Edit Family

Select the siding profile and click on Edit Family.

Edit nested family

Find in the Project Browser and Edit the nested family - Siding profile.

Modify the profile

To change the profile, start drawing lines. Use the split element and trim or delete command to achieve your desired profile.

Note: make sure the lines form a closed contour without intersecting lines. Hover over the contour and click Tab. It will highlight the profile.

Modify the parameters

Once lines are in place, set up all the necessary parameters. Under the Family Types, you will see all the parameters.

Let's start with the parameters Last and First. These parameters define how the siding family will act if it needs to be cut along its length.

When the parameter Last is true, the top of the profile has to become horizontal.

When the parameter First is true, the bottom of the profile has to become horizontal.

Parameters CH_D and CH_DS are the ones that modify the lines that are at the top and bottom of the profile if Last or First is true.

Now that our geometry is modified, we must also alter those parameters, e.g., the Sample siding profile family has three lines. The customized siding profile family has five lines. That is why in the CH_D and CH_DS formulas, d/3 has to become d/5.

Correct the parameters according to your geometry.

  • Dimension CH_D has to become "=if(or(Last True, Lengthen), d/5, d/3)"
  • Dimension CH_DS has to become "=if(First, d/5, d/3)

Now we can edit witness lines according to the new geometry. Ensure lines are equal and the dimension has the "d" value.

Note: increase the "d" value before editing witness lines.

Create Instance Parameters

We need additional Instance parameters as we now have additional lines at the top and bottom of the profile. Let's create a new instance parameter CH_D0 and assign it to one of the lines that should be vertical when the profile is not cut along its length. This parameter sets the line length equal to d/5 if Last is true and 0 if not (line becomes vertical).

Create an Instance parameter that works with the formula - if(or(Last True, Lengthen), d/5, 0) and assign it as shown below.

Note: In this situation, dimensions must be set to the endpoints of lines. Otherwise, the profile will be over-constrained. Use Tab to select endpoints.

Assign the CH_D instance parameter for the other three horizontal lines, as shown below.

Add an instance parameter as shown below (CH_L4) to regulate the height of additional lines created. Add formula to that parameter - if(or(Last True, Lengthen), 0, 15) to change the height to zero if the parameter Last is True.

Apply a similar procedure to the bottom of the profile. Create additional Instance parameters that would make the bottom of the profile horizontal if First is true. E.g., CH_L5 will align the lines to the reference plane (length is 0) if First is true and will have a length of 15 (you can change this length according to your needs) if not. The parameter CH_DS0 will have a horizontal length of d/5 (as we mentioned before, now we do have five lines, so we divide the d value of those five lines) if First is true, and it would become vertical (length equals 0) if not.

Create Instance parameters with formulas:

  • Instance parameter with formula =if(First, 0, 15)
  • Instance parameter with formula =if(First, d/5, 0)

Add the "d" constraint at the bottom of the profile. 

Note: if the profile consists of more than two main parallel lines, it is recommended to create ref. planes, assign "d" constraint between them and attach the lines to those ref. planes. Otherwise, assigning the "d" constrain directly to those lines is enough.

According to the new geometry, change CH_L3 and Min Spacing formulas instead of "d/2" to "d/3".

Constrain the cut-out

Constrain the cut-out. Otherwise, the profile won't make a closed contour when Last or First is true. After this step, make sure to test the family to see if it works properly when:

  • Last is true
  • Spacing is lower than Standard Spacing
  • First is true

With all these parameters set, the profile should act as shown below.

Note: Ensure that the cut-out won't intersect with lines at the bottom of a profile and doesn't create a double contour loop. 

Once all these steps are done, and the family works correctly, load it to the 3D Siding family and then to the Revit project.