The name of this video is 2D surfaces example 1. Let's look at how we can create geometry with this system. If we look at our lower left hand corner here, we'll identify a structure that should seem pretty familiar to us by now. Again, I recommend making something like this for yourself, so you can figure out your pseudo coding from that organization. But what we have again as i, j structure. I've drawn in this polyline connecting the corners of the matrices just to clarify the module just for visualization purposes. You work with this, figuring out manually again, what geometry that you want to create. I got to do something pretty quickly here. If I use a control point curve and draw between these three points, I could create this potato chip shaped surface. The fact that I used three points to do it makes it flat even though it's a curved surface. Which means I could use something like planar srf to create a 2D surface from that. I could do that for both sides. The other thing I want to point out is that I drew the curve in a counterclockwise fashion, which creates the front face facing up, and my back face on the bottom. Again, directionality of the points makes a big difference if I had happened to draw that the other way in a clockwise direction. Then it would have my back-face facing up. This is important for a number of things when you're creating this much geometry. If I was going to unroll this geometry, it always unrolls with the front face facing up or if I was going to extrude, it's going to extrude in a positive direction from the front face. So there's a number of important factors that concern the directionality of the face. Then also we're going to see in the next section of the lesson when we're dealing with vectors and 3D constructions, that back face, front face relationships are really important. I want to be cognizant of that direction when I input the sequence of points into my code. So we'll take a look at that. This is the code from the last lesson. I don't need to label my points anymore here, so I can comment that out. Then I've added another loop here to create my geometry. Go back here, let's hide that for a second, and then I'm just going to delete this stuff here. Bring your surface back. Let's go back to our code. I'm going to create the first curve, that I'm calling curve01. I've written out, I wrote out the pseudocode, so the points I'm going between starting at negative one, negative one down here. Again I go in a clockwise i, j, i minus 1 j, and then back to this one to close that curve. Then do something similar for the second curve. Starting at i, j and then going to i minus 1, j minus 1, and here and back to here. Save those curves, those ideas, and these variables and then I just make a planar surface from the curves. I'm going to do that as a, if I leave the degree out, it'll default to a 3-degree curve. Let's run that. It's creating that geometry on the surface. Then I could also, oftentimes when we're using a surface as a generator, after we're done with it, we don't want to see it, although we don't necessarily need to delete it, we could just hide it. So hide it in the main. After we're done selecting it, that idea is still available to the code even though the geometry has been hidden. We run that one more time, and it's creating that geometry now on that surface. Now if I wanted to close triangular surface, I could set the degree of my curve to one. That's going to create a polyline triangle. Now it's going to give me a closed triangular surface. Of course, with this system you could play with the number of intervals. If I really reduced it, let's say three and three, it's still going to work fine, but it's going to create a chunkier triangulated surface. In the next example, I'll show a slightly more complicated geometry. Taking something one of the examples from our 2D patterning code, and show a different technique for making a surface out of it.