Setting Up in the Real World - Labelling Spot Heights

Series Index - Setting Up in the Real World

Another use for Cells containing text fields (mentioned in Setting Up in the Real World - Labelling Coordinates) is labelling spot heights. As shown in that article, cells can contain text fields that display selected coordinates of the cell origin. A cell that indicates z-height obviously uses the Z coordinate doesn't it? In the 3D model it does, but in a 2D drawing the Y coordinate must be used, Y = up in 2D.

This means that you may need to create multiple versions of cells for 2D and 3D uses.

In the case of 3D a cell like this the selected point is the origin of the triangle:

A prefix has been added in the text field properties, this could also be separate text, any number of fields can be included in a text string.

When the cell is placed in 3D enable the Interactive > Rotate Only setting to enable alignment of 2D cells to AccuDraw planes during placement, if this is not used they will align to the view. Alternatively create the cell in 3D already 'stood up' and use AccuDraw T then rotate it to face in the appropriate direction (one step less is required during placement with this approach).

Note that Text Fields always display coordinates relative to the Global Origin.

If you wish to annotate spot heights in Drawing or Sheet models created by Dynamic Views the graphics are all on the cut plane so any annotation will only pick up the z height from the cut plane. However annotation of actual z-heights, e.g. stair treads or landings, is possible in these model types:

  • Go to Set Reference Presentation for the relevant reference(es) by right-click or via the reference dialog
  • Turn off Drawing Symbols in both Forward and Cut settings

This will display the 3d model instead of the 2d cut symbology

You can then use the Label Coordinate tool to annotate spot heights:

Note the settings can be modified to suit the required label as indicated by this example.

Then reverse the reference presentation settings either manually or by 'Update From Saved View', the cut symbology is restored, the annotation remains:

The font, terminator and other attributes for the Label Coordinate symbol can be modified to your own requirements/standards as described in Annotation - SS5 and New Label Coordinates Tool.

An appropriate 2D cell could also be used in this process instead of the Label Coordinate tool.

Sample files are available at Example Cells Using Text Fields to Display Coordinates 2022.

Another example where the Text Field cell could be used is section or elevation annotation. Note that AECOsim Building Designer does have a 'Place Spot Elevation' tool, but this is just a dumb label (I think it pre-dates the introduction of text fields) where the text has to be manually entered.

Having cut a section with the Place Section Callout tool creating both Drawing and Sheet Models the cell 'Section Level Marker Datum +' ' Shows Y coordinate relative to global origin' can be used in either Drawing or Sheet Model to label heights. This cell displays the Y coordinate of the cell origin (the Drawing and Sheet Models are both 2D presentations).

Because the Drawing Model is spatially correct, here you can see the placed cells match up with the Grid System Level markers:

In a Sheet Model the cell will pick up its coordinates from the 1:1 paper so additional steps are required.

The cell outlined in red is placed in the Sheet Model and shows the accurate Y coordinate figure relative to the lower left corner of the A0 sheet.

The 'm' label is also misleading, this is due to the way that cell is formatted. I deliberately set the text field to label with Master Units and the Master Units to 'm' instead of '(Use Active Settings)' as I wanted the datum points shown in m.

The cells outlined in green on the left were placed in the Drawing Model as illustrated above. The Cell outlined in green on the right was placed while in the Sheet Model but with the Drawing Model reference activated, so is correctly relative to the Drawing Model's origin. Once the Drawing Model is activated that models' global origin is used:

This is not like dimensioning where the dimensions pick up from the model elements. The text fields are simply using the position of the cell itself with no relationship to the element being snapped to.

  • Hi Mark, interesting topic!

    When I read the title of the blog post I was thinking about spot heights in a plan view. Though the elevation/section views as you described are also very interesting.

    As far as I can think of for a plan view this would only work in the 3D model, right? Because there is no Z coordinate in the 2D drawing so it would not be possible to put that in a text field.

    Is there a way however to place spot height annotation - as well as spot slope annotation, preferably with a slope arrow - on a plan view? In my imagination it must be possible somehow, because with display styles and "Thematic display" it is possible both for 'Height' and 'Slope' to be displayed, even in a 2D drawing model, right?