	Applies To
	Product(s):	WaterGEMS, SewerGEMS, CivilStorm, StormCAD, PondPack, SewerCAD, HAMMER, WaterCAD
	Version(s):	08.11.XX.XX and higher
	Environment:	Standalone
	Area:	Modeling

Problem

How can I control the visibility of elements depending on the zoom level? For example turning off element display when zooming out, so that the drawing pane is not crowded with annotations and/or symbols.

Why do some of my elements disappear when I zoom close in or zoom far out in my model?

Solution

The zoom dependent visibility setting controls the display of elements depending on your zoom level. It can be used to cause elements, decorations (such as flow arrows), and annotations to only appear in the drawing pane when the view is within the zoom range specified by the Minimum and Maximum Zoom values. This can help in some situations to prevent "crowding" of these icons at certain zoom levels.

Note that this feature only applies to the Standalone version. It will not be available in other platforms such as AutoCAD, MicroStation, ArcGIS and OpenRoads Designer (SUDA) since element display is controlled by their respective platform.

To enable or disable, follow these steps:

1) Locate the element in question in the Element Symbology manager window and double click on it. This will open the properties dialog for that element as shown below.

2) Change the zoom dependent visibility "Enabled" property as needed. For example "true" means that the zoom in/out limit fields will apply (causing elements to disappear when outside the range). Set to "false" if you do not want to use zoom dependent visibility (to prevent elements from disappearing at certain zoom levels)

Zoom Out Limit: The minimum zoom level, as a percent of the default zoom level used when creating the hydraulic model, at which objects on the layer will appear in the drawing. The current zoom level is displayed in the lower right hand corner of the interface, next to the coordinate display. You can also set the current zoom level as the minimum by right-clicking a layer in the Element Symbology manager and selecting the Set Minimum Zoom command. The zoom out limit is especially important in GIS style symbology because the symbols and text can become very large. (As you zoom out, the Zoom Level as a percent decreases. Once it drops below the zoom out limit, the objects will no longer appear.)

Zoom in Limit: The maximum zoom level, as a percent of the default zoom level used when creating the hydraulic model, at which objects on the layer will appear in the drawing. The current zoom level is displayed in the lower right hand corner of the interface, next to the coordinate display. You can also set the current zoom level as the maximum by right-clicking a layer in the Element Symbology manager and selecting the Set Maximum Zoom command. The zoom in limit is especially important in CAD style symbology because the symbols and text can become very large. (As you zoom in, the Zoom Level as a percent increases. Once it exceeds the zoom in limit, the objects no longer appear.)

Apply to Element: Set to true to apply the zoom minimums and maximums to the symbols in the drawing.

Apply to Decorations: Set to true to apply the zoom minimums and maximums to flow arrows, check valves, and constituent sources in the drawing.

Apply to Annotations: Set to true to apply the zoom minimums and maximums to labels in the drawing.

Background Layer Zoom-dependent Visibility

Starting with version 24.00.02.XX and higher of OpenFlows Water, OpenFlows Sewer and OpenFlows Storm, you can make visibility of background layers (most file types) zoom-dependent. This is related to the Zoom Level that you can find to the lower right of the drawing pane.

If you right-click on an existing background layer, you can select “Set zoom limits.” This will open the zoom limit settings in the Properties grid. You can select the zoom out and zoom in limit. If the Zoom Level for the drawing is outside of the range, the background layer will no longer display.

Using Zoom Dependent Visibility to cause elements to disappear at certain zoom levels

Problem

Solution

Background Layer Zoom-dependent Visibility

See Also