Overlay objects are special versions of other objects that are used for graphical display in a simulation model. Unlike other display objects, the position of overlay objects is referenced to the corner of a view window, and so the object does not move when the View is panned or zoomed. These objects are useful for labelling View windows or displaying the model name and company logos. Examples of overlay objects are the default Title and Clock that are provided automatically when a new model is opened.
There are three types of overlay objects, each corresponding to a different graphical object type. The relationship between each overlay object, its parent object type, and its usage is summarized in the following table.
Overlay Object and Usage Summary
Overlay Object |
Parent Object |
Usage |
OverlayImage |
DisplayEntity |
Static image (Logos, other graphics) |
OverlayText |
Text |
Static or dynamic text (Model name, states, rates) |
OverlayClock |
Text |
Current time in the simulation model. |
Apart from graphics inputs, each type of overlay object has the same keywords as its parent object. The graphics inputs for overlay objects are shown in the following table.
Overlay Objects Graphics Inputs
Keyword |
Description |
ScreenPosition |
A list of two numbers specifying the spacing, in pixels, between the left and top corner of the View window and the object. |
AlignRight |
If TRUE, the horizontal alignment is referenced to the right side of the View window instead of the left. |
AlignBottom |
If TRUE, the vertical alignment is referenced to the bottom side of the View window instead of the top. |