Loft Generator Demystified: Loft Caps Tab

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  • Duration: 07:46
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  • Made with Release: 19
  • Works with Release: 19 and greater

In this Video, we’ll take a look at the Loft Generator’s “Caps” Tab. Most of what we’ll learn can be applied to the same settings of the other three generators, Extrude, Lathe and Sweep



In this video, we are going to talk about the generator objects Caps tab. This Caps tag exists in all four of the generators, the Lathe, the Sweep, the Extrude, and the Loft. Because we're talking about the loft, I'm going to show you how it works here, it's identical to all the other generators. By default, all loft-generated objects have a cap for the start and a cap for the end. If I turn off these caps, you will see that my object becomes a hollow skin. Fantastic. So what other settings do we have? If I put this on Cap mode for the top and go underneath, you'll see it's open underneath, and I can cap it on the bottom as well. So we can control the top and the bottom cap. Not only can we control the cap, but we can control the rounding. I'm going to go down here where it says Fillet Cap, and you can see now we have this weird linear embossing thing going on. If I increase the steps, you will see that it starts rounding, and I can control the radius from the Radius value. The type and radius and steps for the top and bottom can be different, as in this case here. We have a Fillet Cap on the top, and only a cap on the bottom. If for any reason I want to have just the fillet, I can select that, and now I have the fillet without the cap. Great. Let me just set it to Fillet Cap again. Now there are a couple of things that you need to be aware of with the cap radius. As you can see, the cap itself always retains its size. The best way to see that is to go to the top view, and make sure that we are set to grow shading lines. Now, you can see that this is my cap here, and this outside here is my rounding. And if I select this and start making the radius bigger, you will see that the cap retains its size, and the rest of the model grows. That is all nice and dandy. But what if I want the model to stay the same size and I want the cap to get smaller with each iteration of a growing fillet? Well then, we go down here where it says constrain. If I click on constrain, now, as I increase the radius, my overall model stays the same, and the cap gets smaller. Now, this is good but has its dangers. Let's go back to the 3D view. Let me show you what I mean. Let's assume that I select the circle and create some sort of concave surface, because here, we have an ideal situation. I'm going to press C to make my circle editable, then go to the Points mode and select the point over here. If I start moving this, you will see that once this curvature here becomes tighter than the actual curvature of the radius, our polygons start overlapping, and thus, we get what's called bad geometry, bad geometry. Yes. So what you need to be very careful with is when you use your Constrain switch, make sure that either the radius is small enough so you don't get these overlaps, or that the shapes you're using don't have very tight curves. This usually happens when you use text splines into any generator, and you create constrained Fillet Caps. Let me revert the model to its original state and let's continue. As you can see, my caps are made out of all these oddly shaped triangles. And if the question is, "Can I change that?" The answer is, of course. With the Loft Generator selected and the Caps tab selected, if you go down to the type, which refers to the cap type, you will see it's set to Triangles. I can set this to N-gons, which creates one huge n-sided polygon as my cap, which looks really, really clean and nice, or I set this to Quadrangles. Now, what this tries to do is use as many four-sided polygons to create my cap. Well, that's not always possible, and it doesn't mean it looks better. But when you turn on the Quadrangles and you set the Regular Grid to on, then with this number here, you can control what is the largest little four-sided polygon that is going to create your cap. So you can rest assured that this polygon is a 10 by 10 centimeter, four-sided polygon, the same for this, and this, and this, and the rest just go and connect themselves to the sides. If I make this small, you will see that I'm increasing the resolution of my cap. This is very useful when you are using your generated object with deformers. And if you search Cineversity, you will find a video about this. I will link any relevant videos in the description text below. For now, I'm going to set this to N-gons because I like it that way. And let's continue and see what we have here. The Hull Inwards and Hole Inwards are relevant with the extrude generator. So I'm not going to be covering them right here. We saw what a constrain does, and the create single object is very interesting. If I select this whole thing and press C to make it editable, you will see that I'm creating a hierarchy with my main body and two caps. Let me undo a few times to go back to my generated object. If I have Fillet Caps and press C to make it editable, now, I have rounding and caps. Rounding refers to my fillet, and all these are separate objects. Let me undo a few times to go back to my generated object. Now if I create a single object, then by pressing C, I'm actually creating one single geometry. What happened here was that the caps and the rounding were welded wherever the points met. Let me undo to go back to my generated object. If you are going to use your generated object under any generator, for example, the Subdivision Surface, then it's advised that you use the Generate Single Object. Otherwise, it won't be able to create the rounding you want between the separate surfaces. So this is with Create Single Object off, this is with Create Single Object on. Last but not least, we have the Rounding UVW Keep Shape, which actually allows us to create a seamless transition of our UVs from the cap and the rounding. A very simple right-click, Show Help, will show you exactly what happens in each case. This is off and this is on. And I know it's a bit cheating when you do a tutorial to show the Help, but, "Hey, I just cheated." In the next video, we are going to take a look at constructing a loft object using all sorts of different types of splines. And we are going to demystify certain of the parameters of this very interesting generator.
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