Editing Existing Lighting Families

[Anonymous]

I'm attempting to use an existing BIM model to model pole lighting, however I do not see a field in which I can change the pole height directly. I've went into the properties of the family and see 3 fields labeled "zz height", however upon attempting to edit one I get the "constraints not satisfied error.

What would be the best approach in getting this to work? I've attached the family file I'm attempting to use. 

[MostafaElashmawy · Accepted solution]

The family you shared have specific types with specific heights. The height parameters are controlled by formulas based on the type selected.

To see which height controls what, go to front or back view and type "VG" then make sure that dimensions are turned on.

the main parameters controlling the height is two parameter called UR28 and UR 20, when the family is UR 28 it shows certain heights while if it's UR20 it shows other heights.

you can change all of that manually by deleting the formulas from the parameters and enter specific values.

[barthbradley]

All Height Combinations are driven by Formulas and Types. In Order to change the heights, you need to modify the Formulas.    

You could add another parameter (e.g. "UR") to add more height by doing this:

[Anonymous]

Following question (and thanks for your solution @MostafaElashmawy😞

I'm attempting to make the change using that suggestion, however due to the geometry it results in a "constraints not met" error message. It seems by modifying the heights, 

I'm attempting to keep the dimensions of the head the same, while only modifying the zzheight "3" from the reference plane. I think I have to add a reference plane somewhere at the head of the fixture and then maybe lock constraint. Is this the correct way of thinking? If not, what would be the best way to go about only trying to change the pole height and not modifying anything else?

I'm still getting acquainted with trying to understand constraint placements. 

[barthbradley · Accepted solution]

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@Anonymous wrote:

what would be the best way to go about only trying to change the pole height and not modifying anything else?

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by doing exactly what I suggested.  Change or add to the conditional formula that controls Height.

FWIW: Conditional statement uses this structure:

IF (<condition>, <result-if-true>, <result-if-false>)

[MostafaElashmawy]

If it's only about height, you don't need to move the reference line.

Save this family as new family to avoid disturbing the original family, then remove the formula of Height 1 then type whatever value you want.

Do the same for other formulas.

check below video.

https://knowledge.autodesk.com/community/screencast/d6f15a0c-dd9c-42a6-9607-e8ce0f8be011

[martijn_pater]

nvm^^ If you want to keep the proportions but scale up/down you could also do what Bradley mentioned but with multiplier (ie. x1,5), that would work up to a point... you could limit the input values with an IF formula again.

[Anonymous]

my apologies @barthbradley . This was probably added when I was typing the follow up question. Thanks!