Array Parameters

[Stadtler]

To have the ability to change the number of items for an array that is within a family - an array parameter. The change would be based on the result of a formula.

for example:

The spacing for items of an array can be no less than X and no larger than Y. The total length of all spacings to be Z.

Formula then calculates how many items are needed and this number is assigned to the array parameter. Such a value could also be retrieved from a lookup table.

[luigi]

Other than maybe the lookup table, can't you do this right now? I may be mis-understanding what you are describing, but I often have formulas drive my arrays.

To have the ability to change the number of items for an array that is within a family - an array parameter. The change would be based on the result of a formula.

for example:

The spacing for items of an array can be no less than X and no larger than Y. The total length of all spacings to be Z.

Formula then calculates how many items are needed and this number is assigned to the array parameter. Such a value could also be retrieved from a lookup table.

[clog boy]

You could select the array, then click the line over it (straight under the number of array items) and then Label as you would do with a dimension. If there's a length parameter between the first two items, then you could use all of that in your calculations.

The easiest way would ofcourse be to calculate the amount based on total length and a constant or variable. Furthermore you could use a dummy parameter (integer based on average of maximum and minimum) and recalculate the distance between the first two items. For total Uebercool functionality you could make a new parameter for Length, make it an Instance and assign it to two reference planes so that in your project you'll have grip controls. Grab them - and the element would grow fluently.

Just make sure you use nested families and keep them as relatively simpel as needed, since this approach is a resource hog.


Retrieval from lookup table would be a biggie. You could make the amount of items a shared parameter (linked to a dummy if need be, to recalculate distance between the first two elements?) and then load them in a schedule. It's manual input but hey, so is a lookup table.

[mjdanowski]

I believe this can currently be done via a "Number Parameter" as well as a length dimension between the first and second instance of the array.

[MartinR.167480]

WARNING: In Revit 2008 (maybe others) an integer parameter computed from othe parameters may be wrong. 11/5 = 2.2 and will come out as 2. 14/5 = 2.8 and will come out as 3. Revit "helpfully" rounds integers when computed from real numbers (e.g., lengths). This can often leads to arrays that post an extra element in a family.

To get the correct value subtract 0.499 from the computed value.

P.S., I found this the hard way!