 All right, so first things first what I'm going to do is I'm going to drop down a geometry node So I'm currently inside of the OBJ. That's the the root most area inside of Houdini here So what I want to do is hit tab on the keyboard All right, that brings up my tab menu and start typing out geometry Now what this allows me to do is it allows me to create a node that contains geometry It actually can contain quite a few things, but for now just to keep things simple and basic Let's just look at this node as a container for geometry. Okay And what I'm going to do is I'm going to double-click on this name and just call it wood Or we're going to call it tiling wood planks because our wood planks are going to tile Okay, perfect. So then what I want to do is I'm going to double-click this Okay to jump into the node and now if you want to use the keyboard Hotkeys for this you can use the U key to go up and out of a node or the I key on the keyboard to jump in So it's I for in you for up. All right, because we're navigating a network hierarchy right here Okay, cool. So inside of here what I'm going to do is drop down a grid All right, and this grid is going to turn into Magically into wood planks. All right, so a couple of parameters I want to set up on this particular grid here. I'm going to leave the size of 10 by 10 now You can leave it at any size you want But when we do need to take these sizes into account I'll point it out so that way you know to adjust it to the size that you said it But I would highly recommend just sticking to 10 until you see, you know, this entire technique To the end. All right, so let's type in two and two for the rows and columns and now that will give us just a Single quad right there and what I really want to do is I want to increase my rows now this Slider here is going to become the slider that allows us to control how many rows of planks we have Okay, so let's just keep it at 10 for now or maybe a little bit more. Let's do something like 12 make some small planks Okay Cool. So with that what I want to do is now I want to go through each one of these particular primitives here All right, and I want to do some sort of operation to them now to do this It's really easy inside of Houdini. We can drop down a for each loop and a specific type of for each loop So I'm going to tab again on the keyboard and what I'm going to do is type out for each and Select the for each primitive. Okay. I'm gonna wire this guy up there Like so and turn on the blue display flag For the end there. All right. Now what this allows us to do let's talk about the for each a little bit more Okay, so what this allows us to do is it allows us to loop through each primitive now inside of Houdini a primitive is a Face so if you're coming from like my r max or any other 3d package It's the triangle or it's the face. Okay, so anytime you see a solid piece of geometry That's a primitive inside of Houdini and we can always look at the number of primitives We have or the current ID for a primitive inside of Houdini by hitting this little flag right here to display the primitive numbers Okay, and you can see that it starts at zero and goes all the way up to the number of primitives that we have So in this case, we have 12. All right, it starts at zero one two three four five six seven So on and so forth. So we have 12 primitives here And what we can do is we can loop through with this for each loop right here We can loop through each one of those primitives Okay, so what I'm going to do is I'm going to turn on single pass just so we can see this in action So now I have the way the ability to look at each primitive individually All right, so I can see the results of the operation and inside of this loop here. What I can do is I can perform some operations on every single Primitive individually all right, so if I were to do this without a for loop I would have to figure out a way to process each one of these Planks here are these pieces of geometry these primitives All is one piece of geometry, but the for each loop allows us to go over each one Okay, so the the thing that I really want to do is I want to add some more divisions right here All right, this will be the last thing I do in this particular Elector, so what I'm going to do is I'm going to drop down a group node Okay, now this group node allows us to group geometry. So I'm going to give it a name I'm going to call this the borders like so All right, I'm going to turn on the display flag for that and now you can see that I actually have a default Set up in my particular version of Houdini here What I've done is I've gone in and set dollar OS now that just stands for the operator string So whatever I named the actual node, it's going to use that name of the node for the actual group name, okay? Hopefully that makes sense and to make it default What I did is I I typed it all in and I set all the settings the way I wanted And I hit this little cog wheel up here and I said save presets But you can also say save as permanent defaults So when you do that every single time I create a group node over here All right, it comes with that preset Cool. All right. So now we have this borders in here Okay, and this borders is going to look for some edges and I'm looking for border edges But specifically I want this bottom edge right here. All right and this top one So I'm gonna hit s on the keyboard and I'm just going to highlight these for you guys I'm not gonna select them. All right, just turn I just hit the s key just to enter into the edit mode okay, and So I want to select both these guys. All right, but I don't want to do it manually I need to do a procedural. Okay, and that's just because I have a thing for proceduralism and everything's got to be procedural You could totally just go manually select that but let's look at the procedural way. Okay, so let's go and Turn on a specific feature in this group create node. So I'm gonna turn on the Keep in bounding regions. All right, and what I want to do is I want to get this little blue box into the middle first of this Primitive that we see here. So what I want to do is I want to utilize an expression Okay, and inside of Houdini we use expressions to create procedural relationships. It allows us to take data from other nodes and Set the values. All right. This is really at the core of a lot of the proceduralism. So what I'm going to do is I'm going to use the centroid Function all right, and I'm going to type in zero for the first argument now you can see that We get this little IntelliSense pop up here and it gives us examples of how to use this particular node or this function I should say and What it's looking for is a string and a float. All right. Now you may be wondering why I just typed in a zero All right. So if we look at the example here, we have a string Which is pointing to some path to a node that exists inside of Houdini here, and we have this Variable that corresponds to the components of the centroid. So the centroid of a primitive is its center Literally it's center in 3d space. Okay So what I want to do is I want to actually pull in the data That's coming into this first input right here, and that's why I put in a zero Any time you put in a zero it'll pull in that First input geometry Cool. So now let's just use DX for the X component. All right, and let's Select all of this and let's go into the Z component and let's type in DZ All right, now you can see that we've centered up nicely on this guy now because we don't have any, you know Y Value in our grid here this particular prim We don't need to put anything in but you could you could go in in here and just type in D underscore Y Like so now it's centered up perfectly So now what I want to do is I want to make this thing just a little bit wider And actually it's if you look at the top view so it's base bar two on the keyboard or you can just hit two To swap between all these guys. All right, so it's one two three four get to all your views All right You'll notice that the box is actually overlapping, but just for Completeness here in this course what I want to do is I want to set this box the size of this primitive So to do that we're going to introduce another expression function So I'm going to use the BB box Function again, I'm going to type in zero because I want to take in the data that's coming into this first input right here Okay, and this time you can see that the variables that it's looking for is DX min D Y min Z min Z max all those cool features and values that are very useful in procedural modeling So what I'm going to do is I'm going to use the D Z size Like so and now we have a box that is perfectly The same size as our primitive So what we can do is just add on a little extra So I'm going to say zero point one so plus zero point one so you can see how we can build up these expressions So if the size of this primitive ever changes This box will change too. So now we have a fully procedural system of selecting edges now You might notice that our edges aren't actually selected Okay, and that's just because these edges are partially contained inside of this box So we just need to turn that guy on right there And we need to make sure that our group type is set to edges as well. And there we go So now if I were to ever change the size of those guys All right, so let's say we add more and let's actually hook this into the the for each loop so I can Look at all these There we go. So you can see it's always selecting it. So we can always change this stuff You got to update that. All right, so fully procedural edge selection right there All right, so let's go back in our perspective view like so and what I want to do is add some divisions because I want to make You know individual planks and in here. So I'm going to use that group that borders group Another little tip to you can hit this little guy right here and you can view your book your groups All right, so it gives you another way to visualize where your groups are or what your groups contain Cool. All right, so let's go and drop down an edge divide node like so Very cool wire that in like so and let's use that group. So I'm going to say let's use that borders group Okay, and you don't see anything just yet. That's really weird. So let's go and say connect points Voila because this division is a set to two we get the division They're right down the middle there now It might be easier for you guys to see if I go and turn the background to dark So I just hit D on the keyboard Selected the background tab and selected dark Let's turn off the grid There we go, and you can see we have a new edge and we can go we can add more edges Beautiful, and that's exactly what we are looking for Okay, so I'm going to close out this lecture here and in the next lecture We're going to take this even farther and start to get our wood planks all situated