Join Paul F. Aubin for an in-depth discussion in this video Import tips, part of Revit 2018: Essential Training for Architecture (Imperial).
- [Instructor] I'd like to wrap up our discussion of working with CAD files in Revit with a few tips and maybe a couple dos and don'ts. So, I'm going to start off by reminding you that when you bring in a CAD file, either import or link, you can always select that CAD file and access the information within it. Now remember that the CAD file is organized in layers. So one of the easiest ways to figure out what layer everything is on is to use this Query button right up here on the ribbon. When I click that Query button that will put me in a mode where I'm able to reach in and select individual elements within the CAD file.
And one of the bits of information that I'm probably most interested in is what layer is that item on, in this case A Detail Fine. When I click OK I'm still in the mode and I could select something else and that particular item is on A Detail Bold. Now, in addition to being able to tell me what layer things are on, I've also got some buttons down here where I could manage it further. And one of those buttons is Hide in view. So if I click that, that layer will now be turned off within this view, and of course you can see that that door frame disappears. Now let's do that to another layer that maybe will have a slightly more dramatic effect, let me select one of these leader lines here, that's on a layer called A Anno Note, and if I hide that in view, well then that'll have the effect of hiding all of the leader lines and all of the notes, so a little bit more noticeable of course.
Now, I can get out of the query mode by clicking the Modify tool, and maybe I come to this file later and I'm thinking, well, it doesn't look right, something seems to be missing. If you've previously hidden a layer in the view, how do you get it back again? Well, it turns out you're going to use a standard Revit command called Visibility Graphics. So if I go to the View tab, there's a command right here called Visibility Graphics and the keyboard shortcut for that is v+g. So if you type v+g or click the button that'll take you to this Visibility Graphic override dialog. So this dialog can do a variety of things and we're going to be looking at this again in future videos, but one of the things that we can do here is manage the settings of our imported files.
So if you click over here on the Import Categories tab it will list out each imported CAD file, and then indented beneath that will be all of that CAD file's layers. And then you'll be able to see which layers have previously been turned off right here. If you want to bring those layers back you just simply check the boxes and those layers will be restored. So, that's how you can quickly turn on and off layers. You can either use the Query button to turn them off, or you can use Visibility Graphics to both turn them back on again and actually to turn them off. Now, let me select this once again and click Query and I'm going to select that frame again, and in addition to Hide in view, we also had a Delete button.
Now Delete's a little bit more permanent, so be careful with that. If I click Delete and now I cancel out of the Query button and I go back to Visibility Graphics, go back to imported categories, notice that A Detail Bold is gone, that layer no longer exists. So, there isn't going to be any way to restore it here in Visibility Graphics. So, in general, I think deleting a layer is probably not the right way to go, I'm going to do ctrl z to bring it back and I think turning things on and off is probably suitable in most cases. However, in some cases, if you have a really big CAD file with lots of layers and you know for sure that there's certain layers you don't need deleting those layers can actually help manage file size and performance and so on.
So definitely something to consider. OK, so that's a little bit about managing the visibility and what actually displays on the CAD file and that works equally well for links or inserts. Now, this particular CAD file has been inserted. In general, most CAD or BIM managers would be against using the Import CAD feature. They would always tell you that you should use Link CAD. And of course one of the big advantages of Link CAD is if the original file changes, well, we can just simply refresh the link and capture those changes.
Now you could argue, how often is that going to happen with a standard detail? I mean the whole point of a standard detail is it doesn't change, it's standard, so maybe you don't need Link CAD for that. But just the same I think you might find that many CAD and BIM managers still want you to use Link, even for standard details. But let's say that you did import a CAD file. One of the things you can do with an imported CAD file is one of the reasons why most CAD and BIM managers don't like it. There's this very tempting little button over here called Explode. Now if I click that, that breaks apart the imported CAD file into a bunch of individual lines, pieces of text, and so on.
And at first it might seem very attractive and very tempting, you could say well, that's pretty cool, because now I can select these lines and I can manipulate them and modify them. Now, if you only did that in a small detail like this once or twice, it probably wouldn't be so bad, but exploding a CAD detail actually comes with a decent amount of overhead and it's typically undesirable overhead. For example, if I select this line right here in the exploded detail and I look over here on this Line Style drop down, prior to exploding the detail we had Revit's built in line types, Hidden Lines, Lines, Medium Lines, Thin Lines.
Now we have a bunch of line styles corresponding to the names of the AutoCAD layers. So, chances are those don't match our office standards, and we now have all those extra line styles. But it goes further than that. The same is going to be true with text. So I select a piece of text and it might initially look like the standard text that we use for other purposes within our file, but I look over here at the name and I notice that it's got the word AutoCAD in the name, AutoCAD Detail in particular, and so what I end up with is a whole bunch of text types that correspond to that detail.
So this one little detail brought in five different text types. So you can start to see where the bloat comes in, because it'll bring all these extra styles and types into your file. So let's keep going. If I go to the Manage tab, click Materials, and I scroll down, way down here, under the Rs, you're going to see several materials that have the word Render Material in the name. All of these came from the AutoCAD file that was exploded, so every layer color got turned into a render material, and these numbers just correspond to the RGB values of the colors that were used for those layers.
None of these render materials are particularly useful, and don't really add anything to the project other than bloat. So, that's also stuff that we probably wouldn't want, that we would eventually need to purge out. So, for all those reasons and many more, we tend to want to avoid exploding CAD details. Furthermore, sometimes when you explode them, there isn't a corresponding element type in Revit to match up to what you had in AutoCAD. So for example these lines here used to have arrow heads in AutoCAD, but they've lost that arrow head here in Revit.
So there's a lot of reasons why you might not want to choose the Explode, and in general it's just going to add bloat and file size and potentially corruption to your Revit projects. So, just the same though, let's say that you're convinced that you need to explode a CAD detail, is there ever a time when you should do it? Well, if you're going to do it, there's a right way to do it. And the right way to do it is, instead of bringing it into a live project, like we've done here, go to the File menu, create a brand new empty project, create a Drafting view in that project, import it in there and explode it.
Once you've done that you can begin selecting the elements within the exploded detail, and remapping those to correct settings in Revit. So I could select the lines and put them on a proper Line Style. I could select the text and put them on a proper Text Type and so on. And after I've remapped everything to something correct that matches my office standards, now I can select all of this information, copy it to the Clipboard, switch back over to my project and paste it into the Drafting view and it will leave all that other garbage behind.
So, if you're ever tempted to explode a CAD file, the right way to do it is to explode it in an intermediate file first, clean it up, and then paste it over. And if you do it that way, you'll generally avoid most of the problems that we have with imported files and certainly exploded imported files.
First, get comfortable with the Revit environment, and learn to set up a project and add the grids, levels, and dimensions that will anchor your design. Then author Paul F. Aubin helps you dive into modeling: adding walls, doors, and windows; using joins and constraints; creating and mirroring groups; linking to external assets and DWG files; and modeling floors, roofs, and ceilings.
Paul also shows advanced techniques for modeling stairs and complex walls, adding rooms, and creating schedules. Finally, discover how to annotate your drawings so all the components are clearly understood, and learn how to output sheets to DWF, PDF, or AutoCAD.
- Understanding BIM and the Revit element hierarchy
- Navigating views
- Creating a new project from a template
- Adding walls, doors, and windows
- Adding plumbing fixtures and other components
- Linking AutoCAD DWG files
- Rotating and aligning Revit links
- Working with footprint and extrusion roofs
- Adding openings
- Adding railings and extensions to stairs
- Creating stacked and curtain walls
- Hiding and isolating objects
- Adding rooms
- Creating schedule views and tags
- Adding text and dimensions
- Creating new families
- Using reference planes, parameters, and constraints
- Plotting and creating a PDF