The Map Editor

This chapter explains the usage of the COVISE Map Editor, how to work with modules, connect module ports to a map and modify module parameters. After reading this chapter you should be able to visualize your data within COVISE.

The graphical user interface is based on the Qt software from Trolltech . After typing covise on a command line or clicking on a covise icon the Map Editor top level window appears.


The windows layout consists of the following main parts:

  1. the Menubar
  2. the Toolbar
  3. the Visual Programming Areawhich is used to show and edit a module network.
  4. the Data Object Browserwhich contains a list of all available modules on a certain host sorted by categories.
  5. the statusline which shows the number of existing messages from the Controller, modules and other COVISE parts and the last content.
  6. the Chat Linewhich is only visible in collaborative working mode


The Menubar contains all items to

File Menu

Most of the items in the File entry of the Menubar are also avaible in the Toolbar:


Execution Menu

When executing a module network one module icon after the other shows a colored frame which indicated that it operates. A module network can be executed once or repeatedly.


The settings are:


This menu entry contains items for a distributed or collaborative working mode

Additional hosts can be introduced at nearly every time during a COVISE session. It serves to use specific resources like supercomputers or fileservers. The first three items of this menu entry are also available in the Toolbar.


The timeout value specifies how many seconds a process will wait to be contacted by a new process it initiated (e.g the Controller waiting for module). This parameter should be increased if the network is slow.

The execeution mode specifies the command which should be used to start the CRB on the remote computer. Possible execution modes are:

When the remote host is successfully added, the remote username and hostname will appear in the ist of hostnames of the Module Browser with a different color.

Module Menu

Module icons in the Visual Programming Area can be manipulated.


The settings are:

Tools Menu

The items of this menu entry open additional window parts.


The settings are:

Available Help


A tooltip is a small piece of text that appears when the cursor is hover a widget for a certain period of time. Tooltips are available for all icons of the Toolbar, the main buttons in the Module Parameter window, the Control Panel, the Settings and some other relevant items.

What's this ?

If more information is needed about a certain region of the Map Editor the "What's This ?" mode is ideal. The mode can be entered when the ? icon in the Toolbar is clicked. The cursor changes to *** . Click a region to obtain more information.

Online help

COVISE opens a seperate help window when the item "Help" in the menubar is pressed. This window is also available with Shift+F1.


The following help topics are available.


The Toolbar contains

  1. icons for the most important actions
  2. frequently used modules

Toolbar Icons

toolicons.png or toolbar2.png

These icons have the same behaviour as the items in the Menubar. The toolbar is dockable that means it can be disconnect from the main window and show the content in an own separate window. A short decription of the icons is given in the following list:

  1. Load a new map into COVISE
  2. Save the current map. Overrides a given map name !!
  3. Execute the module network
  4. The "What's This" help cursor
  5. Request the master state (only enabled if you are in slave mode)


Favourites are often used modules. They can be used in the same manner as modules listed in the Module Browser.


  1. The module name can be dragged into the Visual Programming Area.
  2. New favourite can be addeed to the list by dragging a module from the Module Browser to the favourite list. The drop point marks the position in the list.
  3. A favourite can be removed from the list by dragging a favourite name to the Module Browser window.
  4. The list can be sorted by double clicking on a favourite name.

Module Browser

This area contains a hierarchy (tree) displaying the hostnames, category names and module names. When COVISE is started in single user mode only the name of the local host is shown in the tree.


Modules running on a host appear in the same color as the host name in the list. The subdirectories of ~/covise/ARCHSUFFIX/bin will be used as names of the categories. The files in each category subdirectory are displayed as module names.

Short description of the category and the modules are shown as tooltips. Clicking on a host with the right mouse button opens a popup menu with one single entry Delete Host. Clicking on this item with the left mouse button will remove all modules running on that host and a possible remote user interface. Clicking on a category or module with the right mouse button will open the COVISE help system.

The modules shown for each category depend on the choosen modules in former sessions. To simplify the view only modules which have been used before are shown. All other modules are hidden behind the item More... Clicking on this item will show all available modules in this category.

The special category All contains all available modules in alphabetic order and the corresponding category.


Interacting with the Module Browser is done in the following ways:

  1. Clicking on the +/- sign open/close the corresponding category.
  2. Double clicking on a category name opens this specific category and closes all others.
  3. Clicking into the Visual Programming Area and typing / allows to enter a search string. All categories containing this string in the module name will be highlighted. Icons of these module in the Visual Programming Area will also be highlighted.

To start a module its module name has to be dragged to the canvas. A Module Icon on the canvas indicates, that the respective program representing the module has been started and waits for its execution.

Visual Programming Area (Canvas)

This canvas is used to show the module network. Module icons, that can be moves around, and connection lines between module ports can be seen. Executing a map visualizes the data using the Renderer window. The execution of modules is indicated by highlighting the icon boundaries of currently executing modules. This red highlighting sweeps sequential through the processing pipeline.


Module Icon

The above picture shows a typically module icon. Each module is represented by such an icon. A module icon has


A tooltip shows port information like name, description and available datatypes. If a data object exists (after the pipline has already been executed) information about the created data type are shown, otherwise the text No data object appears.

Module Actions

A popup menu is shown, when the right mouse button is pressed on a module icon. This allows to perform the following module actions:


How to move a module

Hold down the left mouse button on the module icon. The mouse pointer changes and you can move the icon to a new position. The icon will follow the mouse pointer. Then release the mouse button. If the icons have connection lines to other ports, these lines will be repositioned too.

How to group modules


YThere are two methods for grouping module icons on the canvas:

  1. Specific Selection

    Press the SHIFT-Key and click on a module icon. The icon background changes to the user selected highlight color . Doing the same action on an already selected module icon deselects it.

  2. Selection via a rubberband

    Click on an empty part of the canvas to determine the startpoint of the rubberband rectangle. Keep the mouse button pressed and move the mouse so that module icons which should be grouped together lie completely inside the rectangle. After the mouse button is released each of the icons inside the group become red (the current hihglight color). Clicking on an empty part of the canvas ungroups the group.

  3. CTRL+A selects all modules on the canvas.

Connecting Ports

To build a module network you must connect the output ports of modules to the input ports of follow-on modules. Input and output ports of modules are color coded buttons according to the Module Icon. A blue input port represents a data port, that has to be connected before a proper execution is possible. A green input port represents an optional port that can have a connection. Not all blue output ports need to be connected.

There are two methods for connecting ports:

  1. Using the left mouse button

    The easiest way to establish proper connections without looking into the detailed descriptions of the module ports is by clicking with the left mouse button on the port of a module. This leads to highlighting and/or blowing up of matching module ports, which offer the appropriate data type.


    Move the cursor to a heighlighted port. You now see a rubber line following your mouse cursor.


    The connection is established when the mouse button is released within a port. You can also directly click onto the the desired highlighted port. In the same way you have to connect all modules of a map.


  2. Using the right mouse button

    Pressing/clicking on a port with the right mouse button pops up a menu that shows matching ports. Selecting an item will create a connection line. This method is best when the network map has a lot a modules some of them outside the visible range.


Move the mouse over a connection line. The line will be highlighted if the cursor is exactly on the line. Delete the connection line by a double click or via a popupmenu that is shown when using the right mouse button on a line.

Module Parameter

Every module can present a detailed view of its input and output data objects as well as its parameters. Click with the left mouse button on the book icon of a module. A new window appears on top of the MapEditor window (default) or a new dockable widget becomes visible inside the main Map Editor window. The positions depends on your Settings parameter.


Each parameter is represented by

Control Panel

The purpose of the Control Panel is the collection of graphical interactors which typically represent often used and changed parameters.


Widgets corresponding to the parameter types are used for the layout of interactor. Interactors in the ControlPanel allow the manipulation of parameters at every time without the need to pop up the Module Parameter. By clicking the toggle button in the Module Parameter window an interactor is generated. Its representation then appears in the Control Panel.

Changes made via interactors in the Control Panel are updated in the corresponding parameter value fields of the Module Parameter window. This works also vice versa.

Available interactors for each parameter are shown in the following list.

Data Objects, Data Viewer

Data objects are created when a map is executed. The names of the data objects are generated generically, after the map was executed once. After a new execution the list is updated with the new names.

If you select a data object in the Data Object Browser more information is shown in the Data Viewer on the right side of the Map Editor


Be careful if the data field is large or the data is located on another host, because this action will be time consuming.

Colormap Editor


The purpose of the colormap editor is to define the ``transfer function'', i. e. the mapping from scalar values to opacity (i. e. inverse transparency) and colour values. The range of your data is mapped to for the purpose of defining colour mappings.

The transfer function is given as a piecewise linear mapping, the small triangles (``interpolation markers'') below the coloured bar in the picture above serve as nodes for linear interpolation. By clicking on an interpolation marker you can select it for manipulation:

The opacity can be modified by the self-named slider and input fields. For changing the colour values, there are more possibilities:

The resulting colour map is displayed in the large bar near the bottom.

For speeding up, chose from predefined colour maps available in the configuration file with the ``Available Colormaps'' combo box, use the button labelled ``Save in ConfigFile'' for adding such a colour map.



Settings are used for the appearance and behaviour of the Map Editor. These parameters are stored in the file mapqt.xml which resides in $HOME/.covise and in $APPDATA\covise respectively.

Message Area


This scrollable text output window shows messages with different colors

Messages are sent from modules during their execution, the Controller and the request broker CRB.

Chat Line

This editable text field is used for sending information to other partners joining a COVISE session. As expected, the chat line is shown for two or more partners only.

Martin Aumueller 2016-03-23