OrcaFlex has a number of settings that can be customised to suit the way that you work. The majority of settings can be adjusted on the preferences form, which is accessed from the Tools | Preferences menu item.

3D view

Minimum mouse drag distance

Object positions are not updated until the mouse has been dragged at least this distance (in pixels). This prevents accidental changes to object positions. To make a small movement, drag away and then back again, or edit the coordinate directly in the object's edit data form.

View rotation increment

Each click on a 3D view rotation button increments or decrements the view azimuth or elevation by this amount.

Refresh interval

During a calculation, all 3D view and graph windows are updated at the rate specified. Different refresh intervals can be used for static and dynamic calculations.

Warning: The update frequency of 3D views and graphs can have an impact on calculation time. Be careful not to set the refresh intervals to be too short.

Drawing timeout

This sets the maximum amount of time that OrcaFlex will allow for the following 3D view drawing tasks:

If a drawing task exceeds the permitted time, then that part of the 3D view will not be displayed. A value of zero means that OrcaFlex will never timeout the drawing.

Background colour

This sets the background colour of all 3D view windows.

Locate object method

Can be either flash object or hide other objects. It determines what method the locate action in the model browser uses.

Normally the default setting of flash object is sufficient to locate objects. However, if the model you are searching for is obscured by other objects then this method may not help you to locate the object. In this case you should use the hide other objects preference.

Axes and labels

A number of different sets of axes and labels can be selected, either on the preferences form or via the view menu, for display on 3D views. These are as follows.

View axes

The view axes show the same directions as the global axes, but are drawn in the top right-hand corner of 3D views, rather than at the global origin.

Scale bar

Determines whether a scale bar is drawn in 3D views.

Note: The scale bar is not drawn for shaded graphics views because perspective would make it meaningless.

Global axes

Determines whether the global axes are drawn, at the model's global origin (0,0,0).

Environment axes

Determines whether the wave, current and wind directions are drawn in the 3D view. When multiple wave trains are present, the first wave train is the primary one, and its direction is drawn using the sea surface pen; the remaining wave train directions are all drawn in the secondary wave direction pen colour.

Local axes

Determines whether the local axes for vessels, buoys, line connections, shapes and constraints are shown. Drawing the local axes on the 3D view helps you check the orientations of these objects.

Note: Local axes are not drawn for shaded graphics views.

Node axes

Determines whether axes for individual line nodes and turbine blade nodes are shown.


Determines whether indicator marks are drawn at the origins of vessels and 6D buoys.

Note: Origins are not drawn for shaded graphics views.

Name labels

Determines whether text labels are drawn to identify each object in the model. The size of the text can be controlled by the label scale preference.

Note: Text labels are not drawn for shaded graphics views.


Determines whether symbols are drawn to represent connections.

Out-of-balance forces

If selected, then in the static analysis (not during the simulation) there are extra lines drawn on the 3D view, representing the out-of-balance force acting on each vessel and buoy. This preference is sometimes useful for static analysis, since it enables you to see how far a buoy or vessel is from being in equilibrium.

The force is drawn as a line, starting at the force's effective point of application, the length of which represents the magnitude of the force. The scaling is piecewise linear and based on the view size of the 3D view. Lines up to viewsize/2 long mean forces up to 10 force units and lines from viewsize/2 to viewsize mean forces from 10 to 1000 force units.

Note: Out-of-balance forces are not drawn for shaded graphics views.

Label scale

Determines the size of name labels and label shape text. A value of 100% gives the default size.


The video preferences allow you to control the compression algorithm used to export video. The software which performs this compression is called a codec. Because the wire frame and shaded graphics modes produce very different images, they require different types of codec.

Shaded graphics codec

The run-length encoding which works well for wire frame graphics is not suitable for shaded replays, and in fact there is no suitable built-in codec in Windows. We recommend using an MPEG-4 codec, many of which are available. In our experience the freely available (licensed under the GPL) XVID codec performs very well. The shaded graphics topic has more information about the XVID codec.

You can choose to use other codecs that are installed on your machine. Should you do so then you must also specify the following information:

Wire frame graphics codec

Run-length encoding is the default setting and is usually the best choice. This codec offers good compression rates for OrcaFlex wire frame video. The AVI files produced using this codec can be played on most Windows PCs.

If you choose uncompressed then each frame of the video is stored as an uncompressed bitmap. This means that the AVI file produced can be extremely large.


JPEG compression quality

A value between 1 and 100 that determines the quality of exported JPEG files. Lower values have poorer visual quality, but greater compression (i.e. smaller file size). Higher values have better visual quality, but less compression (i.e. larger file size).

Minimum digits after decimal separator

Controls the formatting of floating point values. OrcaFlex attempts to show at least the specified number of digits after the decimal separator. This may not always be achieved if there are too many digits before the decimal separator, or if engineering notation is used.

Add program/file details to output

If this is checked then external output includes text with details of the program version, file name, file modified time etc.

Monochrome output

If this is checked then external output (clipboard, exported images, printing etc.) is in black and white. This is useful with black and white printers, since otherwise pale colours may be drawn in very light grey and may be hard to see.

Default file types

OrcaFlex outputs files of a wide variety of formats. For example, spreadsheets can be output in Excel, comma-separated or tab-delimited formats. When you save a file, you can select which format to use with the save as type drop-down on the standard file dialog. The default file types preferences allow you to control which file format is first selected when a file dialog opens.


A number of OrcaFlex warning messages can be disabled by checking don't show this message again on the warning message form. Once a message has been disabled, it will not be shown again. These messages can be re-enabled by checking the appropriate box on this page.

Track changes

Output browser group structure when tracking changes

Changes to the browser group structure are not change tracked. Often, the order of objects in the browser does not change, which means that writing this information to the variation YAML text data file would take up a lot of space in a file which might otherwise be quite concise. This preference allows you to choose whether or not to export this information when saving a YAML text data file for a variation model or restart analysis.

Modified data colour

The colour used to highlight tracked changes on data forms.

Potentially ignored data colour

Some model data can potentially be ignored during a restart analysis because it is instead overridden by the inherited state at the end of the parent simulation. One class of potentially ignored data are the position coordinates of model objects; in this case, the default behaviour is for the objects to continue from where they left off in the parent simulation, rather than snap back to whatever position the reset model data would dictate. Often, it is possible to prevent such potentially ignored data from actually being ignored by marking it as changed or otherwise specifying a new value for that data.


Show splash screen

Determines whether OrcaFlex displays its splash screen when it starts up.

Show statics progress window when statics fails

Determines whether the statics progress window is shown automatically when statics calculations fail.

Batch auto save

If this is enabled then simulations run in batch mode are automatically stored to simulation files at the specified regular auto-save interval. This is useful if your computer is prone to failure (for example because of overnight power failures), since the part-run simulation file can be loaded and continued rather than having to re-run the whole simulation from scratch. The auto-save interval should be neither too short, since then OrcaFlex will then waste a lot of time repeatedly storing away the results, nor too long, since then a lot of simulation work will be lost if a failure occurs.