ''`);
+            if (debug.includes('head-pos')) break;
+            await sleep(250);
+          }
+          check(debug.includes('head-pos') && debug.includes(':teeth'),
+                'anchor invalidates the head and teeth', debug);
+          const preview = await statusMatching(/preview · unsaved/, 160);
+          check(preview !== null, 'the anchor edit finishes previewing',
+                preview ? `${Date.now() - anchorStart}ms` : (await page.eval(STATUS)));
+        }
+      }
+      const teethSelected = await page.eval(`(() => {
+        const select = document.querySelector('.controls select');
+        const option = [...select.options]
+          .find(o => o.textContent.trim() === 'left / feature · teeth');
+        if (!option) return false;
+        select.value = option.value;
+        select.dispatchEvent(new Event('change', { bubbles: true }));
+        return true;
+      })()`);
+      check(teethSelected, 'the stage exposes its tracked teeth');
+      if (teethSelected) {
+        await sleep(100);
+        const slider = await page.eval(`(() => {
+          const row = [...document.querySelectorAll('.control-row')]
+            .find(row => row.querySelector('span')?.textContent === 'cavity-erode');
+          if (!row) return null;
+          const r = row.querySelector('input').getBoundingClientRect();
+          return { x: r.x + r.width * 0.9, y: r.y + r.height / 2 };
+        })()`);
+        check(slider !== null, 'the teeth have a pixel-setting slider');
+        if (slider) {
+          await page.send('Input.dispatchMouseEvent', {
+            type: 'mousePressed', x: slider.x, y: slider.y,
+            button: 'left', clickCount: 1,
+          });
+          await page.send('Input.dispatchMouseEvent', {
+            type: 'mouseReleased', x: slider.x, y: slider.y,
+            button: 'left', clickCount: 1,
+          });
+          let debug = '';
+          for (let i = 0; i < 160; i++) {
+            debug = await page.eval(`document.querySelector('.regeneration-debug')?.textContent ?? ''`);
+            if (debug.includes('dirty features: [:teeth]')) break;
+            await sleep(250);
+          }
+          check(debug.includes('dirty features: [:teeth]'),
+                'the pixel setting invalidates only teeth', debug);
+          const preview = await statusMatching(/preview · unsaved/, 160);
+          check(preview !== null, 'the teeth edit finishes previewing',
+                preview ?? (await page.eval(STATUS)));
+        }
+      }
+    }
+
     // Exercise the actual file input and FormData path, then wait for the
     // extraction job's footage to appear in the server list.
     const uploadDir = mkdtempSync(join(tmpdir(), 'arthur-upload-'));