Join Veejay Gahir for an in-depth discussion in this video Curve primitives: Circles and sweeps, part of Alias Essential Training.
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- In this video, let's take a look at creating some basic curve entities. Because we're creating a curve, it's gonna be under the Curve Creation Tab. So if I open this up, right-click on there, I'm gonna go to the very top under Primitives, and we're gonna open up the options for Create Circle. Now, you'll notice it's a very simple dialog box right now. It's gonna create a periodic circle, degree 5, spans 12. And let's just do a reset. And I'm gonna go "Go with that". You don't have to use reset every time. I just wanna show you that if you do alter any of these values, for example, if you do a reset, that will take you back to the default installation options which are generally the ones to use.
So let's say "Go with that", and I'm gonna zoom into this area here, and let's just simply place the circle right in the center like this. Now, you'll notice as soon as I put the cursor down into the location where I want the center of the circle to be, I get this gizmo comes up. And this gizmo allows me to move the circle into any location I want. If I click one of these squares, either the green or the red, the center turns to a square as well and this allows me to proportional scale. And if I pick on one of these, either the red or the green square, it allows me to non-proportional scale, like so.
I can also rotate. And, using these arrows, I can also move like this. So if I pick on the Translation Function, I can go to the center and do a free pan. Pick on one of those squares, I can go to Proportional Scale, or I can go to Non-proportional Scale. Let's just delete this. Let's do it again. Now you'll notice as soon as I've executed the command using my right mouse button and selecting a circle, the circle icon now is highlighted in red. So I can just go ahead, click that again, and just place the circle where I want to.
So I wanna go ahead and just scale this down roughly to the size that I'm looking for which is one of these buttons. Now at this point, I'm gonna select nothing. If you feel that the curve is not clear enough for you, there's a couple of options we can do. We can go to Object Display > Draw Style, and under Curve, let's just change the Line Width to Double, like that. The other thing we can do, is we can move our image plane down a fraction because if we go into this view here, you'll notice that the circle and the image plane are lined right on top of each other.
So simply go ahead, pick object, and we're gonna move this plane down using my right mouse button just a fraction. It doesn't have to be an exact amount, like that. Let's go back into the top view. And at this point, I'm gonna go ahead under the Layer Image, and I'm gonna set my state to Reference. Now, this way, I can't pick it and move it accidentally. Because if I'm in the modeling process and I'm placing these circles to represent these buttons, I don't want to by accident move that image plane, 'cause that could cause huge problems downstream.
So, I've come out of the command. So now if I go back to select my circle, if I want to scale, non-proportional scale or move, now I have to use my Transform Functions. So let's open up Transform. And you can see I can go to Move. I can also go to Scale. And I can also go to Non-proportional Scale, like so, using my left mouse button for horizontal, and my right mouse button for vertical. Let's undo that. Let's undo again. Now, you'll notice that when I did place this circle, there was no option to specify an exact radius.
So let's do it again. At the top, there's no option. And even during the actual opening of this dialog box, we didn't see an option for creating an explicit value for radius. It's just not available in this particular command. Now, if we do a Control + 5, this opens up an information window. Now, this is a very valuable dialog box. And it gives you basically information about the entity that you've selected. So it's about the internal DNA of this square. What the position is, what's the scale. And if we open all of these options up, you can see that we have information regarding this particular circle.
So starting at the very top, we have the circle, we have the name, we can change the name here. Tells you what layer it's on, tells you the layer name, and also the translate values for x, y, and zed. Also the rotational and scale. Some of these values you can't change. For example, I can't do anything with the pivot information, I can't do anything with the bounding box information, it's all locked out. And it's also telling me that it is a periodic entity. But what I can do here, is I can change these values. So let's say we go to Translate, let's make that 0.
Let's make that 0 and the zed is 0. So what that should have done, it's moved that circle back to the global 0, 0, 0 or origin of model space. So now if I go to the Move Command, you'll notice now that the translate values are changing as I'm moving that particular circle. Also if I non-proportional scale, I'm gonna use my Marking Menu now. Control + Shift + Middle Mouse Button, non-proportional scale, and I wanna use my middle mouse button again.
You'll notice that the non-proportional scale value now has changed. So I could go back and make that a true circle again. So this is a very valuable piece of information that we can retrieve from any piece of data that we have here. And incidentally, you don't have to just have one picked at a time, we can actually go ahead and pick this object as well. So now we have information for one of those circles, and we have information for the other circle as well, and you can stack all this information on top of each other. Select nothing, and the information window is blank now.
Let's go ahead and let's just delete this. I'm gonna pick this circle, and I'm going to just switch off the image plane for a second here. Let's have a quick look at what a periodic entity is. Now, this one here is a circle that's created as a periodic entity. And if I select nothing, let's go back to our options and let's just switch off periodic circle, and let's say "Go". And I'm going to scale this value to approximately the same size of circle. Now you can see that they're very different.
The internal DNA of this one and this one here are completely different. One is periodic, and one is non-periodic. And if I do a Control + 5 this time, you'll see that circle is periodic and the second circle that I created is just open. So what does that mean? So, I'm gonna go to Pick CV, and I'm gonna pick one of these CVs here, and I wanna say "Move". So let's just move it out into space. And I can just go ahead now and pick any one of these CVs without any keyboard interaction and move them.
So essentially what this is, this circle endpoint, the start and endpoint of that circle have been glued together permanently. So I can't break that circle at all. So let's press I to make that invisible and let's go to this one now. Pick CV, I'm gonna pick one of these CVs now. Here's the first clue: even though that's the start and end of the circle, Alias is now asking "Well, which endpoint "do you wanna select? "Do you wanna select this one or this one?" Well it really doesn't matter right now. And if we say "Move", you'll notice that I can break that circle and create a gap between there.
So that's a non-periodic entity. So let's go ahead and delete that and let's bring back our image plane. Let's go back to Circle, click on Periodic and go place that in the center and then just scale this down, like so. Now in this particular case, we wanna keep the same button size for all of these. So once we've got the size that we like, we can just simply Control + C, Control + V, copy, paste, and then we can move. Control + V to paste again and move. So standard Windows operations.
Control + V one more time and move. Now we can pick all of those entities at the same time. And we can go to Scale. I'm using my Marking Menu, Control + Shift + Middle Mouse Button. And I can scale these proportionally and because the pivot point is located in the center, all of them will scale towards the pivot point, like so. Now, we can also take one of these circles, and we can move it to this interior portion of the handle, and we can scale, and we can non-proportional scale, like so, and we can also rotate as well.
Make sure that we're rotating it in the right axis, in this case, it has to be the right mouse button because we're rotating in the missing axis in this case which is the zed. And then we can move and we can continue non-proportional scaling it, and again we can go to Move. So we can actually start to capture some of this profile with just very straightforward geometric entities like a circle. So let's delete this. The next entity I'm gonna show you here under Curves is the Sweep. So let's go to our options, and you'll notice we have a library of sweeps that we can use.
So let's just go ahead and pick one of these. Let's pick this one here for example, and then simply select a location in model space. I wanna close this down now and I'm gonna go to the star right in the middle here of this gizmo and I'm gonna move the sweep like so. Again, we can scale, we can rotate, and we can again move, until we try to capture a portion of the handle that we're trying to achieve, and again, you can also non-proportional scale this.
So let's say we're happy with this portion here. We're trying to capture this mid portion. I'm just gonna do this very quickly. Once you have a portion that you're happy with, we need to break this because obviously this is just one complete entity. So what we're gonna do now is we're gonna detach this entity. In other words, we're gonna break it into pieces. So the command for that is Object Edit > Attach > Detach. And we're gonna be looking at this in more detail later, but very simply, just pick on the entity, no keyboard interaction, select the location you want to break, spacebar to accept, and on this side too, spacebar to accept, pick object.
And now you can see we can delete this portion here. So we have this remaining part of that initial sweep. So that's just some basic entities and curves. Now, circle you'll be using a lot of. It's a great command and it's a great start to any surfacing project to be able to understand how circles can be manipulated and shaped accordingly.
- Manipulating views and entities
- Working with layers
- Creating curves
- Sweeping, extruding, revolving, offsetting, and blending surfaces
- Modifying geometry
- Moving, scaling, flipping, and rotating objects
- Trimming curves and surfaces
- Creating copies of objects
- Aligning, combining, and splitting objects
- Analyzing geometry
- Shading models