Understanding Report Parameter

[vincent6062]

Dear All, 

I have created reporting parameters that I want to drive another instance parameter. 

But when creating the formula a warning message pops up saying that" a reporting parameter can be used in a formula only if its dimension references are all to host element in the family"

What does that mean? Could this be fixed?

Please see attached for clarification.

Kind regards.

Vincent

[ToanDN]

It means exactly what it says.  You cannot use a reporting parameter to drive another parameter via a formula.  Generally speaking, pairing an adaptive family with formulas isn't a great idea because the two are based on polar opposite principles. 

With that said, there maybe a workaround by turning the middle line to a divided curve with one segment and turn its length to a normal parameter.  It is quite convoluted method and it will take some time to dig it up.

[barthbradley]

By "Host Element", it's referring to the native host element within the template. For example, door and window family templates have a host wall in them. 

[ToanDN]

Looking at your family again, I am wondering why you don't use a roof or floor to create the ramp?

[vincent6062]

Thanks for your response. I usually use a floor to create ramps but I am working on a project where they already have been created using the ramp tool and do not want to redo the whole lot. Plus I use this family to represent the slope of the ramp in plan, 3D and elevation in 3 clicks as I think it is more efficient than creating detail lines in every views etc...

Unless you have a better way of doing it?

[Corsten.Au]

I ll try to explain in simple logic...

Consider you have two parameter ( which you can input manually )

Instance / Type Parameter

A = 5 ( you input these as integer for ex )

B = 10 ( you input these as integer for ex )

C = A x B ( here C is reporting Parameter, output of some interaction between two other flexible/fixed parameter ) )

now further in the project, or family, you cannot use C as any input parameter ( instance )

cause its a " reporting " output of other two parameters...it doesn't have its own identity as such, its dependent

on other factors..

hence if you need C as an input

somewhere else, you can use A x B Again, but not C directly...

Cheers!

[vincent6062]

I have been able to drive instance parameters with reporting parameters in the past but I do not understand why in some instances it does not work. Even in a generic model adaptive it worked. I learnt it in this video: https://www.youtube.com/watch?v=C98huB1Mmis

[Corsten.Au]

Yeah. That seems fine.. good to know..
Probably that’s true in adaptive points family...
Adaptive point families are most flexible that way..

[ToanDN]

---

@vincent6062 wrote:

Thanks for your response. I usually use a floor to create ramps but I am working on a project where they already have been created using the ramp tool and do not want to redo the whole lot. Plus I use this family to represent the slope of the ramp in plan, 3D and elevation in 3 clicks as I think it is more efficient than creating detail lines in every views etc...

Unless you have a better way of doing it?

---

I don't see any big deal with using floors + ramps versus using generic models + ramps.  If your concern is the lines indicating the ramp then you can simply draw 2 model lines on the floor surface workplane.  They take the same 3 clicks and will show in any views unlike detail lines.  If you want to use an adaptive family to draw the two lines then create a 3 point family and pick the points on the slope surface directly instead of pick them on the plan and use formula to elevate them.  Adaptive family can be placed on any workplane, not just floor plan.

[barthbradley]

@vincent6062: I'm not clear here, but doesn't Revit already have something OOTB that accomplishes the same thing that you're trying to build? The Spot Slope (Annotation Tab) does exactly the same thing; no? 

[vincent6062]

The spot slope tool does not work with the ramp tool.  It works only for the roof and floor tool unfortunately. 

[vincent6062]

The advatage of using a generic model adaptive is that if the ramp slope changes, the generic model adaptive will follow whereas 2 simple model lines will not. 

[ToanDN]

Copy a spot slope from a floor and place it over the ramp and it will show the elevation of the ramp.

[vincent6062]

Yeah! Thank you for the tip 🙂 A little odd that it is not possible to directly place a spot slope on a ramp but this is by far the simplest workaround. Merci beaucoup!

[ToanDN]

If you choose the slope as the workplane when you draw the model lines then they will adapt to the slope changes.

[ToanDN]

And here is a simple 4 point adaptive family placed directly on the slope, no formula needed whatsoever.

[barthbradley]

Exactement, Toan! bon travail!