Demons In Your Data?

The more you work with Revit the more likely you are to run into demons in the data. What do I mean by demons? Demons are unexplained behaviors. I'm not talking about software bugs that won't go away until you've installed a software update. I'm talking about errors in the data of the project file itself. Errors that can be repaired by replacing the corrupt data with an arbitrary value and then changing it back again.

Somehow, the process of changing the offending data to something arbitrary, then changing it back to the way it should be can remedy unexplained behaviors. I'm not talking about changing a value and then hitting the undo command. I'm talking about using Revit's tools to change the data to something arbitrary then changing it back... like the change is some new data for the model. It's just a matter of isolating the parameter values that are causing the unexplained behaviors... then finding the right combination of commands that will reset or refresh the offending data. These commands might include flexing parameters, cut & paste in same place, nudging, or possibly other commands. Let me give you some examples...

I upgraded a model once, from Revit 2009 to Revit 2011, and an odd thing happened. In hidden line mode, half the doors and windows had shaded glass (by design) while the other half had no shading. And it wasn't like there was any consistency... the shading was gone from random doors and windows. I realized at that point that I had a demon in my data, so I went into the offending material (glass) and set the surface pattern of the glass material to none (it was the surface pattern that was not cooperating), then changed the surface pattern back to solid fill to get this glass material to show properly everywhere.

Another thing that happens a lot... I like to nest families into a host family and link the parameters of the nested family and its host family, but once in a while after making a change to a nested family and loading it back into the host family, solids disappear or just don't flex when the family is loaded into a project. I have to flex some of the linked parameters, while still in the family editor, to reset or refresh the offending data.

Wall cleanups at intersections (not to beat a dead horse) can also cause demons. Sometimes nudging one of the walls can cleanup your intersection. Sometimes you have to cut a wall to your clipboard and paste it back into the same place to get intersections to heal properly. In fact, when any family (that was working fine before) isn't cooperating try a cut and paste in same place. This can reset data in the model.

If any of my readers are familiar with a particular demon please feel free to leave a comment describing the demon and how you "exorcised" it.

Remodels in Revit... the untold story

To my surprise, there's not a whole lot of discussion on this very important topic. Anyone who has developed large remodel projects in Revit can tell you, it's not as clean and easy as starting with an empty model. There are rules we have to follow if we want to develop a remodel project in Revit.

The first step is pretty staight forward... build your as-built model in the existing phase. Once an as-built model is done I like to archive a copy of the model just incase the design scope changes and we have to start all over again with a clean as-built. Now I'm sure you are all aware that as the design develops the project architect and the client are both going to want to explore varying design iterations. The model builder is going to have to do partial demolition of walls, floors, roofs, ceilings, etc. The way most Revit Beginners go about doing this is to split the wall, floor, roof, etc into two parts and demo the half they want to remove (just like you would on a construction site). The problem with this method starts to reveal itself after 2-3 design iterations when the as-built model has so many pieces split apart that mending them back together is too challenging and time consuming. You could split and mend, split and mend, split and mend each design iteration, but we prefer not to do that because it's still time consuming.

So what do you do with partial demos? We create a new phase between Existing and New Construction called "Existing To Remain." We then copy the element to be demo'd to the clipboard... then demo the whole element in the "Existing to Remain" phase... paste the element (into the same place) back into the "Existing to Remain" phase and then reshape the new version of our element. Now anytime the design goes through iterations all you have to do is reshape the new element while leaving the as-built model preserved and intact. Call it a workaround if you like but that's how we preserve an as-built model throughout the life of an ever-changing project.

Other notes on remodels:

• Replacing windows and doors can be done by placing an existing opening family in your wall... loading in an existing wall hosted door/window (one without an opening) and demolishing the family while leaving the opening family intact... Then load a similar new door/window into the model to replace the existing element.
• Wall cleanups can also be challenging for remodels. You'll likely have to use a combination of edit wall joins and miter or disallow join and join geometry to resolve these connections so your plans and elevations are clean no matter which phase is shown.
• When you reshape a roof it's very likely that at the same time you'll be reshaping an exterior wall that is "attached" to the roof... so you'll have to do partial demos of both the roof and the wall.

This all came up because I was in a meeting yesterday with a project architect. He informed me that one of our projects was going to be redesigned and that he wanted us to reinstate the as-built model and start from scratch, but when he went into the model to try to work with the as-built it was "a mess" because the as-built model was grouped and pinned (and he didn't know how to work with a model that was setup like that). All I could think to myself was "YES! I grouped and pinned the as-built model because I didn't want anyone screwing with it."

It took me 30 minutes to remove the previous new construction work, isolate the as-built model, link it into a new blank project template and bind the as-built model so we could develop this new design with our latest project template (this was an older project that was coming back to life).

The as-built model is sacred ground. Once it's built you have to work to preserve it.

When is a Family Parametric?

Question: When should I build a family that flexes?

Answer: Anyone who knows the family editor can tell you, it takes time to build complex families with parameter driven flexing geometry. They can also tell you that some families flex... and some don't.

Question: Why would you want a family that doesn't flex?

Answer: The more complex your geometery, the more difficult and time consuming a fully parametric family is going to be and we all have deadlines. On top of which, your client might change the design of the component dozens of times. Do you think your going to have time to remake a complex and fully parametric family dozens of times? Probably not.

Question: So what do I do with highly complex and custom families that will likely change from week to week?

Answer: Build a placeholder family. A placeholder is a family that has just enough geometry to illustrate the component in your plans, elevations, and sections. It doesn't have to flex, it just has to illustrate your design intent.

Question: So, now that the design of my component is finalized, now I can make it fully parametric right?

Answer: The only families that are worth the time it takes to make fully parametric are families that are going to be used over and over and over again in most of your projects. For instance we have typical doors, windows, fireboxes, raftertails, roof tiles, etc. that we use all the time. These families are worth spending the time to make fully parametric. But, we also have custom doors, windows, etc. that are custom made to fit a given project, and no other. These families are often not typical in shape so we don't take the time to make their geometry flexing just for the sake of the one project... We do however make sure that their parameters schedule correctly in the final documents (whether the family flexes or not).

Families that are fully parametric can also be difficult for users to "reshape" after the fact without running into countless warnings.

Should I enable Hardware Acceleration?

Hardware Acceleration (in options) controls the performance of several features in Revit 2011 including:

• realistic materials in realistic view
• ambient occlusion
• performance of mechanical views
• performance of underlay views
• performance of overall project

To find out if your graphics card supports hardware acceleration, Autodesk has now published a Supported Graphics Hardware List for Revit 2011.

Often Overlooked By Beginners (Part 2)

One of my earliest posts focused on little tools that are often overlooked by beginners. I thought I'd revisit this topic now that I've had more experience working with Revit Beginners. Here are a few more tips that beginners are often not aware of:

1. Wall Location Lines. The location line is kind of an anchor point for a wall. When you flip a wall (ie. change its orientation) the wall will flip about its location line. So if you wanted to flip a wall without affecting its position you could make the wall's centerline its location line as well. Location line is controled in a wall's Instance Properties. Some of your choice settings for the location of the location line include face of core, face of finish, wall centerline, etc. When a wall is selected you might notice two blue dots at either end of the wall. Grab this blue dot and stretch the wall to any length you want. You might also notice that when you change the location line of a wall this blue dot will relocate, reflecting your newly chosen location line.

2. How do I fillet two walls (or lines). A common thing for beginners, is to go right to the trim tool in search of a fillet option (because they are likely more familiar with AutoCAD). Well in Revit the fillet tool is located elsewhere. If you are drawing a wall or a line there is a pallet of line shapes that you can draw (square, polygon, circle, arc, etc.) Well fillet is one of those options circled below.

3. Stretching a gridline in the current view only. When working with gridlines for the first time a beginner will often take notice that stretching the end bubble of a gridline stretches the grid in all views globally. The next question they ask is, "How can I stretch it for this view only?" Well there is a little icon next to a grid bubble that reads "3D." Click on the icon and you'll notice that it now reads "2D." You are now free to strech the gridline for the current view only. The location of the original 3D grid bubble is at the hollow circle you see below.

4. How do I host my railing on a ramp or stair?: Ok, so you've sketch a new ramp or stair and you want to add a railing to it, but the railing is resting on the first floor and doesn't slope with your ramp or stair. Well, when you're in sketch mode shaping your new railing path, there is a tool called "Set Railing Host." Select this tool and then select your host (stair or ramp). Your railing will now slope with the host as was your original intention. Remember, the railing tool is located on the Home tab and is its own sketch. Do not try editing the sketch of your stair or ramp to add new railings. I've seen beginners try this alot.

More beginner tips to come...

Editable Worksets and Workset Ownership

Here is a tip for beginners working with Worksets for the first time.

Let's say you have a project with worksets enabled and the whole model is on Workset 1 by default. If you right click on an element that is on Workset 1 and select the option that reads "Make Worksets Editable" you are making yourself the Owner of Workset 1. No one else is going to be able to edit ANY modeled elements that are on that workset. They can add elements to Workset 1 but they can't edit elements already placed.

If you go to Collaboration... Worksets... and you see yourself as the Owner of any workset you're probably locking everyone else out of that workset so make sure you click on the "Non Editable" button to relenquish the user-created Workset... or do a save to central and relenquish user-created worksets so other users can work on the model too.

What you more likely want to do is borrow... or select the "Make Elements Editable" option instead so you are only borrowing a small part of the worksets rather than Owning the whole workset.

Just a heads up for you beginners out there.

In-place Cavity Walls

If your cavity is a constant width along the length of the wall (like the angled exterior wall shown on the right) you can just add the necessary layers to a basic wall family, but if you have undulating cavity walls, like we often do, you might want to consider an in-place wall family like the one illustrated below in blue.

This wall is the sum of two 9' tall extruded shapes in plan view... one for the overall mass of the wall (thicker line) and one for the stud layer (blue). The challenge with this approach is in getting the wall to show properly in coarse AND medium detail modes.

The way we achieve this is first to set the visibility settings of the stud layer element to hidden in coarse mode (select the stud layer element while in the family editor mode and set the element's visibility settings). The other setting your going to want to set is to assign the stud layer element to the Common Edges subcategory (within the instance properties of the stud layer element). This will thin the lines to match the stud layer of all the surrounding wall families. Use join geometry to get the surrounding walls to cleanup when they meet your in-place cavity wall. If anyone has anything to add to this issue please feel free to comment.

Some New Bloggers on the Block

Steve Swensen is REVIT GUY
Oliver is the author of Revit In Motion
and you can find more interesting reading at revitflow

I look forward to reading your posts guys.

More Decorative Line Drawings in Revit

The question of whether to use AutoCAD or Revit took an interesting turn within our office some time ago. In the beginning we were pushing to use Revit for everything just to see what it was capable of and we found that AutoCAD still had a place in our office.

There were a couple of factors that determined our methodology:

1. Most new hires know AutoCAD and not Revit and can work fairly quickly in AutoCAD.

2. When it comes to 2D detail like decorative tilework on a wall or other highly decorative components (that would take too long to model in Revit) these elements can be drafted in AutoCAD fairly quickly and then imported for placing on a surface. It's very important to know a quick method like this for generating detailed line drawings that might change frequently in the schematic design phase as they often do on our projects. In addition, if these AutoCAD files are LINKED in they can be updated frequently by a draftsperson and then reloaded into the Revit model without having to reposition them. AutoCAD files can be placed in the "current view only" or can be placed 3 dimensionally in all views, but it takes a little longer to orient a linked dwg in 3 dimensional space onto the surface you want. We only do this when we want to see low relief detail in a camera view.

3. Revit is very useful for solving 3D problems, like determining valleys and ridges of awkwardly intersecting roofs for generating roof plans or elevations and for seeing into the structure to resolve other possible clashes.

4. In addition to linking dwgs into a project you can also import them into families. We do this a lot for our flush doors when we want to add a lot of custom detail to a flush wood door. Rather than model all that detail, just paste the dwg onto the surface of the flush door.

5. AutoCAD files are a good place holder until such time that the design changes settle down and you can find time to model low relief elements.

In conclusion, if you do have a practice that designs a lot of decorative detail into your custom architecture, consider using AutoCAD to draft your detail and then nest the dwgs into your projects and families. While this method may not be practical for offices that are interested in the rendering features of Revit, they are very practical tips for quickly generating line drawings for schematic design and construction documents using both Revit and AutoCAD.

Additive Views vs. Subtractive Views

Common Problem: When I place an electrical fixture or other family category it pops up automatically in other views I would rather not see it in.

Reason: In the default Revit tempate almost every category is unnecessarily turned on in all views so the same family shows up everywhere.

Solution: Create Additive Views instead of Subtractive Views for family categories that are only used in one or two views. By that I mean, start with most family categories turned off in your new view's visibility/graphics and gradually add the categories that you want to see.

Extra Tip: If you want future new views to be additive by default, create a view template. Then, when you apply the template to a view, check the option that reads "Apply automatically to new views of the same type."