V5 Sweep (16 videos)

The “sweep” tool in Catia V5 can be daunting: it’s driven by a huge dialog box with literally dozens upon dozens of alternate configurations. Fortunately, it’s not actually as complicated as it looks, and it is quite possibly the most powerful parametric surfacing tool available in any CAD package.

Here I’ll be going through all of the various types of swept surfaces that can be created using Catia’s “Sweep” command in V5 R18. I’ll be trying to cover almost the entire tool in detail, so there are quite a few videos here. I recommend starting at the beginning, and watch each video in sequence.

Use them, love them! I had to make over a dozen videos to document the entire tool!

Enjoy!

1. File Setup, Creating Basic Curves (part1) (part 2)

   
   
   
   Because this is a learning resource, I don’t want to make any assumptions. I’ll start from the very beginning, and even show you some nice tips and tricks for creating simple thru-point splines. I’ll be showing a sketch-based method as well as three other non-sketch based methods that allow for easy manipulation. I’ll also look a bit at tree organization using geometrical sets and groups. It’s a high-level overview, but it’s a start! Click here to watch the video.

2. Explicit, single-rail sweeps. Intro to “spines”.

   
   The “explicit” type sweep in Catia is like the “monorail” sweep in other surfacing packages. It’s very simple and easy to understand if you’ve ever used a swept surface in any other CAD package. The one thing that might throw you is the use of a “Spine.” A “spine” curve is simply a curve that is used as a normal curve for the orientation of the cross-sections of the sweep. I’m going to show an example here, but for a full explanation of “spine” curves, we’ll have to wait for a future tutorial. Click here to watch the video!

3. Explicit, bi-rail sweeps.

   
   If you’ve ever used a “bi-rail” sweep in another surfacing package, this one is probably very similar. There are some tricks, however. It is a very flexible tool that allows for all kinds of naughty behavior; you’ve got to know what you’re in for! There are some great new features available in R18, giving you even more control of the surface (in the video you’ll see me learning as I go!). Click here to watch the video!

4. Linear Sweeps: Two Limits

   
   A “Linear Sweep” is exactly what it sounds like: it’s taking a linear profile and sweeping it along one or more guide curves. But there are lots of ways to define a line, and therefor lots of ways to define a linear sweep! The first one is the most obvious: A linear sweep between two curves. This surface can be extended to a length on either side, and one of the curves can also be used as a “middle” line, allowing you to create a sweep that is “symmetrical” across a complex curve! Fancy! Click here to watch the video!

5. Linear Sweeps: With Draft Direction

   
   Another way to define a line is to use a point, a direction, and an angle. That’s exactly what this surface is, except we’re doing it in 3D: we need a curve, a direction, and a “draft” angle. This surface type is primarily used as a means of creating a drafted tangency surface for the creation of other surfaces that require draft. There are lots of other ways to use it, however. I use it as a design tool quite often. Click here to watch the video!

6. Intro to “Laws” and “Reference Surfaces” (Part 1) (Part 2)

   
   
   
   Here we’ll be taking a look at the use of simple “Laws” to vary our draft angle across the surface, and we’ll be using the result to control the orientation of the profile curve on an explicit sweep. Laws are used constantly in parametric class-a surfacing. They are absolutely fundamental to creating clean, regular geometry. We won’t go into much detail here, but you’ll see a simple example of the use of a law with a linear sweep. There is quite a lot to talk about on this topic, and explaining this turned out to be more difficult than I thought; maybe a future tutorial will be in order.

7. Linear Sweep with Reference Surface

   
   This is often referred to as a “ribbon” in other surfacing packages. Basically we’re going to sweep a linear section along a curve at a set angular relationship to a parent surface. This could be a tangent relationship, but it could also be any other angle. This is an extremely useful tool for creating “creases” in surfaces. When combined with a “law” as an angle parameter, you can even make your crease fade in and out. I’ll be sure to show this in a future tutorial. Click here to watch the video!

8. Circular Sweep with Center and Radius (including Laws)

   
   This is often called a “tube” or a “pipe” in other applications. Quite simply, we’ll be taking a curve and creating a circular section around it with a given radius. We’ll also be able to vary said radius using a “law”. I’ve used complex laws like this to create adjustable parametric vacuum hoses! There are many, many applications for this surface type, far beyond what you might expect. Know this tool well; you’ll find you need it more often than you think! Click here to watch the video!

9. Linear Sweep with Tangency Surface

   
   Just as a line can be defined with two tangency conditions, a linear sweep can be defined with two tangency surfaces. Here we’ll use two of the circle-sweeps we made earlier to define our linear sweep. This is an extremely useful tool at times. Though I don’t demonstrate it in the video, a linear sweep like this can be used as an intermediate piece of construction geometry for the creation of an isoparmetric center curve that can be translated and used in the creation of a circle-sweep across the same span. Click here to watch the video!

10. Circular Sweep with Center and Two Angles

    
    This poorly-named tool basically allows us to create a “revolve” or a “lathe” operation, except that the axis for the revolve is not straight. So imagine you have a cross-section curve that you want to “revolve” or “lathe”, but you want to revolve it around a non-linear curve. Circle-sweep to the rescue! I’ve seldom had need of this tool, but on rare occasion it has come in very handy. I have never seen a tool like it in any other CAD package. Anyone know of another tool in which it exists? Click here to watch the video!

11. Circular Sweep with Two Guides and a Radius (including Laws)

    
    This is a very popular kind of circle-sweep, used to create very clean convex surfaces between two boundary curves. The reason for its popularity is because it is very reliable: it will always be convex. Other kinds of surfaces might have curvature descrepencies when radical changes to input geometry are implemented, but circle-sweeps are rock-solid. The disadvantage is that it can “break” if the radius value is smaller than the distance between the two curves. We’ll look at this issue, and propose some alternatives in the next videos. Click here to watch the video!

12. Circular Sweep with Two Guides and a Tangency Surface (includes ‘insert mode’ and ‘replace’ functions)

    
    This is another very common type of circular sweep, in which we’ll be using two guides and a tangency surface. We’ll also look briefly at the “insert” and “replace” functions, but for a full explanation of those, we’ll have to create another tutorial. Click here to watch the video!
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13. Circular Sweep with Three Guides (special methodology using a parametric bisector and normal translation)

    
    You might have wondered why I didn’t do this one first. Because the circlular sweep through three guides is so “obvious”, I thought I’d show you a real-world methodology that can be used to create a nice, clean convex surface that–unlike the “two guides and a radius” approach–will almost never break. Click here to watch the video!
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14. Conic Sweeps

    
    Conic sweeps in Catia might be the tool I use more than any other. They’re incredibly useful both as slab geometry for primary surfaces, and as blend geometry for secondary and even tertiary surfaces (if you know what you’re doing!). I’ll be going through this tool in more detail in future tutorials, but here’s the basic gist. Click here to watch the video!