Join Veejay Gahir for an in-depth discussion in this video Increasing the complexity of curves, part of Alias Essential Training.
- In this video we're going to take a look at how to increase the complexity of a curve to try to capture a shape and how to do it in a very controlled manner. In this view here we have a 2D canvas image plane. And an image plane is essentially an image that we're going to use for reference. And we can go ahead and we can change this to a reference like that. But we can also go up to Windows, Editor, Canvas Layer Editor. And this opens up another download box. And what I want to do here is I'm going to go and I can switch off the image plane, or the canvas image plane.
And with this slider I can change the opacity down to something like this. And that's going to work for this particular exercise. So the idea here in the left view is that we're going to try to capture the top portion of this hood with a curve. So let's go ahead, let's put one point here and one point here. And then very simply we're going to go to our transform CV function space bar, pick CVs X, Y, Z, and very simply we're just going to move this curve like that. And again, if you can't see the curve very clearly, let's go up to ObjectDisplay, DrawStyle.
We're going to go to Curves and make that Double. So again, all I'm doing now is trying to capture the outside shape. But you can see very clearly that we can't really do this with a single Bezier Degree 3 curve. So the next step would be to increase the complexity of that up to 4, spacebar to accept, and let's carry on manipulating these control points. And all I'm doing now is trying not to get to a situation where I'm bunching these all up in a corner like that. That's really not a good solution.
So I'm trying to keep a reasonably even distribution. There will be some bunching in this front nose because that's where the change of curvature is happening the most. So we get to a point like this. And again, I can't do anything with a 4. I want to go up to a 5. We're getting closer. So now I can start to see that I'm getting to a point where this is not too bad, but I'm missing this top corner, so I can go up to a 6. Now, the things is when we get up to a value of 6, we're really going beyond where we should be as far as increasing the complexity of the curve.
This will work, but it's not good practice to increase the complexity too much like this. There is a better technique for doing this. So let's go ahead. We'll select this. And in a situation where you've gone beyond where you need to be, very simply just go back to 1, spacebar accept. And let's go back to 2, spacebar accept, and we can go straight back into the modeling process. Let's select our Transform CV, and we're going to move this back like that. Let's go up to 3, accept.
And let's go back into Transform CVs. Now, at this point here I'm going to go up to a 4, but I don't really want to go beyond that. So let's go to a 4, accept. And let's just move these CVs again. Now, at this point here I know that if I go beyond 4, I'm going to start bunching these CVs considerably at this point. So at this point here I'm going to increase the Spans to 2 Spans and accept that. By the way, you could increase the Span and leave it at Degree 3. It's purely a matter of preference and which one gives you the right result.
But in this case here we're going to use Degree 4, 2 Spans. Now, you can see what Alias does. Alias actually creates an extra Span for us, and it puts it right at U value point 5. So we can go ahead now and move these CVs again. So we've got a little bit more control now. I can drag this. And where that Edit Point is you can see allows me to concentrate the change a little bit easier, like so. But again, this is not the ideal result. So let's increase that now to 3 Spans. I'm going to spacebar to accept.
And let's carry on in moving that point. But you'll notice now that the distribution of those Edit Points throughout point 3 at roughly at 1/3 of the way through. So in other words, Alias is deciding where to put those Edit Points for me. And that's not really the situation that I want right now. So there is another way to do this. And by the way, this is not too bad. This would probably work for a concept. But I still have to try to get closer to that front portion. So let's select this again. Very easily let's go back to 1.
And then let's go back to 1, accept. And let's up that to 2, accept, and go straight back into modeling again. So don't be worried if you go too far and it's a very complex or a dirty curve. We can just knock it down and start again very quickly. So again, we're going to go back up to 3, accept. And I'm going to model like this. This time I'm going to leave it at 3. I'm not going to go up to 4. And at this point here I'm going to come out of the command completely. And let's go to Object Edit, Insert command. And let's do a Reset, and let's say Go to that.
So there's our Insert command. And now I'm just going to pick on the curve. And where my cursor is located, that's exactly where my Edit Point's going to be located when I execute this command. And in green I can see a preview of how my control point distribution is going to be. So this is a very, very useful function to help me concentrate control points or edit points in an area of greater change, which is really going to be at the front of this hood. So I'm going to put one point here, spacebar to accept, and let's go straight back into the CV move.
And now I'm going to move this like so. And you can see when I released, that's exactly where I have my cursor. And that's where Alias has put that edit point. Let's go back into the Insert command. I'm going to pick a point right around here. And let's say spacebar to accept. Let's go back to the Transform tool. And now I'm going to just take this a little bit like that. And now we're getting a lot closer to the result that we're looking for. So this is something that's quite unique in Alias.
It allows me to insert an edit point at a specific location, rather than letting the system decide. In most CAD systems if I say take this curve and increase this to 5, accept, it puts them equally distributed. And then you have to go through the work of moving the edit points or moving those control points to try to capture a shape. And you could by accident increase the complexity way too far. This way I can have full control of where I'm going to place the complexity of this particular curve.
- 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