====== Focus and Synchronize Views ======

===== Concepts =====

The Focus and Synchronize Views functions allow views to sync up to the focus position of other views.  
  * A focus position can be derived from a view, based on render mode and state.
  * A focus position can also be applied to a view.  How this happens, also differs per render mode.

===== Focus Action =====

The "Focus" View Action lets all other views focus on the data that is visible in the focused view.  A focus position is derived from the focused view and then applied to all other view in the workspace.

The Focus action can be enabled in [[2310:viewer:core:settings]].

===== Synchronize Views =====

Views can also be configured to automatically synchronize to the active view.  In the [[2310:viewer:core:settings|Navigation Settings]] 3 synchronization types are available : 
  * Synchronize Views : Non-reference views sync with interactions on other non-reference views.
  * Synchronize Views From Reference : Non-reference views sync with interactions on the reference view.
  * Synchronize Reference From Views : The reference view syncs with interactions on non-reference views.

When any of these settings are enabled, synchronization occurs automatically.  Some views may synchronize in real-time, while others may react with a small delay because updating in real-time is not feasible. 

===== Derive a Focus Position =====

^ View Mode ^ Origin  ^
| 2D Reference | Get 2D center position. |
| 3D | Get 3D center intersection with visible data |
| Spherical Photo | Get 3D photo position |
| Planar Photo | - Ground footprint possible : Get 3D center intersection with visible data, DEM or plane at ground height.\\ - No ground footprint : Get 3D photo position |

When possible, a view position is also retained, so the pan/tilt angle can be retained when applying the focus position.

===== Apply a Focus Position =====

If the focus position is 2D, the focus position is made into a 3D position by inserting with the workspace terrain model or the ground plane.

^ View Mode ^ Technique  ^
| 2D Reference | Move to focus position (x,y) | 
| 3D | Move to a position that looks at the focus position from a distance (max 100 meters).\\ Copy the pan/tilt angles when possible. |
| Spherical Photo | Open the best photo for this position and focus\\ - A 3D focus position will change pan/tilt.\\ - A 2D position will only change pan |
| Planar Photo | Open the best photo for this position and focus. |

See [[2310:viewer:core:update_view]] for more information on photo search.

===== Exceptions =====

There are some cases where view synchronization is not just deriving a focus position and applying it. 

==== 3D to 3D ====

In this case, the target 3D view will mimic the source view.

==== Spherical Photo to 3D ====

In this case, the 3D view will mimic the source view.

==== 3D to Photo ====

In this case, the centre of the 3D view is used as a focus position for the photo view.