Graphics Programs Reference
In-Depth Information
Setting the Behavior of reference planes and Lines
When you place a new reference plane or line or select one already in your family, you will
notice a property in the Properties palette called
Is Reference
. This setting is an important factor
in how the family will behave when it is placed in a project. It affects how you can dimension or
align to the family as follows:
◆
Not A Reference—The reference will be used only to control geometry in the Family
Editor.
◆
Weak Reference—The reference can be accessed for measurement in the project environ-
ment only by pressing the Tab key on the keyboard.
◆
Strong Reference—The reference has the highest priority for dimensions and alignment.
Temporary dimensions are displayed at the strong reference data.
In the Family Editor, reference planes also have other available values for the Is Reference
property including Top, Back, Bottom, Left, Right, and Front. These values are all strong
references and are provided to help you better organize your family geometry.
You will also notice that symbolic lines have a property called Reference with settings
identical to those for the Is Reference property of reference planes and reference lines. We
recommend that you treat symbolic lines with the same care as the datum objects.
We recommend you use the strong and weak references sparingly throughout your family.
The default setting for the Is Reference property is Weak Reference; therefore, there could be
a large number of possibilities for measurement within
every component
in your project. For
every strong or weak reference, Revit must analyze the reference when you are annotating or
designing.
Setting the Insertion point
After you've chosen an appropriate family template, the rest is pretty flexible. If you make any
mistakes, you'll probably be able to recover most if not all of your work to correct the problem.
But some considerations should come before others, which is why we believe that the insertion
point is the next most critical criterion on your list for family creation.
First, the insertion point determines the location about which the family will geometrically
flex. But second (and often more important), the insertion point is the point of reference when
two family components are exchanged. This is critical if the “design” family that you've used as
a placeholder is being swapped out for something more specific at a later date. If the insertion
points are not established similarly between families, the location of the new family will not
agree with the location of the old one.
For example, most of the tables in the default Revit furniture library define the insertion
point at the center of the geometry, as shown in Figure 14.16. If you place one table family
in your project and then later decide to swap it for a different table family, there should be
minimal disruption to the layout of other furniture in your design. The new family will appear
in roughly the same spot as the originally placed family. Now what happens if you were to
download a table family from a web-based content provider? Will that table also follow the
same convention for the location of the insertion point? This concern illustrates the importance
of following published guidelines or standards for content creation.
Certification
Objective
