To constrain or not to constrain that is the question

[Tom Weir]

Hi all,
I heard in the past that the model should not be "overconstrained". So I have shied away from locking objects as I create my models. But I am not sure if that is the correct way to go anymore. Maybe things are better now.
How much do people lock objects down? Does it effect performance? Should I just be constraining and locking most items if the blue lock appears? What guidelines are best to follow in this regard?

Thanks and have a great day...

Tom Weir
Los Angeles

[erikbjur]

I lock detail components to the grids and levels. I also lock things together that I needed to line up. If and when the architect changes things. An error message appears when I try to move a wall, which reminds me that I needed this to line up with something else. I can then redesign those elements. I also use locks to keep my foundation lined up with the walls above. I don't know if that helps or not but that's what I do. Its worked fine so far and I haven't seen any performance hit. I model just about everything including the hardware (holdowns, clips, hangers) and then lock them in place if needed. Still no performance hit. Gota love Revit.

[Tom Weir]

So you lock your model objects to an inserted architectural background? I've been wondering whethor that was a sound approach to take.


Tom

[BWG]

Overlocking is still a problem. However, not locking will sacrifice something moving around on you. I have sent things to support and basically told I was over constraining the model. The more modeling you do, the more inherent relationships you create. Just the nature of the beast I guess until we can give the factory a better idea of exactly how we want this locking/relationship issue to be dealt with.

[erikbjur]

So you lock your model objects to an inserted architectural background? I've been wondering whethor that was a sound approach to take.


Tom

Not many architects we use, use Revit. Pretty stupid if you ask me, but that's another rant for another day. I usualy build the structural model from scratch, so there is no architectual model to lock to. In the case where an architectual model is available, I copy the levels and grids with the copy monitor tool. It seams to work great so far. The drawings have to be coordinated anyway, so either way you will be moving detail components around. What has your experience been?

[Tom Weir]

Hi,
I also have used the copy/monitor feature (only once though), and that is great for models. But what about locking to a 2d autocad inserted arch. background? As BWG is saying there is a problem with overconstraining. But how do you measure when you are reaching that point in your model development?

Tom

[erikbjur]

I assume there are mistakes in the Autocad drawings. So I don't lock to it. I model my building off of the Autocad base and then bring the mistakes up the the Architect. In response to your question, I think you only find out you were overconstraining when that dang error box comes up.

[BWG]

I sent a model to support and they found 36 locks on one item, but I only pushed the lock button twice. So, additional relationships were created and who knows when that is happening and why! So to know when how many is too much, that is impossible to answer. The more complex the model, the more constraints that will be formed whether you lock it or revit does it. I try not to lock anything, but that means checking over the drawing a lot to make sure things have moved. If I do lock something, I try and remember to unlock it when I think I am done. The exception being the model lines we tie down for use in elevations views which we lock, but it creates a lot of constraints beyond just the ones you choose.