message: Improved persistence of viewer settings
  This changelist makes MaterialX viewer settings "cameraPosition" and "cameraViewAngle" persistent when the user loads a new mesh, providing a more consistent experience when validating materials across multiple meshes.
diff: @@ -585,9 +585,7 @@ void Viewer::createLoadMeshInterface(Widget* parent, const std::string& label)
  _meshRotation = mx::Vector3();
  _meshScale = 1.0f;
  - _cameraPosition = DEFAULT_CAMERA_POSITION;
  _cameraTarget = mx::Vector3();
  - _cameraViewAngle = DEFAULT_CAMERA_VIEW_ANGLE;
  initCamera();
  }
  