Manufacturer Content - Lighting

I originally wrote the following on the HOK BIM Solutions blog and have since received some additional comments/observations that I would like to add here before re-posting (thanks a lot to Dan Stine!):

1. Revit does not support absolute photometry (i.e. LED IES files). This probably has to do with the format of the IES file where there is a -1 in place of the wattage value for an LED file and Revit is not currently able to handle this, which means you cannot produce renderings for LED Photometry.
2. An IES file describes how light is emitted from a fixture and takes into account all geometry, color, reflectivity and all other characteristics of the fixture. The reflector is only required to be modeled if you’re using a light source to make the fixture look more believable, or through using a self-illuminating material on the lens (the post below will describe all this in detail). These are also invaluable for lighting calculations, not just renderings.
3. Once an IES file is used, the family remembers the information and a link to an external file is not necessary. This is similar to the behavior of MEP families in 2014 which contain embedded lookup tables (note that even though it appears that the Photometric Web File parameter can be connected to a custom text parameter, it does not seem to work. A support request was filed to confirm if this is a bug).
4. Things get more complicated when doing lighting analysis such as with ElumTools, which require lighting content to be created with specific standards:
• Nested light sources must be shared
• Light source ignores all geometry in the host family
• Light from nested families “sees” geometry in host family (e.g. shadows from the arms of a chandelier)
5. Another challenge with rendering in Revit is reflectance. The Daylighting Analysis for Revit uses a formula based on the RGB values of the appearance asset for a given material. ElumTools uses a similar technique (which can be overridden in their Material Mapping dialog) but is based on the RGB value used in the Revit Material Dialog’s Graphics tab.

NOTE: This is a re-post from the HOK BIM Solutions blog

I will reluctantly kick off this post first with a little rant: is it too much to ask from a Lighting Manufacturer, that their BIM content render appropriately? I think not!

I am sure (hopeful, really) that there is good lighting content out there, but I’d like to take you through a specific journey that in my opinion, was unnecessarily painful and is probably quite representative of today’s common reality. So here we go…a user needed to do some “quick” renderings of an interior, utilizing a fixture by Focal Point called “Equation”. Based on the marketing brochure, this is what these should look like:

Here’s the resulting render using the Architectural family downloaded from the manufacturer’s website (for the purpose of this post, I kept the exposure settings constant so you can easily see the relative differences):

It is clear that the family is built incorrectly. The overall geometry might be close enough (it wasn’t to my liking either, so what you’re seeing in this post is a rebuilt version, where I broke it down further so materials could be assigned to different parts of the family, including the internal reflector), but lighting is not emitting through the fixture. Editing the family revealed that the lighting definition was not set to Photometric Web. The MEP version of the family did have the lighting set to an IES definition, but who do we really expect to do an interior rendering? In my opinion, if you have photometric definitions for your fixtures, you should use those definitions exclusively, no exceptions.

After downloading and adding the IES definition to the Architectural family (which was ceiling-hosted…more on that later on), we end up with this:

This is clearly darker than the original version, so the luminance of the original family far exceeded reality. Now, I understand that we’re not designing a lighting strategy/layout based on a rendered image, but we do expect the result to be perceived as close to the built reality as possible. The IES definition gets us closer, however we still need to do something about the fixture itself. The quickest, most efficient technique is to use a self-illuminating material for the lens, which results in a decent render if the fixtures are far from the camera, but would not be suitable for close-ups due to their “flat” appearance. In the example below, the material’s Luminance setting was set to 300:

Self-illuminating materials add to the general brightness of the image beyond what you get out of the IES definition, but there’s really nothing we can do about that, except tweaking the resulting render exposure to get it close to how we perceive the scene should look like.

For a more realistic look, the fixture needs to be built differently. You need to rough-in the internal reflector, place a tubular light source to mimic the lamp as closely as possible, and then nest the family into another one so you can set the additional Photometric Web light source. Since the family I was editing was already hosted, I nested in an empty family into it instead:

The most noticeable and perplexing issue are the inconsistent artifacts around some of the fixtures. I was able to reduce them a bit by shortening the light source, but they would not go away completely (I think this is a bug, but have not yet confirmed…comments welcome!).

The other issue are the harsh shadows, which are a result of the lens material being incorrect (used frosted glass) and can be easily tweaked as we’ll see shortly. With this method you add a significant amount of light to the scene, above and beyond the Photometric Web definition. The image on the left uses the tubular light source only with no Photometric Web. I noticed that I was using the original family’s metallic paint for the reflector and once replaced with a non-metallic white, the scene improved slightly:

Tweaking the lens material was necessary to get this scene closer to the lighting atmosphere resulting from these fixtures, although those pesky artifacts mean that post-processing cleanup is still required to get a presentation-worthy product.

Just in case you’re curious about the lens material, here are the settings I used after some trial and error (click to enlarge).

What an adventure! I really don’t think it should be this painful to make a “quick” rendering using manufacturer-provided content, especially when dealing with lighting. We really need to be able to drop in such families, complete with appropriate material settings, and move on with our design work, rather than requiring a total rebuild, tweaking of their materials and several test renders.

Lighting Content Building Tips for Manufacturers

1. Start with a non-hosted lighting family so you can use the light source that is built-into the family template to emit light from the fixture. This also gives you the flexibility to simply nest into any other hosted family template, rather than rebuilding each one from scratch and making change management difficult for you and your users!
2. By doing #1, the end user can then decide whether using a self-illuminating material for the lens is a better solution and they can simply edit the family to remove the light source (emitting from the fixture) if that is the chosen path;
3. Nesting into a hosted template means you can now also use the Photometric Web definition in addition to the other light source used to make the fixture appear to emit light. If an IES file is available, the fixture should not use anything other than these definitions. Also, make them downloadable together with the families, not separately! It is torture to figure out which IES file belongs to which fixture and which configuration. See #5 to manage these better;
4. Include proper materials!
5. Use Type Catalogs instead of making a plethora of individual families. It is more difficult for you, and for us, to manage them otherwise;
6. Don’t miss building the reflector and the cavity within the fixture where the “emitting” light source will reside. If you only consider the exterior of the fixture, your end users will have to spend a lot of time re-building them in order to produce acceptable renderings. And once they find another manufacturer that does a good job with their content, guess what is bound to happen?

Manufacturer Content - Lighting

Creating Non-Hosted Families from Hosted Versions

I just recently discovered this gem and it seems there are a few people that know about it. Perhaps it was discussed in a forum or some other place, but since I never came across this nice little tip, I thought of sharing it here.

In this post, I talked about a “pseudo face-based family” and this week while I was not even thinking about Revit or anything work-related for that matter, I just had a thought and wondered whether the hosting extrusion could be deleted (I know, my brain is weird sometimes!). So I tested this out and then realized that the resulting family is no “pseudo-anything”, but simply built into a host-less template with the Work Plane-Based option enabled.

So the highly-intuitive process (sarcasm anyone?) of taking a family that is built in a hosted template such as face-based, wall-based, ceiling-based, etc. and produce a non-hosted copy is as follows:

1. Place an instance of the family you want to hack in the drawing area. You can insert multiple ones at the same time;
2. Save the file and close it;
3. Open a new Revit file from no template. This ensures it is completely empty and Revit will thus create this hacked copy when we do step #6;
4. Link the previously saved model into this new file;
5. Go to the Collaborate Tab>Copy/Monitor>Select Link and pick the linked file. Once in C/M mode, click Coordination Settings and make sure that the family types you want to hack are set to “Copy Type”;
6. Click the Copy button and pick the families you want to hack;
7. Finish and exit from this mode when you’re done.

The copied families that Revit created are hacked versions and no longer built inside of hosted templates. Now simply edit the families, delete the extrusions, set them to not be work plane-based and save them…done!

Now I ask, if Revit is able to do all this, why not give us a stupid button instead of this frustratingly long and obtuse workaround?!

Creating Non-Hosted Families from Hosted Versions

Tangential arcs

The question on how to create parametric tangential arcs in families (ex: structural section profiles, extrusion sketches, etc.) seems to come up quite often. And it can be done in Revit: it’s just not as straight-forward.

An AUGI thread resurrected this discussion last month and in my opinion, it was approaching the question from the wrong end. Sure, you can do complicated trigonometric formulas to solve this (I know, I am the Count (Formula) after all!), but it is best to avoid them if at all possible. Intuition says that if you keep things simple and parameterize through simple labels (no calculated parameters), everything should run faster, leaner and more efficient.

So you be the judge. Should you go with this (source: BIM and Beam):

or this?

You be the judge! The key is to use the "Tangent End Arc" type and then constrain along both sides to set where the center of the arc is, (no need to parameterize the arc’s radius). More details can be found in the AUGI post.

EDIT: And even more detail can be found here on Steve’s blog!

Tangential arcs

Fine-tuning of material surface patterns

When materials with surface patterns are used, there is a good chance that you need to tweak its position, and perhaps even rotate it to some degree.

With system and in-place families, this is very easy to achieve, the latter being a little more tricky. So let’s take a wall with a surface pattern for example. You can tab and pick one of the lines and nudge/move/rotate as desired. Even the align tool works like a charm in cases like this. In fact, we use it all the time for tile-work in interior elevations (filled regions are a bad idea for this purpose as you cannot control the fill position/orientation, so painting the wall with a material and fine-tuning the joint locations represented by the surface pattern, is a much better solution). You might be mostly familiar with doing this on ACT ceilings, where you control the position and orientation of the grid by fine-tuning the surface pattern positioning.

When it comes to in-place families, Revit doesn’t allow you to directly control surface pattern positioning. To achieve this, you have to be in in-place edit mode. This is a very subtle, but important fact as you’ll see shortly.

Unfortunately with component families, there seems to be no way to adjust material positioning in the project environment. But recall my point above about the subtle fact…you can adjust the surface pattern in the in-place family editing environment, so why not add some parameters to expose this functionality in the project environment while editing a component family?

As it turns out, you can only adjust the pattern rotation, which is better than nothing. It is really finicky to get it to work and you have to do it a certain way or it won’t work properly. I could not find a way to modify the position of the the fill in the x-y directions, no matter what I tried: ref. planes, ref. lines, constraining to the geometry etc. None seem to work. However rotation works well and I was very surprised to find that even when you change material or the surface pattern (from orthogonal to slanted etc.) in the project environment, the functionality kept working and did not cause the notorious “can’t create type” error.

It is very peculiar to note that you cannot actually flex the rotation parameter in the family editor more than once, or the family will break. Here are the main rules you have to follow:

• The angular parameter has to go from a reference plane to one of the pattern’s lines. I found it easier to use an orthogonal crosshatch while building my test;
• Make sure to set the angle to zero before applying the label to the angular dimension or it’ll somehow try to rotate the pattern (this is definitely a bug) and cause a “constraints not satisfied” error;
• When loading the family into the project environment, the angular parameter has to be zero, otherwise the surface pattern comes in skewed. I noticed that if you load a family with a pattern rotation of say, 10 degrees, the pattern in the project will actually be rotated at twice that amount (20 degrees in this example) and the family doesn’t react when changing the angle between 0 and double the original angle (20 degrees in this example). So make sure the angle is zero when you load it! Just don’t try flexing it in the family editor either or it’ll break.

This technique works for all material application methods on geometry in the family editor:

• Painting a material directly on the geometry face
• Painting a material parameter on the geometry face
• Assigning a material directly to the geometry
• Assigning a material parameter to the geometry

I’m not sure how useful this workaround will be to anyone, but there you have it! Hopefully the Factory will resolve this issue and we’ll be able to fine-tune surface pattern positioning directly like we can on system families.

Fine-tuning of material surface patterns

Face Painting in the Family Editor - FIXED!

Following up on my previous post on the topic, the Factory provided a hotfix for this today. You can read all about it courtesy of Kathryn at Revit Clinic. 13 is such a lucky number, isn’t it?!

To use this functionality, create the parameter first in the Family Types dialog. When you then launch the Paint tool, the parameter will be available as a material in the dialog.

Installation of the hotfix is a snap…just copy and paste the dll.

Face Painting in the Family Editor - FIXED!

Face Painting in the Family Editor

You might recall Steven Campbell’s post Revit Families: To Split or Not to Split… (no, this isn’t his photo. I know, he’s in hibernation at the moment or so it seems). I honestly was unaware of that hidden feature until his article as in the past, I habitually just assigned material parameters directly to solids and never thought of face painting as a parametric option.
Unfortunately in Revit 2012, we lost that ability with the arrival of the new UI that gives us a visual palette of materials when painting surfaces. I really hope we’ll get it back in the upcoming service pack. The functionality is still there as families upgraded to Revit 2012 function properly. However if you “unpaint” the surface, you won’t be apple to re-apply the material parameter. So in the meantime if you need this functionality, start your family in 2011 and upgrade it once you’re done.

EDIT: This has since been fixed through this HotFix. Thanks Factory!

Face Painting in the Family Editor

Type Mark

Model objects in Revit are identified by a unique Type Mark parameter, which Revit makes available only after a family is actually loaded in a project file. As of late, this has become a bit of a stickler.

There are two schools of thought when it comes to templates: the “load it up baby!” group and the “minimalists”. I’m more of the former, but I guess it’s mostly due to some productivity shortcomings in Revit. Now that we actually have a solution in place (Family Browser), I’m officially in the new, middle-of-the-road camp: Load it up, but keep loadable families in your office library only (mostly).

If you load up your template with a ton of families and types, you make it next to impossible (or a big time waster) to use the Insert Component tool coupled with the Type Selector. Unless you have developed a rigid naming system to flock families of a feather to stay together (ex: prefixing with “pfix” for plumbing fixtures, etc.), then there’s a good chance that you have total mayhem in the Type Selector. At which point it makes more sense to simply drag the family type from the Families node of the Project Browser into your canvas. However with Family Browser, you have a more efficient method of loading what you want, when you want it, so that is now my preferred choice.

Unfortunately, on-demand loading presents us with a problem. Until recently, we edited the Type Marks in advance in our template to suit our needs and made sure all details, notes etc. were coordinated with that value. But with on-demand loading, your type mark is populated after loading into a project, resulting in “loss of information/intelligence” as the user has to manually fix type marks in every loaded family. And as Aaron states in his great post about templates, why let your users do something on every project when you can do it once in the template?

This has led us to discontinue the use of Type Marks in our families in favor of our own “Master Type Mark” shared parameter added to each family. I totally understand why Revit adds a Type Mark to a family once loaded into a project, but at the same time there’s no arguing that the current behavior is problematic. Why not let us fill out the Type Mark in advance and just warn us about a conflict once loaded into a project? This would be a much better workflow than forcing us to create redundant shared parameters.

Type Mark

Family Browser

Finally, a Revit add-on truly worth buying! Not only is the price unbeatable, but the improved user experience is something that puts Autodesk to shame (because similar functionality should have been standard in Revit for a loooong time).

I’ve toyed around with the previous version in the past and was on the fence about how it worked, but the new version is ready for prime-time. Their latest patch even includes a screen-capture utility called “Icon Maker” that enables you to customize the thumbnails in case the automatically generated ones are not adequate. Aaron Maller has written an extensive blog post about v2, and just a few days ago, he highlighted some of the new features in version 3.7.

Below are a couple of instructional videos on how to use it and about setting things up.

 

 

These are some of the features I absolutely love about this app:

• Instant Family search with each letter typed in the search box;
• Type Catalog functionality (Create/Edit/Recreate Catalogue);
• Add families by drag & drop from Windows Explorer;
• Add families from within the project environment;
• Create a tab with wall families (more functionality to be added in upcoming releases);

Now, it is highly unlikely for me to not have my own list of wants for a future release, so here they are:

• When adding single families to a palette through drag & drop from Windows Explorer, a link should be established to that family instead of creating a copy of the file. This is a biggie for me and I’m sure it is too for other BIM Managers out there. Linking would open up tremendous possibilities, such as creating custom palettes for each project team or project type and still retain content library centralization;
• When closing the Family Browser and re-opening, it should refresh the list in case something was added/deleted in the referenced family library;
• I’d rather not have to enable borders every time I need to resize the palette (I believe this is an API limitation);
• When using the Locate tools in the BIM Management fly-out, Windows Explorer should open directly to that folder instead of launching a message box. Alternatively, copy the path to the clipboard to make it easy to find said location;

You must be itching to get your hands on it by now, so click here to try it out for free for 7 days and click here for pricing. Your productivity and user experience is about to receive a promotion.

Family Browser

Inside Type Catalogs – Part 2

A common question I get often is how do I declare a certain type of parameter in a type catalog. So I created a cheat sheet of sorts to share.

Discipline = Common

Type of Parameter:	Parameter declaration:
Text	param_name##OTHER##
Integer	param_name##OTHER##
Number	param_name##OTHER##
Length	param_name##LENGTH##FEET
Area	param_name##AREA##SQUARE_FEET
Volume	param_name##VOLUME##CUBIC_FEET
Angle	param_name##ANGLE##DEGREES
Slope	param_name##SLOPE##SLOPE_DEGREES
Currency	param_name##CURRENCY##
URL	param_name##OTHER##
Material	param_name##OTHER##
Yes/No	param_name##OTHER##
<Family Type>	param_name##OTHER##

useful notes:

1. Yes/No values in type catalogs are defined as 1 or 0 with 1 equaling Yes and 0 equaling No.
2. Family Type parameter values are defined as:
   
   1. family name : type name
      
      1. note no “.rfa” in name,
      2. there is a space : space between the family name and type name.
      3. also any inches in the type name require an extra “ mark in the value, so 12” Base is defined as 12”” Base )
   2. family name (only, if family has no type names)

System Parameters:

System Parameter:	Parameter declaration:
Keynote	Keynote##OTHER##
Model	Model##OTHER##
Manufacturer	Manufacturer##OTHER##
Type Comments	Type Comments##OTHER##
URL	URL##OTHER##
Description	Description##OTHER##
Assembly Code	Assembly Code##OTHER##
Cost	Cost##CURRENCY##

useful notes:

1. A known issue with type catalogs and system parameters is that the parameter in the family must be filled out for the type to load the value from the catalog properly.

If this is helpful to you guys, I will expand the list to include other disciplines.

Inside Type Catalogs – Part 2

Inside Type Catalogs

Quick Tip: #1
In Type Catalogs, in order to include inch marks in the type name, you must include a “ mark after the inch symbol.

To display the type name…	In the type catalog, enter…
48” x 60”	48”” x 60””
3’ – 6”	3’ – 6””

Without:

With:

Inside Type Catalogs

Revit Families: To Split or Not to Split…

Materials can be applied many different ways in Revit families, directly to the geometry, by category and even with a parameter but that is not all. One of my favorites is combining multiple tools to create an inlay effect without additional geometry. The key to accomplishing this is using the split face tool along with the paint tool.

In the family editor:

1. First select the Split Face tool and then select the face you want to split.
2. Next Revit will go into sketch mode allowing you to draw whatever shape you want within certain rules, faces may be split either by a single closed loop that is contained within the face or by one or more open loops whose ends lie on the boundary of the face.
3. Finish the sketch.
4. Make sure you have the material created be for moving on to the next step.
5. Select the Paint tool.
6. In the elements drop down select the material you want to apply, then move the cursor over the edge of the face you want to apply the material to making sure just the face you want to be painted is highlighted.
7. Hit “Esc” to end the command.

Additional you can apply a parameter (only in a family) to the face and drive the material by type or instance. To do this, create the parameter first before using the Paint tool. Then the parameter will be listed in the material drop down of the paint tool.

Enjoy…

Steve

Revit Families: To Split or Not to Split…

Copying linework between families

I was trying to copy linework from a Detail Component family to a Profile family and Revit wouldn’t let me, saying that I couldn’t copy between Family and Project. Huh?

Anyway, the workaround is to copy the linework from the Detail Component Family to a view in a Project and then do exactly what Revit says cannot be done…copy the linework back from the Project to the Profile Family. Done, next….

Since this was a short, dry post, I’ll try redeeming myself by urging you to read the latest issue of AUGI|AEC Edge (link in blog sidebar under the AUGI banner) and also to make sure that if you are going to AU, please don’t miss Phil Read’s class on stairs and railings. I mean, if you’re going there just to party, at least you owe it to yourself to go to an insanely great class. Lucky you!

Copying linework between families

Spooky Spiders

I’m a day late to a Halloween-themed post, but that’s ok because what I’m talking about are the four-legged kind. Or three…Or two…

My good Italian friend Diego Minato of RevitLandia together with C.G.C. Tec, an Italian company specializing in glazed aluminum curtain wall systems, have released free Revit families of their products. They can be downloaded from here. You need to register for a free account before doing so.

Then you’ll be asked to fill in your name, last name, email address, re-enter the email address, password, re-enter the password and then scroll all the way down to the bottom to check the typical checkbox to accept the privacy policy. Finally click “Prosegui” (Proceed) to finish up registration. You’ll get an email confirmation with a link to activate your account.

At some point you’ll get to the download screen, where you’ll find a PDF tutorial (one in Italian and one in English), a video that shows how to put a system together (no audio or subtitles; also shows you how to schedule components), and a Revit project file containing all the bits and pieces – curtain walls, glazing, sealants, spider connectors and structural supports.

The system was put together very nicely. You have to model the glazing separate from the structural support system. This was done to circumvent the limitation posed by custom panels, which can only be rectangular. Hopefully you can still understand how to use it even though parameter names are in Italian. Spooky!

Spooky Spiders

Sites worth noting

I’ve been meaning to write about these for a while so here we go:

revitstore

Ian Howard is the main force behind this site. I didn’t know, but Ian used to work for Revit Technologies before Autodesk’s acquisition. This is a great website hosting good quality Family Content from UK Content Autodesk Consultant/Content Developer. It also contains lots of Tips and Tricks that are gradually being added, time permitting.

buildz

Zach Kron from Autodesk has started a great blog. Zach is a wizard with the new curtain panels in the new massing environment (those that Beta tested Revit know this!). I highly recommend subscribing.

As usual, keep an eye on my blog’s sidebar for the latest links to various resources of interest, as I don’t write about every link I add ;)

Sites worth noting

Volume Frenzy

In my last post I made mention to some behavior I ran across when scheduling volumes. The reported figures varied when scheduling Volume or Material: Volume, so I set out to study Revit’s logic. Note that Material: Volume is available in a Material Take-Off schedule, which is the schedule type used for these tests.

To understand the behavior, I ran 3 scenarios by creating a simple family made up of a 1’x1’x10’ solid and then scheduled it. Here are the first set of findings based on the solid’s LOD (Level of Detail):

Next I added a 1’x1’x1’ “control” solid to further understand how these two volume parameters look at solids in families. This control solid was set to Fine only for now (in the same family).

Lastly, I set the control solid to both Coarse and Fine.

As you can see, these values vary depending on the LOD of solids within your families. So you have to be very careful how you build them if you intend to use them for quantity take-offs. I guess you can now understand why I used the word “Frenzy” in the post title ;)

I personally think this logic is a little crazy, but I’ll be eager to read your comments. At least now you have an in-depth study of Revit’s “logic”. Now on to a summary in words:

1. For an object to schedule in a Material Takeoff Schedule, there HAS to be a solid set to Fine detail. A regular schedule doesn’t have this requirement.
2. Material: Volume reads the Total of Fine solids.
3. Volume reads the Total of Fine solids if no Coarse and or/Medium solids exist. Otherwise, it first reports the Total of Coarse solids and if there are none, it reports the Total of Medium solids.
4. There's no clear cut winner of which is the most reliable parameter. My suggestion? If you want to schedule the volume of particular solids, make sure to set their LOD to Fine and then use Material: Volume. Why? Because it has less obtuse rules!

So I ask myself: instead of these “fuzzy” rules, why not have parameters built into each family template which we would use to control what and how volume is scheduled?

PS: Thanks to Daniel for the extensive brainstorming ;)

Volume Frenzy

Scheduling the Unschedulable

The more we venture into BIM (taking real advantage of our Revit models), the more this subject is starting to tick me off. You’ve been warned!

Let’s take a look at what caused this “rant”.

Here you can see the family parameter “Structural Material Type”. I want to use this really bad because I’m doing quantity take-off schedules for all elements, which include structural framing elements residing in a linked file. So I want to create a framing schedule for steel and another for concrete. The reason is that I want to find the total weight of each material in the job and as you know, concrete and steel have different densities.

So to calculate this, one can create a calculated parameter in the schedule and voila. I would prefer to expose the density used in the schedule (so everyone can see it. I don’t like to bury assumed values in formulas if possible). However since the families reside in a linked file, you cannot add this information to your project via a project parameter, so you can only have one formula with a fixed value (one density value). So the only way to do this is to create schedules for framing members with different densities. I know, I can get into the linked file, but that’s beside the point.

Unfortunately, you cannot schedule the above highlighted parameter, which would typically raise the question, then why the %^&**&?!!@? do we have it? How can I filter views/schedules of my insanely intelligent model? I cannot even filter by family name or type either!

This is only one little thing I came across and is very irritating. I found more issues when calculating volumes, but that will be another very lengthy post, so stay tuned.

Scheduling the Unschedulable

Schedule Discrimination

Here’s what I’m trying to do:

1. I have multiple “Parts” built as shared families (Specialty Equipment);
2. Then I’m building multiple Assemblies (also Specialty Equipment) made up of nested families from (1);
3. I want to create a schedule for Assemblies and another for Parts.

There’s no direct way to do this. So I decided to add a Yes/No shared parameter to the Assembly families and filter the schedules for it. You don’t even need to worry about the value and just filter for it’s existence. Now I can easily build the Assembly schedule by filtering for parameter exists.

Notice how every filter option has an opposite (equals, does not equal, etc.), with the exception of parameter exists. Because of that, I cannot really filter for it’s non existence, which is forcing me to care about the value of the parameter instead. I deem that as discrimination!

So the solution is to check the parameter in the Assembly families and filter for equals “Yes” instead. The schedule will then grab all Assembly families. For the Parts schedule, set the filter to does not equal “Yes” (no need to add the parameter to the parts families).

Schedule Discrimination

Paying for Families

As the famous saying goes, "You get what you pay for".

We obviously don't want to pay for families, but one way or another, we're shelling out money to scour the web to find good content or to build our own. Whether you're hiring someone to build families for you or buying them ready-made, it costs time to communicate intent and check the work. Need I say more?

By now you might have heard about Turbosquid for Revit. As the description on the site goes, "Revit Market is designed specifically for Revit users to buy and sell Revit families, scenes, and visualization content." So if you have any families you would like to sell, I encourage you to post them. Or if you're short on time, maybe you'll find what you want at a reasonable cost. You never know, it might even cost you less at the end!

If you read my long posts about BIM content a while back, you know how I feel about the subject. Content is a complex topic, especially when it comes to leveraging BIM throughout the entire life-cycle of a project. I still think that ultimately, the companies that manufacture building products need to provide this content themselves. Only then can the design team trust the accuracy of the data. And would we pay for it? I don't think they'd dare to charge us ;) I believe competition would take care of the situation. The first manufacturer of a particular product that doesn't charge gets specified the most. And the rest will be history.

Oh, one more thing. Until the end of January, you have the chance to win some cash at Turbosquid. So if you have some spare time, now you have an assignment on your to-do list and you might end up a little richer in the process!

Paying for Families

Beams with sloped edges

Steven Debooy, a fellow blog reader, recently asked me if it was possible to add a parameterized void at the end of a beam to cut it at a slope. That question prompted me to write this post about how one can achieve that result.

a) Adding a void to the beam is a possible solution. I posted a family in the Structural AUGI forums in 2007. Feel free to reverse engineer it and find out how it works. My example has 2 voids instead: one handles positive angles and the other handles negative angles. The user inputs an angle in one parameter, and 2 calculated parameters evaluate that input and return the correct result.

b) In the 2009 Revit family of products, one can use the Opening by Face tool to achieve the same result. Using this tool to cut the end of a beam, one will get a warning stating that "Opening partially cuts its host". It's not a serious warning (I guess), but it is meant to inform the user that something could potentially be wrong, as usually an opening is meant to have beam material surrounding the entire sketch perimeter! This is the best option if you want to create custom shaped cuts on the fly.

c) This method makes me mad. Why? Because it's only available in Revit Structure (come on people!). NOTE: As of the Subscription Advantage Pack, this functionality is also available in RAC2010. Thanks Factory!  Aaaanyway, You can sketch a reference plane and then use the Cut Geometry tool to trim the beam against the reference plane (actually you can also trim against a grid). Non-linear cuts are not possible with this technique.

Beams with sloped edges

AU Teaser

I've been trying to wrap up the class material for the upcoming AU and thought about posting a teaser shot ;) I've still got some way to go to finsh the handout and be happy with it, so I'll keep this post short and get back to work. The first class has been at capacity for some time now, but we'll be repeating the class Friday morning at 8:00am (I know, that's a though one! Mathematics first thing in the morning on the last day of AU?!). Hope this spikes your interest. There are plenty more seats available (large capacity).

Here is a link to the session information. The Friday repeat class is not shown in the public view, so make sure to go to your session catalog and look for AB400-1, Fuzzy Math Essentials for Revit Family Builders.

AU Teaser