Friday, April 19, 2013

Is it Too Late to Change

Whenever I spend time in the Revit Family Editor I run into past decisions. Sometime they are my own and quite often they belong to somebody else. I've always encouraged people to develop good habits when it comes to using and defining reference planes. I've even been teased about wasting time in a demonstration by naming each reference plane even though doing so wasn't pertinent to the topic. Habits...

I recently encountered a bunch of families that were built by a few people for their project. I was asked to make some changes so a part of the family could be scheduled separately. That meant making use of the concept of making a family "shared". A family that is nested into another is only treated as a symbol when we see it a project. A family that is nested AND Shared is loaded into the project as an actual separate family (appears in the project browser) as well as being visible as part of the host family. This special condition allows for scheduling nested parts as though they are unique parts, apart from the host, as well as permitting us to place them separately. This subject could easily be few separate posts.

While I was digging in I noticed that few if any of the reference planes were named. I also noticed that most of them did not redefine the original reference planes so that they made sense in the context of the family itself. By that I mean that people will use the default Center (Front/Back) or Center (Left/Right) reference planes as a "left" or "right" or "front" or "back" or something...but not rename/redefine them as such. That means that when we examine a family the "center" (the reference plane that Revit thinks is center) of the family is really an edge or side. Autodesk's own content isn't immune to this either.

In this situation I thought like a mechanic, if I've already dropped the transmission I might as well fix some things that I can't get to otherwise, or "while I'm in here"...

Sadly if a project is using this content and people have done things like put hundreds, perhaps thousands, of them in their models, bad things can happen, when they are reloaded. As Mr. Maller says... it can be a "screwtastrophe". Families that have dimensions referencing them in the project will generate the dreaded "dimensions must be deleted" messages as soon as you reload them. Specifically if you change the IsReference status of a reference plane and reload the family Revit can't find the original reference plane anymore. Worse a family might shift its location, particularly if being swapped out for a different version.

I don't think it can be overstated or stressed enough, content needs to be created carefully and good habits need to developed and observed. It may not be too late to make changes but it can be painful.

3 comments:

Anonymous said...

It's too late for change, because Revit never shows any message for better practices when you make a family.
Usually Revit allows to model a building o make a family without any warning, like a CAD drafting software.

Dave said...

Another nice trick is that you can define a Dimension Type that will use a dashed line and add a CL (CenterLine) symbol when it finds a Reference Plane labeled "Center."

We thought it was a great trick, anyway. Until we found a bunch of families that - like you said, Steve - do not use "Center" for the Center.

Aaron Maller said...

It uses the mallerisms or else it gets the Hose. :)

Scott Brown has pointed out to me a few times while digging through my content, that i am guilty of this as well (Not being consistant with whick official references i make the RP's correspond too).

#Failboat. :(