Learn how to install Fredo6's Bezier Spline and LibFredo6 and tour the functionality offered in the Bezier Spline toolbar.
- [Instructor] Here, I have the SketchUcation Extension Store installed. I'm going to open that, and search for the term Bezier, and install the Bezier Spline script by Fredo6. I'll click Yes and OK, and then I'll open that toolbar right here. Now, this script works only partially.
You'll find that some of the tools don't function properly, and that's because Fredo has authored a separate library plugin that works with many of his scripts. So if we want this to be fully functional, we also have to install LibFredo. Here it is, LibFredo6, install. And again, click Yes and OK. And then I'll close the Extension Store. So the library doesn't really show up here, on the toolbar, or anything, but it does enable this to work.
So for example, if I click this tool here, a dialog box should appear. Without the library, it doesn't work. You can also access that up here, under LibFredo6 Settings, and incidentally, in here, you can check any Fredo6 plugins that you have installed for an update, and you can see if they're the most current versions. These are up-to-date. Now let's start by examining these tools, here.
And they fall into basically two categories in my mind. They're the curves, and then the straight lines. So let's start with the straight lines. This is a poly-line, and the way it works is you just click points, double-click to end, and that puts you into editing mode, and then you can position the cursor over these control points, and you can reposition them, or double-click to remove, or double-click to recreate new control points, and that gives you a lot of flexibility in terms of being able to edit that.
Also, there's another subtlety that you should be aware of, and that is that when you want to move a control point, you can drag it, but that's just arbitrary. If you position the cursor over a control point and press the Option key on the Mac or the Control key in Windows, that will change this to a hollow control point. Can you see that? Now it's hollow. When it is hollow, I can use the arrow keys on the keyboard to specify which direction.
So if I press the left arrow, it'll be the green direction. That will only allow me to move that in the green direction. If I press the right arrow, it's the red direction, and if I press the up or down arrows, I can move that out of the plane of the red-green plane, and pull it up in the blue direction. So this is really the key to making three-dimensional poly-lines. Now I'm going to click outside of that to end the editing mode.
You can re-edit an object by selecting it, and then clicking on this button, right here, and that takes you into editing mode, where you can make changes, and then you can click outside of the object to close it. There's also a right-click menu that you can use to undo changes, or to toggle different things on and off. So for example, I can close the loop with a line. That will draw a line from the start to the endpoint, and you can toggle that on and off over here, or you can close that with a curve.
Now, in this case, because this is a poly-line, the curve doesn't work, but it does with the other tools. Let's move on and examine another tool here. This is the animation curve, and what this does is it will create a poly-line that has segments along the line that are controlled by these minimum and maximum step lengths, and you have different ways of placing those points down. This tool, here, allows you to make a poly-line that has filleted corners.
So for example, I'll try that, and you get this dialog box. Let's say I want to have six-inch fillets, so now, when I draw that, you can see the fillet there in the cyan color. I'd like to make those larger, and you can do that by either pressing the Tab key, or by clicking on this icon, and then you can revisit that dialog box. Let's say I want it to be three feet, and that changes them all on this poly-line.
So that can be helpful. And then there's also these specialized tools, such as this one, which puts intervals on your poly-line at whatever you set. So if I say every three inches, then when I draw that poly-line, there's going to be little points along there every three inches. Here we have, these two tools are kind of similar, and the way that they work, let's put in three feet. The way that they work is like this, where it puts in this kind of giant arc transition between the segments.
And this one works in a similar way, but the arcs are in slightly different places. So I'm going to erase all of that. Let me just draw in a shape here, and I'm going to draw that in. The third point that I click no longer has that ability to use the snap. Basically, I can't draw that horizontally or vertically, but what I need to do is press the Option key to go into that hollow mode, and once the control point is hollow, I can then draw that in, and I can essentially use something like Ortho in AutoCad.
It allows me to draw lines orthogonal to the axes. I'm going to double-click here to end drawing, and then click again to exit the command. Now, what I'm going to do is make a group out of this. I'll choose Edit, Make Group, so it provides a container, and then I'm going to use the move tool and just copy this over, let's say, four times. And then this will provide a kind of structure that we can use to take a look at these curved commands.
So for example, here's the classic Bezier curve, and the way that it works is you click the start point, and then the endpoint, and then you go back and click the intermediate points one at a time, like that. Now, you don't have to do it that way. What's interesting is I can start, instead of going to the endpoint, I can press the Shift key twice, and that changes into this mode, where I can then click the next point.
So that's just an option. Each one of these curves is defined by a different mathematical algorithm, and so the end result that you see is segmented. So it's controlled by the precision. Right now, it says 20 segments. If I say 50 segments, by typing 50 S, then those segments will kind of disappear, although they're much smaller now, and you have to really zoom in to see them. If I just say five segments, 5 S, you'll see it looks really blocky.
I'll go back to 50 segments. Now, this is how you can control the complexity of the objects that you make. This gives you certain flexibility in creating curves. And then a similar tool is right here, the uniform rational basis spline. It's similar to its cousin the NURBS. Now, you may have heard the term NURBS in other programs, but this is an URBS, it's a uniform, rather than non-uniform, it's a uniform basis spline.
And you can set in the degree that you want here, or just use zero, and it will be automatic. I'm going to use zero, and then I'll draw that in just by clicking on these endpoints. You can see that the curve has a slightly different shape as compared to the classic Bezier, and of course, its curvature is control by the position of the control points. But if you add additional control points by double-clicking on this lattice, what happens is the curve gets closer to the lattice.
So in this way, you can control the shape of the resulting curve by adding additional control points. Now, these two, I'd say, are very similar in the way that they function. Now, all the others are also similar, but they're grouped separately. So for example, let's look at this one here, this is the Catmull, and you can see that the icon represents that there's control points along the curve. So if I click these points, you'll see that the curve goes around the structure, rather than weaving between it like the others.
You see that? So it's kind of in a different category, essentially, because the control points that you click are going to definitely be on the curve, whereas these are not. The only control points that are on the curve are the start and the endpoints on these two. So that's the Catmull. There's also the cubic Bezier. When you create one of those, it looks similar to the Catmull, but it has a slightly different shape.
It bows out a little more. And finally, there's the F-type, which is similar to the cubic Bezier, but the advantage of the F-type is that the number of segments increases in areas where you have more curvature. So notice that the segments are more spread out here, where it's less curved, and then there are more segments in here where it's more curved. That's the advantage of the F-type.
And with all of these different types, you can always edit them by right-clicking, and you can change the precision. So I'll type 50 S, and it'll give me more segments there. So that's basically the mechanics of how you use these different tools, and on each one, you can select it, right-click, edit that, and then you can either close it with a nice curve, or you can close it with a straight line, if you want. You can also toggle off the display of those segment points.
I think you have a kind of a good feeling now, hopefully, of how you use these different tools.