From b97de59c84a751e0ac91af5fe539bc491edbc149 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miguel=20=C3=81ngel?= <miguel.sierra@heygen.com>
Date: Sat, 24 Oct 2026 22:35:57 +0000
Subject: [PATCH] fix(core): motion blur no longer blacks out videos inside
 sub-compositions (#6252)

* fix(core): motion blur no longer blacks out videos inside sub-compositions

* chore(core): drop the explanatory comment from the motion blur isolate move
---
 .../src/runtime/captureMotionBlur/index.test.ts    | 14 ++++++++++++++
 .../core/src/runtime/captureMotionBlur/index.ts    |  3 ++-
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/packages/core/src/runtime/captureMotionBlur/index.test.ts b/packages/core/src/runtime/captureMotionBlur/index.test.ts
index 7d6891c2a4..3979c6ebe6 100644
--- a/packages/core/src/runtime/captureMotionBlur/index.test.ts
+++ b/packages/core/src/runtime/captureMotionBlur/index.test.ts
@@ -705,6 +705,20 @@ describe("two-phase frames", () => {
     expect(el.hasAttribute(MOVER)).toBe(false);
   });
 
+  it("keeps the page visible until an engine frame is armed, so video frames inject into it", async () => {
+    installHtmlInCanvas();
+    const { root, h } = movingHost();
+    initCaptureMotionBlur(h);
+    const done = paintCaptureMotionBlur(0.5, { engineMode: true });
+    expect(root.hasAttribute(ONLY)).toBe(false);
+    releaseCaptureMotionBlurFrame();
+    expect(root.hasAttribute(ONLY)).toBe(true);
+    captureCanvas(root).dispatchEvent(new Event("paint"));
+    captureCanvas(root).dispatchEvent(new Event("paint"));
+    win.__hf_page_composite_resolve?.();
+    await done;
+  });
+
   it("shows plain DOM, not a half frame, when the engine's step runs before the background capture", async () => {
     installHtmlInCanvas();
     const { root, el, h } = movingHost();
diff --git a/packages/core/src/runtime/captureMotionBlur/index.ts b/packages/core/src/runtime/captureMotionBlur/index.ts
index d32c791224..dae1d42e55 100644
--- a/packages/core/src/runtime/captureMotionBlur/index.ts
+++ b/packages/core/src/runtime/captureMotionBlur/index.ts
@@ -527,7 +527,7 @@ function createInstance(host: CaptureMotionBlurHost, config: Config, form: HtmlI
             resolve();
           },
         };
-        if (pending.phase === "movers") isolate(pending);
+        if (pending.phase === "movers" && !engineMode) isolate(pending);
         if (engineMode) return;
         startTimer();
         src.requestPaint();
@@ -576,6 +576,7 @@ function createInstance(host: CaptureMotionBlurHost, config: Config, form: HtmlI
     arm: () => {
       if (!pending || pending.armed) return;
       pending.armed = true;
+      if (pending.phase === "movers") isolate(pending);
       pending.startTimer();
       src.requestPaint();
     },