 Alright, so let's move on to creating a tool that allows us to scatter a bunch of these guys around some sort of terrain or any surface really inside of Unity. And so what I'm going to do is I'm going to utilize the Houdini engine to give me this power because what I can do is I can create an HDA here inside of Houdini and import it into Unity and it'll work just like if I had actually programmed my own tool inside of C sharp or something. Okay, so really really powerful which is why I wanted to show you know this complete process from creating you know a grass blade texture to creating a clump to scattering it to exporting it and now finally to actually scattering a bunch of these onto a surface. So let's go and create some sort of geometry node here. Alright, and what I'm going to do is I'm going to call this just a, I'm going to call this something really simple. So let's just call this our IP terrain. Let's actually spell that correctly. We'll call that terrain generator something like that. Alright, and what I'm going to do is right click on it right away and I'm going to create an HDA out of this. Okay, or Houdini digital asset. And I'm going to adjust these names because this is going to be the label that you see when you create this. Alright, and we're going to destroy all spare parameters. Alright, so what we get is the edit operator type properties window. And this allows us to basically interact with all of our HDA properties if you will. So we can go and create our own custom user interface. So for instance you can see that our current geometry node you know has these tabs up here for its properties. Well I don't want to see those. So I can go in here in the parameters tab here. Right, I can go in here and I can select all these guys and I can say invisible. There we go and that actually wipes out the UI. And we can go and then and add our own UI. So if I just drag and drop any UI element from this side and into this side and hit apply, you can see now I have a float value. Alright, and I can use this float value to feed into my actual terrain. So what we're going to do is I'm going to call this the terrain size for the name and then terrain size for the label. And this basically is going to be within a range. So I want a minimum size of 10 and maybe something like 100. Alright, we're going to try to make a pretty large little grass field here and I'll set this to something like 30 by default. Alright, so I'm going to hit apply and accept there for now. Now there's so much more to know about creating HDAs and it's kind of out of the scope of this particular course, this little mini course. I do have plans to make it more of a mega course if you will. It'll walk you through beginning to end on everything you need to know about Houdini Engine with Unity. But for now, I would just follow along with the steps here. Alright, so what I'm going to do is I'm going to jump into that geometry node there and I'm going to create a grid. Alright, here's this grid right here. Awesome. Alright, so what I want to do is I want to attach the slider that we created up here to the size of that grid. So I'm going to right click on it, say copy parameter, jump into my terrain generator and just paste that in for the x and y size here. Cool. Alright, we also have control over the resolution of this particular piece of geometry. Okay, and so what I want to do is I want to actually tie, I just want to use one slider to change the resolution because I want to keep all the polygons perfectly square. So I'm just going to right click on rows here, say copy parameter and then paste relative reference. So now all I have to do is just, you know, slide one slider and I get resolution. And every single polygon or primitive here is the same size. Alright, cool. So let's actually promote this parameter up to the top of our HDA. So I'm going to right click on this and say type properties. I'm going to jump back in now to the node and I'm going to hold down alts and middle mouse click and that will then promote that to the parameters, our type properties up here. Okay, so I'm going to apply and accept that and now you'll see that we can control our rows, our resolution here. So if I hit W on the keyboard, I can go to wireframe mode. That allows us to control the resolution from the top here. We can also control the size all at the same time. So cool stuff. Alright, so I'm going to disable the display of my skylight there and hit W on the keyboard so I can get back to the non wireframe mode there. Okay, so let's go back into our terrain generator. And what I want to do is just give this some basic noise. So I'm going to say mountain for a little bit of noise. What this will do is it'll allow me to create, you know, kind of a little grassy null, if you will, with, you know, some nice little undulations in the terrain and stuff like that. Okay, so maybe something like that and maybe a little bit bigger, maybe switch over the noise to a sparse convolution here and then increase the height a little bit more. This way we get some mounds and stuff like that. It'll look cool inside of Unity. Alright, cool. So I think that's going to be good for a default right there. Alright, and then one last thing I really want to do here is I want to be able to colorize this by its current height values. And so I'm going to drop down an attribute wrangle node here. And what I'm going to do is call this my colors. Like so. Alright, and so what I need to do is I need to find the minimum and maximum size. So if I were to go to the side view here, the front view, I need to find the distance, you know, from our maximum point down to our minimum point and then basically create a gradient between all the points y heights here inside of this grid. Alright, and so to do that, what we're going to do is we're going to create two vectors. So I'm going to call this box min and box max. Okay, and then I'm going to pass that into a get BB box function. We're going to get the bounding box information from the first input or input zero right there. And then I'm going to pass that into box min and box max. Like so. Cool. Alright, and so then with that, we now have the information about the minimum and the maximum y of this particular grid. And so what I can do is I can actually create a ramp value. Alright, so I can say float gradient alright is equal to our fit. And we want to fit our p dot y between our box min dot y and our box max dot y and we want to fit that between zero and one. So wherever it's, you know, at its minimum, we'll get black wherever it's at its max, but we'll get white. Okay, so we can verify that now if we pass that gradient value into our color like so. Voila, pretty cool. Okay, so then with that, we can now override the colors. So actually I should just leave that there, but this time I want to utilize a ramp. So I'm going to create a new ramp here and I'm going to call this our colors and I'm going to pass in that gradient value for our zero to one value. Okay, and so what we need to do is hit this little spare parameter button and this allows us now to control the color. But you'll notice that this particular ramp right here is just a single float value. I need to actually turn this into a color ramp. All right, so to do that what I'm going to do is I'm going to go hit this little gear up here and then select edit parameter interface and inside of here what I want to do is I want to select my ramp value. You can see it's currently set to float type. So what I want to do is I want to set to a color type. So with that all we need to do is hit apply and accept and now we can control the colors because I want to give the top kind of a grassy look and then maybe as it gets down into the lower areas it becomes a little bit more dark like a dirt. Maybe more dirt is exposed there or something like that. We can clamp it up a little bit. Not going to be pretty good I think. Cool. All right, so with that we are good to go. So I should put a null node. I should also say this is not necessary but I like to do this because it's a lot easier to find these particular nodes when you're doing a lot of object merging. So I'm going to say out turret. I'll capitalize it too. Cool. All right so now we got that all set up and one last thing we need to do here before we test this out in Unity is to promote our ramp up to our HDA. So I'm just going to open up my terrain generator select the attribute wrangle that's handling all of our colors and hold down Alt and then middle mouse click and that'll put our ramp or color ramp into our HDA properties. All right so now we're good to go. So you can see now we can control our terrain size and our resolution and our colors from the top of our HDA there. Excellent. Very cool. So I'm going to right click on this and say save node type and I'm going to jump over into Unity here because what I want to do now is test this out in here and that this is only possible because I do have the Houdini engine installed and I'm currently using Houdini 17 and Houdini engine version 3.2. All right so you need to have at least an indie license for this to work too. Okay so let's go into our Houdini engine tips and we have our HDA folder here and what I want to do is I want to open this up. I actually want to open up this folder so I want to right click on this and say show an explorer. There we go and then I want to go to my documents folder and go into my Houdini 17 folder and that's where my OTL is going to be or my HDA I should say. So I'm looking for the IP terrain generator. There we go cool. Okay so now we have it inside of our Unity project so let's just drag and drop that into the scene. All right so there we go. So now we have a pretty large terrain here and see that our grass close is actually pretty tiny compared to that. And that's probably because when we go and export things out of Houdini we need to basically multiply it by 100 here. There we go. There we go. That's a little bit better. I think it's a little bit better. Look at what this is going to turn out to be like. So we have our terrain generator now and we can go and we can change the size, we can change the resolution you know it's whatever you want. Go ahead and change these colors. It came in a little dark here. I'm going to change that spacing so you have full control over all these particular elements here. So let's do this and just kind of brighten it up a little bit. There we go. That'll be cool. All right so now that we've got that let's move on to getting our particular grass club scattered onto the surface here. Thanks so much.