Parameter per type or per instance ?

[Angayo]

If one opens the Project Parameters window via Manage tab à Settings panel à Project Parameters button and then adds one can sometimes choose between ‘Values are aligned per group type' and 'Values can vary by group instance'.

What should one pick ? The description in the help article ‘Create Project Parameters’ for ‘Values are aligned per group type' appears false. Selecting that causes behaviour described in 'Values can vary by group instance'.

There also may be an earlier option to choose between type and instance. What do these choices do ?

Since the help provides no description of ‘group’, that must be unimportant, right ?

[ToanDN]

The difference between Revit Type and Instance Parameters

Creating Project Parameters (Values are aligned per group type vs Values are aligned per group insta...

I am not sure which document you were looking at but the explanation (in the link above) appears to be correct.

[Angayo]

Thank you for the explanations.

The difference between type and instance used to be clear to me until I started using parameters in Revit.

I have a case where different instances that belong to more than one group have different values.

A possible explanation could be that the meaning of ‘group’ is important and since adding that explanation in the help would be useful, Autodesk decided against it.

I suspect groups aren’t just categories, but elements tied together, the equivalent of blocks in Autocad. In that case I suspect ‘Values are aligned per group type’ means that if I have three pumps in a group, the value of the parameter is the same fort them.

Is that correct ?

[D-Stuart]

Yes to groups in Revit being analogous to blocks in CAD, but no to your assertion that the three pumps within the group will have the same parameter value.

If you have a group with three pumps, and you change the parameter value for one of the three pumps in the group, then any other instance of that group in your project will contain the same parameter value for that one pump. This is assuming you have the "values are aligned per group type" checked. If not, then you will have to edit the pump's parameter value individually for all instances of the group throughout your project.

Hopefully that makes sense, sorry for the word salad.