Getting Started with Customizing Dynamo for the Non-Programmers Using C#

MARCELLO SGAMBELLURI: Hello everyone. Welcome. How is everyone doing?

AUDIENCE: Excellent!

AUDIENCE: All right.

MARCELLO SGAMBELLURI: Is everyone excited about the class?

ALL: Yeah.

MARCELLO SGAMBELLURI: Yeah, all right! Woo! Good AU?

ALL: Yes.

MARCELLO SGAMBELLURI: Awesome, awesome. Thanks for joining us. I know yesterday we had a good time, so I appreciate you coming to our morning session.

I am Marcello Sgambelluri. I'll be your presenter for today's lab on getting started with customizing Dynamo for the non-programmers using C#. Boy, that's quite a mouthful, isn't it? But I tried to make the title as descriptive as possible. I am going to be joined by my very helpful and very skilled lab assistants, Carl in the back, as well as John, as well as Sebastian. And Patrick, you can lend a hand as well if you like.

So this way it's going to work. As we're rolling along, if you have a question for me, you can ask me any question you want. You raise your hand and look towards me. If you have a technical issue, something's not working, you turn back, raise your hand and look at them. Got it? Yeah? OK, awesome, awesome.

Oh my gosh, I'm so excited. This is the first time I've ever taught a text coding class. Woo! We're going to see how it goes.

So, how many people here are Dynamo users? Oh, wow, awesome. And how many people here are C# coders?

[AUDIENCE LAUGHS]

That's OK. Do you see this description-- whoops! You see that? That says for non-programmers. So I will not assume you are C# coders. I won't even assume you're a Dynamo user. You just have to be a Revit user. Anyone here a Revit user? Yeah!

So what we're going to do, we're going to have an awesome time today. I'm going to introduce you to something called "zero touch." Zero touch is a way to use C# to create Dynamo custom nodes. How does that sound?

So we're going to be making Dynamo custom nodes today. Forget about the "out of the box" stuff. Forget about all those packages out there. We're making our own stuff today.

So we are going to start with the fundamentals, but we'll slowly take off. In front of you-- may I borrow this-- in front of you, you have a cheat sheet with eight examples. We are going to try to get through all eight of these today. And if you have any questions-- like I said, if you have any question, shout them out. Has anyone seen me speak before?

AUDIENCE: Woo!

MARCELLO SGAMBELLURI: OK. So I get really excited and lively up here, so I'm going to run around. So just bear with me. So a little bit about me really quick, I'm Marcello. I've been teaching since 2012. I'm a licensed civil and structural engineer. I've been using Dynamo since 2014.

And I also run a blog site called Simply Complex. Check it out. That's kind of what I do. I try to break things down that are complex into simple things.

YouTube channel, got a podcast, check it out. I started recently at Comic Strip, so check it out. So we're going to get going.

So this is how it works. Ready? So these are what I call my Dynamo cheat sheets. I'm actually going to be publishing a book hopefully next year. And this is just really basically the way it works.

We got a section up here that says this is a title zone. It's what we're going to be doing. This is the code zone. This is the code you type in.

And then basically this is the geometry node. This is basically what nodes pop out of that, and just what happened, and pretty obvious stuff. But I'll coach you through it so you won't have to really be looking at that handout.

If you'd like to take this home today, feel free. Please leave it, if you don't want to because I don't want to see it in the garbage outside. Everyone ready to go?

AUDIENCE: Yeah.

MARCELLO SGAMBELLURI: Yeah, OK? So I am going to tell you one more thing about myself. Tomorrow-- no, excuse me, in one week, I will be celebrating my 20th anniversary at my company. I've been there 20 years. Thank you, thank you, thank you.

[APPLAUSE]

So the first thing-- when I tell that someone, the first thing they ask me is how old are you? So I was like, you know what, why don't we make a Dynamo node that calculates Marcellos' age? That way we get it out there. Is that a good way to start?

We'll do that, and then we'll hit that Revit API. Sounds good? All right, let's do it. You got all that.

There's just a few things I need to explain because we can't really have time to go into it. We're going to be using Visual Studio today to get into the code. There's a lot of presets that you have to do. You can Google it. It's also in the handout in description.

But basically, you just create a project, you create a DLL that you're going to be saving to, a DLL that you're going to be saving to. You're going to name it, and then you add references, and you add using statements. That's all spelled out.

We're not going to go over that because I want to hit the code-- I want to get into the meat of the code. So if you have any questions about that later, ask me later. It's all spelled out there.

Our pre-examples in the handouts-- so the way it works is like this. So basically, the handout has these eight that I talked about. It has additional ones, eight more. And these are just basically how to step into it and get started.

So everyone cool with that? You can read that. Let's do that code.

C#-- oh, and by the way, I always traditionally bind my handouts and get to pass them around. So these covers are-- there's different covers on these. There's about 150 pages of the draft of the book I'm going to be making.

So go ahead and pass it around, check it out. Have fun with it. Here you go. In my last class, those were stolen. So if I don't get them back-- if I don't get them back, then that means I've made something worth stealing.

[AUDIENCE LAUGHS]

So let's do it. Let's do it. John, how did we do on the intro? How many minutes?

JOHN: Eight minutes.

MARCELLO SGAMBELLURI: Oh, eight minutes! I tried to save it under seven. Here we go. So I'm using my computer, so the data sets are in a slightly different place. But these awesome lab assistants will help you.

So if you look at the data set, you have to navigate to the desktop and then to today's class, which is called "Getting Started." Can you get there? And then under there, you're going to see a series of these folders.

So 00, 01, 02, 03, 04, are all ones that get you-- get all the whole thing setup. So we won't go through that. We're going to jump right into number five called "Get Age."

You're going to get the hang of this. C# needs to compile. You need to close it, you need to open Revit, you need to open Dynamo. You need to load the DLL, and you need to run it.

So there's five steps we have to do through each exercise. So you'll get used to it. So they're all kind of-- they're all-- it's all going to be systematic.

So you go into number five, Get Age, and there's a final, and there's a start. We're going to start with the start. And that'll be the 0-- that'll be the Visual Studio script that we're going to be creating. At any time if you get lost, or you want to, you can always open up the final and use that because it's a completed one.

So go ahead and click on Start. Now, you've got to double check the folder you're in because you can mess yourself up pretty bad, so Get Age and then Start. Now, you're going to see this folder-- this file here called .sln. That's a Visual Studio solution file. Go ahead and double-click on it, and it should ask you what do you want to open it with. Open it with Visual Studio.

Visual Studio Community is free if you'd like to get it. It's completely free. If you want to know more about Visual Studio, Google it.

[CROWD CHUCKLES]

So here's the environment that we're going to code in. Just basically look on the far right. There is a file called a .cs. This is going to be our-- it's basically a class file. I'll explain what that means.

So just real quick with the architecture, these are using statements. These just basically help the programmer so you don't have to type everything out. Like RivetService.transaction dot dah dah dah, it's like short script. That's all that is. You don't need to care or know about that.

One other thing is up here, there's references which I already preloaded. In here, we have some very important ones, Dynamo. The handout tells you exactly where to get these.

And you have the data set, and they're already in there. So if you want to start doing this, you can just copy this over and grab the references. So you don't have to necessarily know where all these come from. i get that common question.

And then also in here is the Revit API, which is awesome. And then one other here called friends example. I created a database of all my friends. And they know all my ages-- my age. So we're going to tap that reference. You got it?

That is where the file is to figure out where my age is. You understand I get that question, too. Like where did you-- I just load it in a reference. I made it, and loaded it.

How to make references is way beyond this class. This is an intro class. Clear with that? Awesome.

First thing is in C#, you have to have a namespace. A namespace is like a book. Where did my book go? Somebody already steal it?

So a namespace is like the name of your book. Getting Started, that's the namespace. Basically the way it works.

Then under there, you have a class. A class is basically the name of the chapter. And then under that you have a method. And the methods are like the sentences that do things.

So I already created a namespace for you and add a class name. We're not going to be doing that. We're going to start with creating methods, the actual meat of what happens. I didn't want to foul anyone up with having to type all this stuff out.

Cool with that? That means we can just hit the ground running. We're going to create methods. Methods are also called subroutines. Those are the sentences in the book, and that's what the meaning is.

So let's get going. Lab assistants, do you see this on everyone's screen? Do I get a yes?

So I made this really easy. I just put code here. If you put two forward slashes in C#, it becomes a comment.

So we're just-- whenever you see place code here, that's where we're going to be typing our code. And if you need help, it's always down here. It zeroed out-- I mean, commented out. So we're going to start typing here. Everyone with me?

Now, this is the way it works. Let me back up and show you something here. So on our first example-- so I'm getting-- I'm getting really excited about this, holy smokes! I don't move too fast.

So this is going to be the end product. This is my-- did it show my age? Oh no, good.

So this is the code we're going to write, pretty simple. And then this is what pops out, a Dynamo node that's going to calculate my age. We were going to do-- we were going to do this one where we have an input port. This is one we're going to do.

So this is the end game. You always want to know what you want to do in the end. We want to make a node that calculates-- shows Marcello's age and maybe has a fudge factor on it depending on who I'm talking to.

Does that sound like an appropriate input port for an age node, maybe? It defaults at zero. Come on, give me a break.

So, let's do it. Woo! This is Visual Studio. So this is the only time we're going to actually type out the class in the-- I mean, the method in its entirety.

The way it works is, remember, we got the book name of our book, we got the name of our chapter. Now for zero touch, you have to actually add this private. It just hides part of the node. You don't really need to know-- necessarily know that.

Let's create a method. So what you've got to do is you've got to make it public. What public does-- go ahead and start typing with me. What public does is it says that it needs to be accessed by basically Dynamo. It's got to be static so that-- it has to do with the instance of it.

You don't need to know that too much. Just say public static, and go with it. But every method you're going to write, woo, 99% of every method you're going to write's going to say public static. And this is an intro.

Next, you have to ask what is coming out of the output port?

AUDIENCE: Age.

MARCELLO SGAMBELLURI: An age, an age, my age. So, C# is very type-based. It is a stickler for type.

By the way, if you're not a Dynamo user-- I did see some hands that didn't go up-- the power of Dynamo is it always sends information out. There is always an output port on the right side of that node-- anyone can challenge about that, I said always-- because that's a point.

So we send something out. What are we sending out? We're sending on an age.

Now what's the type-- what's the type of that? Is it going to be a-- what we call a doub-- oh, who said integer? Very good.

Yeah when he says, hey, what's your age? You say, I'm 24.785 years old. I don't do that.

I mean, maybe they do that with the toddlers. Oh, they're 12 months old. They're 24-- 30-- where does it start, 48 months old. I don't know. But anyway, you get the idea. So you think, what am I going to send out? And int makes more sense.

So you have to start-- when you start a method, a method, you have to say public static, and the first thing you do is declare its type, which is going to be the output port. So that would be an "int" or an integer, which has no decimal places. So go ahead and type I-N-T, I-N-T.

Now space, the next thing you do is you have to actually name the method. The name of the method is also the name of the node. [GASP] How cool is that? You get to name your own node. Cool? You like it?

So I called this Marcello Age Node. So, I mean, you can go ahead and do that. Methods typically start with a capital. And if you have more than on word, go ahead and make it uppercase because that's called camel script.

It just helps you find the-- don't put spaces in coding. You're going to get yourself in a world of hurt. So do that. So that's basically it.

Now, a method, when you see these two parentheses-- has anyone ever seen those before, like at the end of something? You're like, what does that mean? That just means a method is running a program. A function is running.

If there's nothing in it, that means it requires no input. So if we ran this thing, and we left that blank, can anyone tell me what you think would happen with the Dynamo node?

AUDIENCE: There's no inputs.

MARCELLO SGAMBELLURI: It would have no input port. But I want to put a fudge factor on my age, so I want an input port. So that-- what goes in there is input for my method, which is also in zero touch, and in Dynamo, and input port. Yeah! So we get to name the input port.

So you have to, again, declare a type. What do we want to have in? Our fudge factor should also be what? What do you think?

AUDIENCE: Integer.

MARCELLO SGAMBELLURI: Yeah, an integer. So go ahead and type "int," and then say-- I like the word fudge factor, I don't why. But, I mean, you can name it anything you want. Now one more thing, do you ever see how these things laying out? Super awesome. I love this parallel.

One more thing, if you didn't do anything else, that input port says I don't know what I'm equal to initially, so I'm going to be blank. But if you put an equals to and a certain value, can anyone guess what that would do with the input port in Dynamo?

AUDIENCE: Default.

MARCELLO SGAMBELLURI: It would be the default value, yes. So I probably don't want to default at minus 10, like I'm a nice guy. I want to default at zero. So you put equals 0.

So any time you look at a node in Dynamo, that's what is happening. It actually has a default value. So like create a point at 0 comma 0 comma 0, and you putt it down, and it has node at 0,0,0, that means the defaults are at 0,0,0.

So someone went in there and put equal 0. You understand, so do 0, equals 0. Believe it or not, we are almost done, almost done.

Now, any method needs to be-- so this is basically the name of the method. But you need to tell it to do something. Everyone with me? In order to do that, you have to enclose in it curly brackets. So put your curly brackets, or braces-- I don't know, whatever you want to call it. OK? Yeah?

Believe it or not, we are learning the fundamentals for everything we're going to do today in this example. We are only going to be regurgitating this, but with the Revit API. That's why I decided to use something a bit more simpler.

Now, just like the Revit API, just like a building, you want to know something about it. So you see me, and you're like, I wonder how old that guy is, but I can't just go ask him. Hey, how old are you?

Let me ask my friend. Hey, do you know that person over there? You're his friend, right? Do you know his age?

Or no, better yet, introduce me to him. Hey, can you become my friend? Now once you're my friend, and I get to know you a little bit, you start to release more information to me.

So that's what you've got to do with the Revit API. You see a building, and you see a wall, and you want to know its length, you're like, hey building, I want to get to know you. Hey, can you show me your wall? Oh wall, can you show me your length? Oh, the length.

So that's the way it is. So you've got to ease your way into it. Hey Jen, you can't just go, bang, Marcello age. You can't do that. So first, talk to my friends.

So, let's go ahead and type "friends." And if you type friends, then it accesses that reference. That's basically like calling up a building element or a building object.

Now, there's something we're going to do to expose something under that. The most powerful thing in C# coding, it's called a period. It's a beautiful thing. You type that period, and it's going to show you some goodness. So go ahead and type a period and see what you get.

So, you go like this-- [GASP] oh my gosh, we got Marcello in here, we got a few others. You know what, I'm going to pick Marcello, Enter. This is how you do it when you find the length of a wall, you grab the building, and you're like, period [GASP] look at all this good stuff! I found a wall! [GASP] I found its length! Got it? See what I'm saying?

So push a period again. What did you find? [GASP] More stuff about Marcello. I found his age, his height, if he knows Dynamo, yes or no, his location.

So we want to do age. That's it. That now establishes-- that's actually pulling that data from that database. If you do that, you have to actually end it with a semicolon.

Next is-- next is something more important. So you created your method, you have your node, it knows what it's named. You found Marcello's friends, you found Marcello, you found his age.

Well, C# says, that's awesome. That's perfect. I'm going to keep this to myself. I'm not going to let anyone know about this. You're like, like the hell you aren't.

So there's something you got do. You've got to get it out. You've got to get it out of that method. You've got to send it out. You've got to return it. That's right.

So you can type-- you can basically-- for the sacred-- for the sake of time, we could make this another object and be like, Marcello's Age Object, and we can return that object. But just for simplicity, we're just going to go ahead and return that whole thing. So if you just type "return" in front of it, it'll actually-- so go ahead and find return, return, right there. And it returns that portion. You see what I'm getting at?

That knows to send it out to that output port. Does that seem difficult to you? Does that seem difficult to anybody? No, but you're like, yeah, let's see it in action.

So you're almost there. We need to compile this created DLL, load that into Dynamo. You ready? Yes? Now, let's do that, and then I'll explain other ways you can do it.

So you just come to the top here, and there's a lot of ways people do this. You can compile this and step through the code. I'll let you Google Visual Studio on how to do all that. But this is an intro course, so I'm going to show you just one way to do it.

You come over here, and you say "build" and you say "build solution." Keep an eye on the bottom left. It should say "build started," and then it should say "build succeeded." If you see build succeeded, you'd be like, yes! And you're ready to go.

A DLL has been written to a default location. It's weird. You can change the location if you want. But for me, I left it default because when you start coding, 90% of the time, you're going to have it in that spot.

So we need to open Revit. So we need to close this, we need to open Revit, we need to open Dynamo. So let's do that. So let's close this, find Revit 2019, and then just open a blank project because we're only going to get to Dynamo.

What we just did could be used in Dynamo Studio because it doesn't touch the Revit database. But anyway, so do that, and then-- whoops, whoops, whoops. Hang on a second, hang on a second.

Hold on a minute. Hold on, hold on, hold on, hold on. We forgot one thing. Hold on, open that back up. Hang on, hang on, hang on.

We forgot one thing. We made a fudge factor, but we didn't do anything with it, did we? I just realized that.

So our age is going to always be the same no matter what we put on the input port. So we're debugging it right now. So you've got to open it up again. I might have done this accidentally on purpose.

AUDIENCE: We'll never know.

MARCELLO SGAMBELLURI: We'll never know. So you've got to say minus-- what you think you've got a minus? Where did you got a minus? Why do you think you've got a minus? Anyone?

ALL: Fudge factor.

MARCELLO SGAMBELLURI: Fudge factor! And intelligent typing will help you. Now recompile, build. Please close Revit if it was open, please! Because if you can't compile this if Revit's open. I know, it's just the way it is.

I would actually recommend to say rebuild solution because if you actually kicked on that Revit database, it's going to wipe-- OK, redo that. Everyone go here to build, rebuild solution. It'll just clean all the dirtiness out of there-- rebuild solution.

Now let's go to Revit. Is everyone with me? How are we doing on time? We spent 30 minutes on this? That's OK.

Open a new blank project. Everyone add the fudge factor? Just add it at the end of age, age minus fudge factor. Rebuild solution. So I'm only opening up Revit so that I can get to Dynamo.

Now, we're going to be using Dynamo 1.3.3 for now. I kind of prefer it for now. 1.2 is coming out at the end of the year, so I encourage you to use that. But for now, we're just using 1.3.3.

We'll have a beer tonight, and I can explain why we're using 1.3.3. But we use 1.3.3. So 1.3.3, here we go. Oh, here we go. So start a new Dynamo.

Now, have you ever seen this Add button on the bottom? This Add button adds your zero touch DLL that you created. So pull that down and say, Import Library. You actually created a library, even though you didn't know it. A DLL Ls a library.

When you built a solution, it put a DLL in a default location. We're going to go grab it. So go ahead and say Import Library.

AUDIENCE: Marcello, you're computer's considerably faster.

MARCELLO SGAMBELLURI: Oh, it is? You want me to slow down? Does anyone have Dynamo open?

AUDIENCE: Yes.

AUDIENCE: Finally.

AUDIENCE: We're there.

MARCELLO SGAMBELLURI: OK. Add, Import Library. Is that slow enough?

Now just be careful here. Go back to the data set, go back to your 05 Get Age, go to Start-- go to Start, go to My Zero Touch Library, go to Bin, go to Debug, go to Date Modified, and it'll be sitting there for you. This is my Zero Touch Library DLL. This is the name of your project.

Why Default, Bin, Debug, blah blah blah? That's a default location. I thought it would be easiest for now. You can have a specific spot you want it. But this is where we'll be getting them every time.

AUDIENCE: [INAUDIBLE].

MARCELLO SGAMBELLURI: Yes? OK. So click that, and then say Open or OK. Now, in your library, you should have-- this should have popped in. My Zero Touch Library, that's the name of the DLL. Did everyone get that?

My Folder, that's the name of the namespace. Remember, the namespace is the name of our book. Everyone with me?

Get Simple Info, that's the name of our class. You remember that class is the name of the chapter? Marcello Age Node was the name of the--

AUDIENCE: Method.

MARCELLO SGAMBELLURI: --method. Do you see that? I mean, it even just follows the structure of what you just saw. Isn't that super cool? That is Zero Touch. Zero Touch, as long as you have a namespace, a class, and a method, it's going to-- it's going to put a-- it's going to create a node. Yeah? So go ahead and put that down.

Here it is, Yeah! I'm going to rollover here. Everyone ready? Ah, there's my age. Surprise out there, yeah! Surprised? Maybe not. So it's out there.

Super cool? Come on, how cool is that?

AUDIENCE: Whoo-woo!

MARCELLO SGAMBELLURI: Come on, yeah!

[APPLAUSE]

So let's test this input port. So, I don't know, go and double-click on here, I don't know, 10. Because we said minus, right? So there we go. Maybe we want to put a minus, I don't know. It depends on who you're talking to. I don't know. Cool, yes?

AUDIENCE: Yes.

MARCELLO SGAMBELLURI: Yes, OK. I'm going to do this now. Everybody now is officially Zero Touch programmers. Give yourselves a hand. Come on, now!

[APPLAUSE]

Yeah, I got something special for all of you. Don't worry, we've got seven more to go, but I thought I'd do it now. I've got special ribbons. Whoo, this was very difficult to do. It says, Dynamo Zero Touch Programmer for everybody. Yeah!

And these are the only ones made. So it's kind of like-- you ever watch Fight Club, you wear that ribbon, and you just go, I know.

[AUDIENCE LAUGHS]

So do you mind? So I just thought I'd do that to get everyone warmed up. It took about 30-- maybe just about 20 minutes. But everything else is going to follow this logic. So let's take the next example, but instead of finding Marcello is age, why don't we find the category of an element in Revit. What do you say?

AUDIENCE: Yes.

MARCELLO SGAMBELLURI: Yeah, OK? Let's find the category. Let's find the category. So go ahead and close-- I want everyone to always just get used to closing everything so we don't muck everything up. Close everything-- everything. So next-- is everyone having fun?

AUDIENCE: Yes.

MARCELLO SGAMBELLURI: Yeah! All right, it's going to get way better. It's going to get way better.

So this is the next one, Get Revit Category from Wrapped-- what does that mean? So this is ultimately what we're going to create. Do you see it?

What comes out of the output port is a category. What comes into the input port is a Revit element. Do you understand?

So we need to set up our output as a Category type. And our input port, we have to set up as a Revit Element type. Yes? And then we need to access the category out of the database so we can get the category.

Just like getting Marcello's age, you've got to first get to know the building, you've got to then get to know the element, and then you've got to get-- you have to ask. You know what I mean. You got it, good. So that would be exercise number six. So, let's do it.

So I want everyone to always start from scratch from here, number six Get Category Start, yes? This is how we're going to do it every time-- boom, boom, boom, boom, boom. Start Zero Touch Library. I named the solution the same on everyone. Click over here.

So now we should be a little bit more familiar with what's going on here. I took it upon myself to write some of this out because now you're all Dynamo Visual-- Dynamo Zero Touch programmers, yes? So I won't do it-- we won't have to do it all.

So you see what I did is I made a namespace, a class, which is a chapter of the book, and then I started the method for us. Public static, type [INAUDIBLE], and then you have to do a type. Remember we did int for age? You're like what's coming out of that output port? It's a category. So it's Revit, Elements, Category.

Revit elements, when you see this, it means it's wrapped. We'll get into that in a minute. What is this? Shout it out. Yell it out.

AUDIENCE: Name.

MARCELLO SGAMBELLURI: The name of what?

AUDIENCE: Node.

MARCELLO SGAMBELLURI: The method slash name of the--

AUDIENCE: Node.

MARCELLO SGAMBELLURI: Node, yeah. What's in here.

AUDIENCE: User input.

MARCELLO SGAMBELLURI: Input. So this is the name of the input port in Revit Element. Is that clear enough for you, in Revit Element? I don't know, you could choose whatever you want, but in Revit Element, I like to use that.

Revit Elements dot Element, this is another-- this is the type. You see it in light blue? That's the type coming in. Would you want to put that is int? Why not?

AUDIENCE: Because it's not [INAUDIBLE].

MARCELLO SGAMBELLURI: Right. C#'s very type-based. It's like telling-- it's like telling-- if we did the last example, it's like saying, what's five plus blue? I don't know what five plus blue is. Those types need to match up. So you understand?

So it says, add code here. Let's do it. So instead of typing friends, we're not going to do that. Instead of typing friends, we're not going to do that, we want to access the Revit database. So, I already loaded in the DLL of the reference.

So, do you see what's coming in is the In Revit element. So that's what we need to access. So we type here In Revit Element.

Why do we type In Revit Element? Anyone? I'm going to walk you through this a little slow. Why do we type in In Revit Element? That's what's coming in.

Isn't that what we want to access? Do we need to access the entire Revit database? No, because in this situation, we're allowing the user to put in an element. So once that element comes in, we grab it, we make friends with it, and then what's that magical thing that we press?

AUDIENCE: Periods.

MARCELLO SGAMBELLURI: Periods, so do it. Watch this goodness that pops. [GASP] I could get bounding box, curves, faces, ID, name, all the parameters? Sonnets, oh my gosh! I'm having myself a party. Yeah?

So for this case, we just want Get Category. Yes? Get Category. We want to close it. That's it. That's all.

Now, one more thing I have to mention, I actually had this prop, but I couldn't bring it. I had this big present. So it means wrapped. This is how it works.

I had a prop, but now I've got to do interpretive dance. This is how it works. So the way Dynamo works with Revit is any Revit element that is shown in Dynamo, which would be like the Revit element that-- you know you say select model element, That is actually placed in a wrapper of Dynamo. So, you have a wrapper, a Dynamo wrapper, around your Revit project basically. So whenever you want to send it to Dynamo, or you ever want to read things with Dynamo, it has this wrapper on it.

Now, there's certain things on the wrapper that you can see. One of them is the Get category. So we have not unwrapped this. The developers were kind enough to put a wrapper around the building.

And why do we have a wrapper? We'll have a beer later, and I can explain why there's wrappers on Dynamo elements. But, there's a big wrapper.

On the wrapper, someone's Sharpied on Get Category. And someone else Sharpied on other things, like bounding box. So there's a few things you can get on the wrapper. So we have not unwrapped this. It is still wrapped.

So the way you-- the way you look at things on the wrapper is you just take the raw element that comes in from Dynamo, which is wrapped, you press Period, and you see all the things that are on the wrapper. You see, we're only seeing things on the wrapper. What does that mean? Later, we're going to take off the wrapper, and we're going to see thousands of more things.

So for now, the category happens to be on the wrapper, so that's why it's called wrapped. Got it? So then all we need to do is what? Anyone? Just like we got my age, what do we need to do?

AUDIENCE: Return it.

MARCELLO SGAMBELLURI: Return it. So we could make another element, an object, but let's just type Return here. Hit-- please have Revit closed, please, and hit Build Solution. It's should say Build Started and should say "succeeded."

Now, do you have to-- every time you code and compile your C# code, do you always have to have Revit closed? Yes. Do you always, when you want to check it, do you have to open Revit and open Dynamo? Yes. That's probably the disadvantage of C# versus Python.

Python, you can code on the spot and hit Run. Anyone Python users? But I'm not here to compare the two, I'm just saying. So if you don't like it, deal with it.

[AUDIENCE LAUGHS]

So cool? So you're going to start to get the hang of this. Close that where you actually look. Now this one, go back to your data set.

Now that we're doing the Revit API, go to-- I have pre-baked Revit files for you. So this one says Get Revit Category Wrapped Start. Just double-click on that. I'm trying to make it as easy as possible for you because coding in a lab, it's not always that easy. So I want to make it super easy.

So, did you see what I clicked on? I went to the folder, Get Category folder, I clicked on the Revit file that said Start. And we have a wall in here already. Lab assistants, could you make sure you should see a wall on everyone's screen?

AUDIENCE: Revit's still launching.

MARCELLO SGAMBELLURI: That's OK. That's OK if it's still launching. I'm going to move a little bit ahead. I know these are the frame computers. They're a little slow. I apologize in advance. But don't-- we've been having issues with the frame computers just on the speed. And so don't be giving me a bad mark because of that.

[CLASS LAUGHS]

That's out of my control. So here we go. I'm just going to-- I'm just going to move ahead and go Dynamo because this is all going to be systematic as we move through the next 50 minutes of class.

So open up Revit. In that folder, open Dynamo, say New, go to Add, Import Library, and then go back to the data set, go to number six Get Category, and go where it-- put it in its default location, Start, Zero Touch, BIN, Debug. I always like to hit this Date Modified. It bubbles to the top.

And I always, I always, I always check to make sure that that DLL has been updated. I always check to make sure that DLL's been updated. So it should be about around the same time.

Holy smokes, did I have a monologue for three minutes? Gee, that's crazy. I see you did it-- I see you did it at 11:09. It's 11:12, jeez. That's the name of our DLL.

Also if you build a package-- by the way, so you see how we're loading a DLL every time? You don't have to do that. But this is an intro course. So I'm just showing you how to load it in every time. Because when you start coding, you'll probably do little things.

Eventually you'll get to be building your own package, and you can bundle it up in a package, and you won't have to do this every time. Do you understand that? Just for now we're-- we're intro.

So My Zero Touch Library is the name of the DLL. It even says DLL on the far right. Then you come over here and, you remember, My Library Folder is the name of the namespace. Get Revit Elements, I changed the class name, because it makes sense. Get Revit Elements, that is the--

AUDIENCE: Class.

MARCELLO SGAMBELLURI: --class, or the chapter of our book, Get Category here. Now go ahead and use the selection node so you can select the wall. Because this is not-- oh, this is a good point. Hang on, I got this.

And I am going to give you-- I'm going to give you a-- I'm going to give you a copy of my book if you can answer this question. You've got to raise your hand, though. Don't yell it out. I wasn't going to do this. I don't like to give the handouts.

But why is that not running automatically? Hands. You, sir, over there.

AUDIENCE: It's because we didn't set the default.

MARCELLO SGAMBELLURI: Didn't set the default, yes, very good. So by the way, we'll get this. Don't worry, you'll eventually get-- these copies are all available to download online. Just print it out in color in your office and just say it's for work.

[AUDIENCE LAUGHS]

So thank you, thank you. So you understand? So nothing's happening. We didn't put anything as a default, so we need to load something in.

So just go ahead and do Select Model Element, Select Model Element, Single, and then select the wall. Whoops. Select the wall and then what should the answer be?

AUDIENCE: Categories.

AUDIENCE: Walls.

MARCELLO SGAMBELLURI: Walls. Oh yes! Oh, I'll tell you what, every time-- I get-- I get misty every time I do this. So we just accessed the Revit database. How cool is that?

AUDIENCE: Woo-whoo!

MARCELLO SGAMBELLURI: Ya! Now remember, that's on the wrapper. Why don't we unwrap this thing and see what other goodies are inside of there? What do you say?

AUDIENCE: Yeah.

MARCELLO SGAMBELLURI: Yeah, OK. It's really fundamentally easy. And we-- how is the pace now? Good? You're getting a feel for how we're-- we're just--

AUDIENCE: It's slow.

MARCELLO SGAMBELLURI: How's the piece?

AUDIENCE: Good.

MARCELLO SGAMBELLURI: Better? OK. We got 45 minutes? Awesome. Close everything. How about we unwrap-- how about we unwrap, but this time, you know what's inside-- whoops-- you know what's inside that wrapper?

AUDIENCE: [INAUDIBLE].

MARCELLO SGAMBELLURI: You know what's inside that wrapper? Inside?

AUDIENCE: Everything in your project.

MARCELLO SGAMBELLURI: Everything else. How about the element ID? What do you say? Eh, I want length. OK, fine. You go get that at home. But we're going to do ID. Once fundamentally you get it, then you're ready to go. Yes?

AUDIENCE: So how do we know what is on wrappers?

MARCELLO SGAMBELLURI: We'll get there. How do we know what's wrapped and unwrapped? That's-- good question. So let's do it. So just so you know, this is what it's going to look like.

So just systematically, we're going to be going back to the data set, wherever it is. We'll go to the next one. Get ID, number seven, Start, Zero Touch Library. You don't need to see my screen. I think you'll get the feel for it. And then you've got to click on this class over here.

By the way, does it seem difficult to anybody yet?

AUDIENCE: No.

MARCELLO SGAMBELLURI: Do you need a degree in computer science to do what we just did so far? Maybe? Maybe? Well, this is an intro course, remember. Let's unwrap that thing.

So on the outside, remember, it's Sharpie. There's Get Category, there's bounding box. There's a few things, but that's all kind of boring. Let's unwrap it. The Dynamo wrapper around our Revit element, let's unwrap it. How does that work?

So, the way it works is it works just slightly differently for the setup. So I created a public method for you already, Public Static. Now, what we're sending out is the element ID from an unwrapped element.

So when a Revit element is unwrapped, it has this Autodesk.Revit.db and then element ID. That's how it is. It's basically-- you just have to know that. So Autodesk.Revit.db means it's unwrapped. When it says Revit Elements, it means it's wrapped.