Define Dimension Lines for Precast Shop Drawings

Learn how to define family reference lines, subcategories and shared parameters to control dimensions in your precast shop drawings.

About Defining Dimension Lines

The reference lines for shop drawing dimensioning are standard model lines that have a special subcategory defined for them. This subcategory de­fines in which views (relative to the family orientation) these lines are used to create dimensions:

• Dimension_Top View from top

• Dimension_Front View from the front
• Dimension_Side View from the side

Define Subcategories

1. Create one or several sub-categories and name them accordingly. See Create Object Style Subcategories.
   Note: In the New Subcategory dialog, Name field, enter a name for your subcategory, using the following naming convention rule: Dimension _ (underscore) Top: "Dimension_Top"
2. Create all the necessary subcategories (e.g. Dimension_Top, Dimension_Front, Dimension_Side) and exit the Object Styles dialog.
3. In the New Subcategory dialog, Subcategory of field, select Structural Connections.
4. Create a family that you will use later in your project.
5. In the Properties palette Identity Data Subcategory, assign the model lines to the new subcategories you created.

Define the Visibility Parameter

The line should normally be invisible, so that it does not change the appearance of the model. You can control this by attributing a shared parameter to the line that makes it invisible in the model.

To make the line visible:

1. Associate a shared parameter to the Visible property of the line. In the Properties palette, click the button next to the Visible parameter to open the Associate Family Parameter dialog.
2. If already on the list, select the Visibility dimension line parameter. If the parameter is not on the list:
   1. Click (New Parameter).
   2. In the Parameter Properties dialog, select Shared parameter under Parameter Type.
   3. Click the Select button.
   4. In the Shared Parameters dialog, click the Edit button.
   5. In the Edit Shared Parameters dialog, click the Browse button to navigate to the Shared Parameters file (e.g. C:\ProgramData\Autodesk\RVT 2023 Release\Libraries\[LANGUAGE]\Structural Precast).
   6. Once the Parameters list is populated, click OK.
   7. In the Shared Parameters dialog, select Visibility dimension line and click OK.
   8. In the Parameter Properties dialog, select Instance under Parameter Data and click OK to close the dialog.

3. In the Modify tab Properties panel, click (Family Types).

4. In the Family Types dialog, in the Value column, clear the checkbox for Visibility dimension line (default).
5. Click OK to apply the settings and exit the Family Types dialog.

Note: If you define the dimension line in a nested family, you need to pass this parameter up to the main family - the family that is loaded into the Revit project.

In a shop drawing view, a dimension line is dimensioned only if the plane of the view is parallel to the plane of the part where the dimension line is used - based on the subcategory name of the dimension line. If that is the case, the line is dimensioned as follows:

• The line is in a plane parallel to the plane of the part where the line should be dimensioned - the line is dimensioned in the direction of the line, if the line is parallel to a main axis of the view on the shop drawing. Each line is used once only and it will be dimensioned either horizontally or vertically. If the line is not parallel to one of the main axes, it will not be dimensioned.
• The line is in a plane orthogonal to the plane of the part where it should be dimensioned - the line will always be dimensioned vertically and horizontally, regardless of the fact that it is not parallel to any of the axes in the view.