Only start saving camera after scene is ready (#7120)

src/components/EngineStream.tsx

@@ -406,11 +406,17 @@ export const EngineStream = (props: {
 
   // On various inputs save the camera state, in case we get disconnected.
   useEffect(() => {
+    // Only start saving after we are playing the stream (which means
+    // the scene is ready.)
+    // Also prevents us from stepping on the toes of the camera restoration.
+    if (engineStreamState.value !== EngineStreamState.Playing) return
+
     const onInput = () => {
       // Save the remote camera state to restore on stream restore.
       // Fire-and-forget because we don't know when a camera movement is
       // completed on the engine side (there are no responses to data channel
       // mouse movements.)
+
       sceneInfra.camControls.saveRemoteCameraState().catch(trap)
     }
 
@@ -426,7 +432,7 @@ export const EngineStream = (props: {
       window.document.removeEventListener('scroll', onInput)
       window.document.removeEventListener('touchend', onInput)
     }
-  }, [])
+  }, [engineStreamState.value])
 
   const isNetworkOkay =
     overallState === NetworkHealthState.Ok ||