try to do it without QCursor::setPos

interface/resources/controllers/keyboardMouse.json

@@ -213,6 +213,15 @@
             ]
         },
 
+        { "from": { "makeAxis" : ["Keyboard.MouseMoveLeft", "Keyboard.MouseMoveRight"] },
+          "to": "Actions.DeltaYaw",
+          "when": "Application.CaptureMouse",
+          "filters":
+            [
+                { "type": "scale", "scale": 0.2 }
+            ]
+        },
+
         { "from": { "makeAxis" : ["Keyboard.MouseMoveUp", "Keyboard.MouseMoveDown"] },
           "when": ["!Application.CameraSelfie", "!Application.CameraLookAt", "Keyboard.RightMouseButton"],
           "to": "Actions.DeltaPitch",
@@ -222,6 +231,15 @@
             ]
         },
 
+        { "from": { "makeAxis" : ["Keyboard.MouseMoveUp", "Keyboard.MouseMoveDown"] },
+          "to": "Actions.DeltaPitch",
+          "when": "Application.CaptureMouse",
+          "filters":
+            [
+                { "type": "scale", "scale": 0.2 }
+            ]
+        },
+
         { "from": { "makeAxis" : ["Keyboard.MouseMoveUp", "Keyboard.MouseMoveDown"] },
           "when": ["Application.CameraLookAt", "Keyboard.RightMouseButton"],
           "to": "Actions.DeltaPitch",

interface/src/Application.cpp

@@ -680,6 +680,7 @@ private:
  *     <tr><td><code>CameraIndependent</code></td><td>number</td><td>number</td><td>The camera is in independent mode.</td></tr>
  *     <tr><td><code>CameraEntity</code></td><td>number</td><td>number</td><td>The camera is in entity mode.</td></tr>
  *     <tr><td><code>InHMD</code></td><td>number</td><td>number</td><td>The user is in HMD mode.</td></tr>
+ *     <tr><td><code>CaptureMouse</code></td><td>number</td><td>number</td><td>The mouse is captured.</td></tr>
  *     <tr><td><code>AdvancedMovement</code></td><td>number</td><td>number</td><td>Advanced movement (walking) controls are
  *       enabled.</td></tr>
  *     <tr><td><code>StrafeEnabled</code></td><td>number</td><td>number</td><td>Strafing is enabled</td></tr>
@@ -715,6 +716,7 @@ static const QString STATE_PLATFORM_ANDROID = "PlatformAndroid";
 static const QString STATE_LEFT_HAND_DOMINANT = "LeftHandDominant";
 static const QString STATE_RIGHT_HAND_DOMINANT = "RightHandDominant";
 static const QString STATE_STRAFE_ENABLED = "StrafeEnabled";
+static const QString STATE_CAMERA_CAPTURE_MOUSE = "CaptureMouse";
 
 // Statically provided display and input plugins
 extern DisplayPluginList getDisplayPlugins();
@@ -918,7 +920,7 @@ bool setupEssentials(int& argc, char** argv, bool runningMarkerExisted) {
     DependencyManager::set<MessagesClient>();
     controller::StateController::setStateVariables({ { STATE_IN_HMD, STATE_CAMERA_FULL_SCREEN_MIRROR,
                     STATE_CAMERA_FIRST_PERSON, STATE_CAMERA_FIRST_PERSON_LOOK_AT, STATE_CAMERA_THIRD_PERSON,
-                    STATE_CAMERA_ENTITY, STATE_CAMERA_INDEPENDENT, STATE_CAMERA_LOOK_AT, STATE_CAMERA_SELFIE,
+                    STATE_CAMERA_ENTITY, STATE_CAMERA_INDEPENDENT, STATE_CAMERA_LOOK_AT, STATE_CAMERA_SELFIE, STATE_CAMERA_CAPTURE_MOUSE,
                     STATE_SNAP_TURN, STATE_ADVANCED_MOVEMENT_CONTROLS, STATE_GROUNDED, STATE_NAV_FOCUSED,
                     STATE_PLATFORM_WINDOWS, STATE_PLATFORM_MAC, STATE_PLATFORM_ANDROID, STATE_LEFT_HAND_DOMINANT, STATE_RIGHT_HAND_DOMINANT, STATE_STRAFE_ENABLED } });
     DependencyManager::set<UserInputMapper>();
@@ -1891,6 +1893,9 @@ Application::Application(int& argc, char** argv, QElapsedTimer& startupTimer, bo
     _applicationStateDevice->setInputVariant(STATE_CAMERA_INDEPENDENT, []() -> float {
         return qApp->getCamera().getMode() == CAMERA_MODE_INDEPENDENT ? 1 : 0;
     });
+    _applicationStateDevice->setInputVariant(STATE_CAMERA_CAPTURE_MOUSE, []() -> float {
+        return qApp->getCamera().getCaptureMouse() ? 1 : 0;
+    });
     _applicationStateDevice->setInputVariant(STATE_SNAP_TURN, []() -> float {
         return qApp->getMyAvatar()->getSnapTurn() ? 1 : 0;
     });
@@ -2406,6 +2411,7 @@ Application::Application(int& argc, char** argv, QElapsedTimer& startupTimer, bo
     updateSystemTabletMode();
 
     connect(&_myCamera, &Camera::modeUpdated, this, &Application::cameraModeChanged);
+    connect(&_myCamera, &Camera::captureMouseUpdated, this, &Application::captureMouseChanged);
 
     DependencyManager::get<PickManager>()->setShouldPickHUDOperator([]() { return DependencyManager::get<HMDScriptingInterface>()->isHMDMode(); });
     DependencyManager::get<PickManager>()->setCalculatePos2DFromHUDOperator([this](const glm::vec3& intersection) {
@@ -5910,6 +5916,18 @@ void Application::cameraModeChanged() {
     cameraMenuChanged();
 }
 
+void Application::captureMouseChanged() {
+    if (_myCamera.getCaptureMouse()) {
+        // we want to grab the mouse here so that no other widgets get events, and also hide the mouse, but these don't work:
+        //_glWidget->grabMouse();
+        //QCursor::setShape(Qt::CursorShape::BlankCursor);
+    } else {
+        // we want to release the mouse here so that other widgets get events, and also show the mouse, but these don't work:
+        //_glWidget->releaseMouse();
+        //QCursor::setShape(Qt::CursorShape::ArrowCursor);
+    }
+}
+
 void Application::changeViewAsNeeded(float boomLength) {
     // Switch between first and third person views as needed
     // This is called when the boom length has changed

interface/src/Application.h

@@ -430,6 +430,7 @@ public slots:
     void cycleCamera();
     void cameraModeChanged();
     void cameraMenuChanged();
+    void captureMouseChanged();
     void toggleOverlays();
     void setOverlaysVisible(bool visible);
     Q_INVOKABLE void centerUI();

libraries/shared/src/shared/Camera.h

@@ -43,6 +43,7 @@ class Camera : public QObject {
     Q_PROPERTY(glm::quat orientation READ getOrientation WRITE setOrientation)
     Q_PROPERTY(QString mode READ getModeString WRITE setModeString NOTIFY modeUpdated)
     Q_PROPERTY(QVariantMap frustum READ getViewFrustum CONSTANT)
+    Q_PROPERTY(bool captureMouse READ getCaptureMouse WRITE setCaptureMouse NOTIFY captureMouseUpdated)
 
 public:
     Camera();
@@ -110,6 +111,20 @@ public slots:
      */
     void setOrientation(const glm::quat& orientation);
 
+    /**jsdoc
+     * Gets the current mouse capture state.
+     * @function Camera.getMouseCapture
+     * @returns {boolean} The current mouse capture state.
+     */
+    bool getCaptureMouse() const { return _captureMouse; }
+
+    /**jsdoc
+     * Sets mouse capture state.
+     * @function Camera.setCaptureMouse
+     * @param {boolean} captureMouse - Whether or not to capture the mouse.
+     */
+    void setCaptureMouse(bool captureMouse) { _captureMouse = captureMouse; }
+
     /**jsdoc
      * Computes a {@link PickRay} based on the current camera configuration and the specified <code>x, y</code> position on the 
      * screen. The {@link PickRay} can be used in functions such as {@link Entities.findRayIntersection} and 
@@ -181,6 +196,20 @@ signals:
      */
     void modeUpdated(const QString& newMode);
 
+    /**jsdoc
+     * Triggered when the camera mouse capture state changes.
+     * @function Camera.captureMouseUpdated
+     * @param {boolean} newCaptureMouse - The new mouse capture state.
+     * @returns {Signal}
+     * @example <caption>Report mouse capture state changes.</caption>
+     * function onCaptureMouseUpdated(newCaptureMouse) {
+     *     print("The mouse capture has changed to " + newCaptureMouse);
+     * }
+     *
+     * Camera.captureMouseUpdated.connect(onCaptureMouseUpdated);
+     */
+    void captureMouseUpdated(bool newCaptureMouse);
+
 private:
     void recompose();
     void decompose();
@@ -194,6 +223,8 @@ private:
     glm::quat _orientation;
     bool _isKeepLookingAt{ false };
     glm::vec3 _lookingAt;
+
+    bool _captureMouse { false };
 };
 
 #endif // hifi_Camera_h