Vessel Class

Figure 1 58 - Sample Vessel Screenshot

The Vessel Operations Class allows real-time visualization of a Vessel in a 3D scene. A vessel may be a ship, ROV, AUV, oil platform, or any other vehicle. Vessel data can be read through the serial port, or played back from a pre-recorded file. The VesselManager application, discussed in Chapter 6: Additional Data Tools, must be run at the same time as Fledermaus and is used to process the incoming Vessel information. To add a Vessel to the current scene, select the Data > Add Vessel menu option. In the Data Set Control area, the Vessel interface will appear as shown in Figure 159. Initially, a yellow cross will be drawn in the scene signifying that a Vessel is present, but not activated.

Vessel Tab

To activate the Vessel, enter the id number of the object (found from the VesselManager) in the Vessel ID text field and press the Activate button. The Status text field should change from "Not Initialized" to "Active" if VesselManager is running correctly. To view the VesselManager at any time, click the Show VesselManager button on the right side of the interface. Once activated, the Vessel will appear as a small, white vehicle shown in Figure 158.

As data is read by the VesselManager, the position and orientation of the Vessel will change in real-time. By default, the Fledermaus Main Visualization Window does not continually update so that even though the Vessel is moving, the results will not be shown on the screen. To force the display to continually update, select the Rendering > Interactive menu option. To stop updating the screen, select another option from the Rendering menu. The current geographic location of the Vessel is always displayed in the Location text field.

Each vessel has a single point where the position is recorded, which is called a tracked location (this may be a GPS sensor, or some other device). Usually a Vessel will have a single tracked location; however, if multiple tracked locations exist on the same object, click the Advanced… button to view the Advanced Setup dialog as discussed in section 1.10.4. By default, the tracked location is assumed to be at the center of the object. If this is not the case, use the Advanced Setup dialog to change the tracked location position.

A number of options exist for controlling the shape of the Vessel object in the 3D scene. The Model Type drop-down list can be used to select from three different built models: the Basic ROV, a Cube, or a Cylinder. If the Custom type is selected from the list, a custom model can be loaded by clicking on the Load Custom Model button. The custom model being loaded must be a model that was imported using File > Import > Import Model, and then saved as an SD object. Note that when saving a model as an SD object, the model should be facing the positive x-axis (this can be changed using the Transform Vertices button in the Solid Model interface).

The width, height, and depth of the Vessel can be specified in the Size text field. All measurements are given in the units of the scene. Click the Scale button, enter a value in the resulting dialog, and press Enter to uniformly scale the Vessel by that value. For example, if the size was '10.00 10.00 6.00', clicking the Scale button and entering '2.0' into the textfield and pressing Enter would cause the size to become '20.00 20.00 12.00'. To change the color of the Vessel, press the Change Color button and select a color using the standard color selection dialog. Note that the vertical exaggeration of the scene should be set to 1 when comparing distances between the model and the scene.

In the display group, click the Show VesselManager to display the VesselManager application which is used to configure the incoming vessel information. While visualizing the scene, having multiple views of the Vessel can be quite useful. To display an additional view, click the Show View button. This button opens another window that is, by default, constantly focused on the Vessel. To change the how the view is displayed, click the Options… button (see Section 1.10.6 for more information). Again, the display will not continually update unless in Interactive Rendering mode. A monitoring dialog can be displayed by clicking the Show Monitor dialog. This dialog displays important information about the Vessel and is discussed in Section 1.10.5.

Vessel Distances Tab

The Vessel Operations Class allows monitoring the distance between a point on the Vessel and any point in the scene. Each distance monitor is displayed as a row in a table on the Distances tab. Click the Add Distance Monitor to add a new distance monitor to the bottom of the list, or select a row and click the Remove Distance Monitor button to delete a monitor.

Each distance monitor by default measures from the center of the Vessel to another point in the scene. To measure from another point on the Vessel instead of the center, enter an offset in the Local Offset column in the units of the data. For example, if an arm of an ROV is located 3 meters to the right, 2 meters forward, and 1 meter up from the center of the vessel, enter a Local Offset of "3 2 1" to measure from that point.
The point in the scene that the distance monitor measures to changes depending upon the value of the Distance Type column:
Pick Point – Measures to the current pick point in the 3D scene. Select a new pick point by entering Select mode in the main display and then clicking a point in the scene. The current pick point location will be displayed in the Target Location column.
Object – Measures to the center of another object in the scene. Choose the other object using the Target Object drop-down list. To measure to another point on the target object instead of the center, enter an offset in the Target Offset column (as you would in the Local Offset column).
Line Object – Measures the minimum distance from a point to a 3D lines object. Select a lines object in the Target Object drop-down list to measure to that object. This option is useful if a 3D lines object exists that indicates the shoreline of a river or ocean, then a distance monitor of this type can indicate how close the vehicle is to the shore.
Fixed Point – Measures to a fixed point in the scene. Enter the coordinates of the target point in the Target Location column.
Vertical – Measures the distance vertically from the Vessel to the sea floor.
Line Object (+/-) – Similar to the Line Object distance monitor, except displays a positive distance if the vessel is to the right of the line or a negative distance if the vessel is to the left of the line. This monitor is useful to measure the deviation of a vessel from a planned path.
If the Visible toggle is turned on for a distance monitor, a line will be drawn in the scene from the point on the Vessel to the target point. The color of this line can be changed by clicking the rectangle in the Color column and selecting a new color. The line width can be changed by entering a new value in the Line Width column. On most of the distance monitor lines in the 3D scene, three numbers will be displayed: the compass bearing in degrees from the Vessel to the point, the elevation angle to the point, and the distance in meters to the point. Some distance monitor types only display the distance in meters. The distance for each distance monitor is also displayed in the Distance column, as well as in the Monitor dialog (see Section 1.10.5).
If a non-zero value is entered in the Warning Distance column, then the distance line in the 3D scene will be displayed as a bold red line if the measured distance falls below the warning distance. The distance will also be displayed in a red font in the Monitor dialog. Use this option to warn if a vessel gets too close to another object in the scene.
Clicking the Load Points of Interest button allows easily setting up a number of Fixed Point distance monitors to points in the 3D scene. Click the button and select an XYZ file containing the list of points to measure to, and the distance monitors will be automatically created.

Vessel Tools Tab

Vessel Advanced Setup Dialog

The Advanced Setup dialog is used to configure options for the tracked locations (or sensors) on a Vessel, and is show in Figure 162. Display this dialog by clicking the Advanced button in the Vessel Setup group.
Each tracked location is displayed as a row in the main table of the dialog. Enter an Id number for the tracked location that corresponds to the number setup in VesselManager. Clicking the Active toggle will activate or deactivate that sensor. The current position of the tracked location will be displayed in the Location column when in Interactive rendering mode.
By default, the tracked location is assumed to be at the center of the object. If the tracked location is not at the center, enter an offset in the Offset column. The units for the offset are in the units of the scene and indicate the amount right, forward, and up from the center of the object.
To display the tracked location in the 3D scene, enable the Visible toggle. The location will be drawn as a diamond and the color can be changed by clicking on the Color column and selecting a new color.
Usually, a Vessel will only have one tracked location; however, some Vessels may have multiple tracked locations (for example, an oil rig might have a tracked location on each of its pylons). Add a tracked location to the bottom of the list by clicking on the Add Tracked Location button, or remove a tracked location by clicking on a row in the table and clicking the Remove Tracked Location button. Note that each tracked location should have a separate Id number and a separate Offset. The first tracked location is used for the position of the vessel, but the other tracked locations are useful for showing the Vessel prediction.

Vessel Monitor Dialog

Vessel Display Options Dialog

Vessel Advanced Profile Dialog

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