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• How to Display Elevation Values Relative to Sea Level

How to Display Elevation Values Relative to Sea Level

In almost all architectural Projects, you need to show elevations relative to Sea Level. For example, you might want to shown heights relative to Sea Level in the terrain surrounding the building, or you might want to show the elevation of certain elements relative to Sea Level. ArchiCAD offers the Reference Levels feature to create Level Dimensions (in Floor Plan Views) and Elevation Dimensions (in Sections/Elevations) that show values relative to Sea Level.

Note that you must use the Gravity feature to achieve these results. This way, when you create Level Dimensions on the surface of Slabs/Roofs/Meshes, it will display the top level of those elements and, more importantly, it will remain associated to these elements so when their elevation values change, the Level Dimensions will continue to display the correct values.

For general information on these features, see:

• Reference Levels Elevation Dimensions and Gravity in ArchiCAD Help.

Displaying Level Dimensions Relative to Sea Level

Consider the following Mesh:

We want to display the elevations of points on its surface relative to Sea Level. As the first step, we need to rename one of the two additional available Reference Levels to Sea Level. Go to Options > Project Preferences > Working Units & Levels.

In the Reference Levels field at the bottom of the dialog box, select 1st Reference Level by clicking on it.

Modify its name to Sea Level.

Select its Elevation value and enter its level relative to the ±0,00 level of your Project. For example, if the ±0,00 level of your Project is at the height of +110,50 m above Sea Level, you would enter -110,50 for value in this field.

The Sea Level Reference Level will move to the lowest position, since its Elevation value is the lowest.

Click OK.

On the Floor Plan, make sure that your Coordinate Box is visible, because the Z height values are displayed there. If it is not displayed, turn it on with the Window > Palettes > Coordinates command.

Click the small right-pointing arrow in the lower right corner of the Coordinate Box to select your Reference Level, and select Sea Level from the list. Notice that the value has changed to “Sea Level” after you changed it in Project Preferences.

Values in the Z coordinate field will now be displayed relative to the value defined for the Sea Level field.

Suppose you want to show some Terrain level values relative to Sea Level. Select the Wall Tool and click the Gravitate to Mesh option of the Gravity button in the Standard Toolbar. Alternatively, you can turn on this option in the Coordinate Box.

Note: the reason you need to use the Wall Tool is because the Gravity option is enabled only when the active Tool creates an element that can gravitate (e.g. a Wall can gravitate, but a Roof cannot).

Place the Level Dimensions over the Mesh. They will display the values of the surface of the Mesh.

With the Level Dimension tool still active, select all Level Dimensions (alternately, select only those Level Dimensions whose values you wish to show relative to Sea Level).

Now, with SHIFT-click, add one Dimension Text to the selection.

Now you can change the settings of the Dimension Texts of all selected Level Dimension, not the settings of the Level Dimensions themselves.

Go to Dimension Text Settings. As you can see, there are 33 Dimension Texts selected and editable.

See also Move or Edit Dimension Text in ArchiCAD Help.

Click the AutoText radio button, and from the drop-down list to its right, select the to Sea Level option. (Do not select the “Sea Level” option.)

The Text Editing field below the AutoText radio button will show the AutoText code for the option you selected. The non-editable Text field below it shows a preview of what will be displayed.

Click OK to accept changes. All your selected Level Dimensions now display values relative to your defined Sea Level.

Note: In the text editing field below the AutoText radio button, you can enter additional Text which will be displayed as typed. For example, you can select the four corner Level Dimensions and type to Sea into the field:

The result will be the following:

Displaying Elevation Dimensions Relative to Sea Level

Like Level Dimensions, Elevation Dimensions can display values relative to Sea Level.

You have an easier job with Elevation Dimensions, because its Settings dialog contains a built-in option for Sea Level display. In a Section/Elevation View, select the Elevation Dimension chain you wish to modify, and go to the Elevation Dimension Settings dialog box.

In the Dimension Origin drop-down list, select the Sea Level option.

Click the OK button to apply the change. Every Dimension Point of the Elevation Dimension Chain now displays the elevation relative to Sea Level.

Note: You can also select individual Dimension Text items of the Dimension Chain, if you want only those items to display the Sea Level values. In that case, you need to use Auto Text in Dimension Text Settings - as with Level Dimensions.

Note: It is a good idea to assign a new pen to changed Dimension Texts, so you can distinguish custom values from default values later on.

Category3dModeling

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