2.7.1 MSharePointer

Figure 2-6 MSharePointer Before and After Connection

This module is an extension of the collaborative pointer module in release 4.0. It can operate in single user mode giving a functionality similar to that of the original module, but the geometric output has changed and up to five color coded pointers may now be generated from a single module. In addition, pointer geometries may be deleted from the scene, and the active pointer can be selected either by using the Color menu widget, or clicking on the required pointer in the scene.

MSharePointer can also be used in collaborative mode and offers all of the single user functionality as well as some collaborative extensions. The picture above shows two views, before and after connection. Connection to the collaborative session is achieved in the same way as for the other COVISA modules, simply pressing the Initiate button. After connection, the standard Group Number and Connection State widgets appear, as well as the new Show Name and Show View Directions widgets. Selecting Show Name puts the usernames, chosen when users connected to the collaborative session, as text in the Render window next to the pointer geometries that they created. Selecting Show View Directions is used to turn on lines that show the viewing direction of collaborators at the moment when they generated a pointer geometry. For each of the pointer geometries, this viewing direction is represented as a line that joins the pointer geometry to the position in 3D space at which the collaborator's camera had been placed when the pointer geometry was made. This feature requires that the camera output from the collaborator's Render module be connected to the MSharePointer module of the collaborator at the time the pointer geometry was made.

In collaborative mode, Pick events are shared between connected instances of this module with the resulting geometric output being displayed in the Render windows in all connected sessions. Assuming all collaborators have the same object visible in their Render modules, then the generated pointer objects will highlight the same visualization objects in all scenes. Having a number of pointers available enables easy comparison of multiple points in the scene.

Figure 2-7 MSharePointer Wired to Render

The MSharePointer module is wired in a loop with the Render module (see Figure 2-7. The output from Render's Pick port is wired into the input port on MSharePointer. The output Pointer geometry port of MSharePointer is wired into Render's Input port. For more information on wiring up collaborative modules see Section 4.3.

You can control the size and colour of your pointer, so as to distinguish it from pointers generated by other collaborators in the session. To generate Pick events, Render must be set into the appropriate mode, see Section 2.7.1.1.

2.7.1.1 Setting the Render Module into an Appropriate Mode for Use with MSharePointer

After wiring the modules together as described previously, there are four steps involved in creating a Pointer in a scene:

Figure 2-8 Changing the Mode of the Render Module

1. Right click in the Render window and select Decoration in the popup menu. This will give you the border shown in Step 2 of Figure 2-8.

2. Select the mouse pointer shaped button at the top right of the new border in the Render window.

3. Select User Pick Mode from the View pulldown menu.

4. Click at the desired location on an object in the scene to attach your pointer at that point.

2.7.2 MShareGraph3D

Figure 2-9 MShareGraph3D Before and After Connection

This example module is an extension to the original Graph3D module. It can be used in single user mode in the same way as the original. Once connected to a collaborative session, using the Initiate button, it can be used collaboratively. This module demonstrates how collaboration can be achieved with a different mechanism to that used by MSharePointer. Rather than sharing the internally generated Geometry, it allows shared control of the module's control panel widgets. When one collaborator changes the value of any of the widgets, this change is passed to the MShareGraph3D modules of all the other collaborators. When using the COVISA Server in its store and foreward mode, the current control widget values are automatically sent to a collaborator who joins late. If the session is using the COVISA Server in pass mode, then the Sync Values button (only visible after connection) can be used to pass the current control widget values to all collaborators to ensure that the values are the same. The data for this module can be shared using an MShareLat module to share the input lattice data. For more information on sharing data in a collaborative session, see Section 4.4

2.7.3 MShareLatToGeom

Figure 2-10 MShareLatToGeom Before and After Connection

This last example is again an extension of an existing module that can be used in either single user or collaborative mode. The module is connected to a session in the same way as any other collaborative module, by pressing the Initiate button. This module implements collaboration differently to both of the two previously described modules. It effectively combines LatToGeom with an MShareLat module. The user can select either a local data source or a remote data source using the Data_Source widget which becomes visible after connection. If a local data source is selected then the module uses the data wired in from its own map, also sending a copy of that data into the collaborative session when it first arrives. If a remote data source is selected, then the module uses the data coming in from the collaborative session. The control panel widgets of each module are completely independent, but can be shared using an MShareParam module. For more information on sharing parameters in a collaborative session, see Section 4.3.