Question 1: how do you add paramaters to ducts and pipes?
Question 2: Is there a way to add a distance from gridline paramater to duct/pipe centerlines? (in doing so calculate an angle between the duct/pipe and the gridline if it is not parallel to the called out gridline?
Note: Revit basically does this already, if levels were gridlines. It calculates slope, and elevation above a reference level. I want a feature exactly the same except the reference is only vertical (grid) not horizontal (level).
I am just trying to add intrinsic parameters to the ducts to that I dont have to dimension everything on the plans for the field guys to be able to build it. I could just write a special tag. then use the tag all feature. (However we want to get away from plans altogether)
The only contribution I can provide is to mention Spot Coordinate Tags. I know that's not what you're looking for, but I think it may the best Revit can do.
You can add project parameters for ducts and pipes under Manage tab- -Project Parameter, but you can't set Formula for them, and they will not be related to any dimension or parameter, so these parameters will not get the dimension information automatically as you mentioned.
You can try to check in Revit API group to see if this can be done by some programming.