Quick export tip & Announcement

First the announcement. I’m sure you know by now that AU registration is open. So if you’re lucky and have the opportunity to go, make sure you sign up for Fuzzy Math Essentials! It’s going to be a great class with an outstanding cast. I’m very sad about not presenting again this year, but I know it’s in very good hands.

Now for the quick tip. I have encountered a couple of cases where someone tries to export a plan view that has electrical outlets to a DWG file and the result has missing outlets. It has happened more than once and when I see that, I always think it’s more than just an isolated problem. It seems that the culprit is usually some filled region in your view, so the workaround is to get rid of the filled region and the fixtures will export just fine. This obviously is not a perfect solution but can get you past the hurdle. You can always combine the hatches from the defective DWG into the one that shows the outlets correctly. Hopefully this will get fixed in an upcoming release.

Quick export tip & Announcement

Clipping of DWG links

I’ve never been a fan of DWGs in Revit projects and my attitude persists. When I started using Revit in 2006, I came across several pitfalls that still lurk with us today in 2010. I think one of them is worth mentioning.

As you might know, when x-ref’ing a dwg into another dwg, you need to decide whether it will act as an Overlay or an Attachment. As a rule of thumb, I always suggest to use the Overlay option. The Attachment option is only to be used when you want that x-ref to come in when the parent dwg is inserted/linked. This is identical behavior to linked Revit projects. Any linked dwgs in Revit will bring in other x-refs if they are Attached and will ignore them if they are Overlays. So far so good.

The one major shortfall is that Revit ignores the clip boundary. It is very common when x-ref’ing a dwg to customize the clipping boundary. You obviously have good reasons to do this, but Revit completely ignores it. For example if I have a dwg file with several clipped x-refs and decide to link it into a Revit project to make it part of the rest of the drawing set, you get undesirable results, and end up with an overlapping nightmare of lines and text. There is really no solution to this issue, unless you are willing to live with some really ugly workarounds, which I’ll refrain from posting!

I wonder how many more years we have to wait to get this functionality? I know I know, just don’t use dwgs. That is usually my answer too!

Clipping of DWG links

2-Mile Limitation (20 mile in Revit 2011)

This is worth echoing and I posted it on the Tips & Tricks AUGI Forum.

Getting around the 2 mile limitation when linking a CAD file (20 mile in Revit 2011)

DISCLAIMER: Be very careful when doing this as you can see severe display issues. Use at your own risk!

In Revit 2010, if you import/link a CAD file with entities that are more than 2 miles apart at the extremes, you will receive a warning and Revit won't let you finish the process. Basically everything in the file needs to fit on a 2 mile diameter "platter". Sometimes you could have a text attribute that is outside this imaginary circle that causes the issue. This tip has two parts to it: how to get around the limitation and how to clean your file so it works without workarounds.
I've been wanting to test out and write about the workaround for a while but I just came across a very well written tutorial so here it is! Thanks go to tonyisenhoff and phyllisr at EUA who shared this detailed tip here.

The second tip explains how to clean your file. Assuming you have a DWG file & Autocad, and you're sure your geometry fits on the proverbial "platter", do the following:

1. With the file open, type the command "select" and at the prompt type "all";
2. Now type "r" to remove objects and window your geometry. By doing this we're creating a selection set of offending objects, which sometimes are invisible. Click/spacebar/enter to exit the command;
3. Now type "erase" and then at the prompt, type "p" (for previous). This selects the selection set completed in 2. Click/spacebar/enter to exit the command;
4. Nothing in your file should be outside of the area you windowed, so save the file and link/import again in Revit. No error or warning should show up.

EDIT: As MrJackson commented, it's much easier and faster to hit CTRL-A to select all, then hold SHIFT while windowing the geometry you wish to keep. Then hit the DELETE key.

Also as of Revit 2011, the limitation has now been raised to a hefty 20 miles. Thanks Factory!

2-Mile Limitation (20 mile in Revit 2011)

DWG visibility in Revit projects

When you link or import a DWG file into your project (with the option "Current view only" unchecked), Revit sees this information as part of the building model and will use standard model visibility rules to display it. If you check the above mentioned option, Revit will see it as view-specific "annotation" and that DWG will be visible only in the view where it was imported/linked.

The use of DWG files in Revit projects varies. The most typical applications are to pull from one firm's detail library and for use as background drawings, such as site surveys, casework backgrounds, etc. I know, not a great use, but when transitioning, you need to somehow eat that elephant in small bites, especially when project size is large and Revit knowledge is not substantial!

When used as backgrounds, DWG visibility could get a bit confusing. For example last week I was helping someone with their project. This user linked a DWG on the first level and another on the second level. Typically, if you open the second floor plan, you would not expect the first floor DWG to show up. The team wanted to quickly bail out and turn it off manually on the second floor plan by unchecking the subcategory visibility in the Imported Categories tab, but that's just bad practice in my opinion. If you go this route, you'll have to manage visibility in every second floor plan view! Not very efficient, isn't it? The key is to understand why it was showing up and prescribe a cure.

We checked the View Range and it was set correctly. We opened the linked file in ADT/ACA and looked at it in side elevation and saw a number of lines going up in the Z direction. Once your View Range can see any geometry in the DWG file, the entire link/import shows up. The DWG link/import doesn't act as a cuttable object; instead, once the View Range overlaps a part of the DWG, it acts as a switch and turns the light on over the entire link.

So next time your "2D" DWG seems to misbehave, just check for those maverick elements that turn it into a 3D object and zero out their Z coordinate values or lower them so your View Range doesn't overlap these elements. You'll be pleased with the results ;)

DWG visibility in Revit projects

A tale of a ghost

So I'm sitting here kicking myself for not thinking of this earlier, but now I'm a better man for it!

Bill comes to me in desperation..."I have an image that is printing in every single section and elevation view, but it doesn't show up in the actual view!". I looked at him in awe....I thought he had a sip too many. "Bill, that can't possibly be true! Don't you know that what's not in your view, cannot print?! That's a Revit basic behavior!". So I reluctantly stroll to his desk and we open up the project file. Sure enough, the darn raster image shows up in the Print Preview. So I start troubleshooting....turning visibility of links, raster images with absolutely no positive results. Then Bill pointed out that if the crop region doesn't include the first level, the image goes away. I immediately start blaming some project corruption on the level and thought that we're going to have to send it to Autodesk Support.

And then it hit me.....I turned off all Imported Catergories (those awful DWG files) and the raster images vanished from the print preview! Hurray! Problem solved. Don't ask me how that raster image got there in elevation in all section/elevation view of all orientations, as the dwg files were used as backgrounds for casework and other things that we didn't do in Revit in plan, but that's what was wreaking havoc. Pretty simple issue to resolve....DON'T USE DWGS!!

Well, use with caution :)

A tale of a ghost