by Tim Alatorre
I started a post a couple weeks ago on tips for creating families in Revit but I didn’t get very far. Our friends over at Inside the Factory are more disciplined bloggers than I and beat me to it. Erik Egbertson put together a great post of Family Editor Tips. He talks about flexing a family, placing Constraints Consistently, not over constraining, avoiding chaining references, shortcuts to duplicating elements, shortcuts to creating dimensions, labeling shortcuts, and a couple other tips.
Initial Setup and Naming of Family Parameters
One thing that Eric didn’t cover in too much depth was naming and grouping of parameters. I also use Eric’s programming syntax method for naming parameters except I usually capitalize the first letter. It doesn’t make much difference really, I just like the look of it in my parameter list. For example, “WindowTrimWidth” instead of “windowTrimWidth”. Although Revit supports parameter names with spaces, I think having your parameters as one “word” makes writing formulas easier.
The first thing I do when setting up a new family is place all of my reference planes, dimensions and parameters. I flex the model with the reference planes and make sure it works. If it does then I’ll start modeling the geometry.
When I first add parameters I don’t write out the whole name for parameters that I know will involve some calculations. Sometimes formulas can become quite complex:
if(and(LoopOne, LoopTwo), DepthDefault, if(or(LoopOne, LoopTwo),DepthDefault- DepthBikeLoop, Diameter))
Make one error in typing this out and you have a hard time debugging it. I start with naming my parameters with shortened names like LO, LT, DD, etc. This makes the structure easier to see.
if(and(LO, LT), DD, if(or(LO, LT), DD – DBL, D))
Once I know everything is working I rename the parameters and they are automatically updated in my formulas.
Grouping of Family Parameters
Currently Revit only allows us to categorize parameters in a set list.
- Analysis Results
- Analytical Model
- Electrical – Lighting
- Electrical – Loads
- Electrical Engineering
- Energy Analysis
- Fire Protection
- Green Building Properties
- Identiy Data
- IFC Parameters
- Materials and Finishes
- Mechanical – Airflow
- Mechanical – Loads
- Model Properties
- Rebar Set
- Slab Shape Edit
- Structural Analysis
- Title Text
I’m glad that Revit doesn’t let us customize this list, it would just complicate things even more. Eric reminds us to “choose a pertinent parameter group for your parameters,” but what does that mean? Really, it depends on your office. I would recommend creating a standard.
I discourage the use of the “Other” category because it ends up being a trash bin holding everything. “Dimensions” is obvious, but I only put parameters in this group that are relevant to the user of the family. I use “Analytical Model” for any behind the scenes calculations or dimensions that the user of the model doesn’t need to bother with; unit conversions, dimension calculations to keep the model from breaking, etc. I have also seen “Model Properties” used for this. If I have toggles for the visibility of different components I put those under “Construction“, if I have a toggle for something that is graphical only, like in an annotation family, I put that under “Graphics“.
Tomorrow we will look at using formulas in families.