CGAL users discussion list

[Ronald Paloschi <>]

Hi Efi,

Thanks for answering!

I've made some experiments and this approach of approximating circles and arcs with bezier curves seems to be the way to go (and not difficult to be done ATM).

The book on arrangements is a great Resource!

Well, on to coding! Thanks for your help!

Ronald

---

From: <> on behalf of Efi Fogel <>
Sent: Saturday, October 10, 2015 12:51 PM
To:
Subject: Re: [cgal-discuss] Intersection of geometries

 

Hi Ronald,

There is no immediate way to handle all three types at the same time.

You need to define an appropriate instance of the Arrangement_2

CGAL 4.6.3 - 2D Arrangements: CGAL::Arrangement_2< Traits ...

Types: typedef Arrangement_2 < Traits_2, Dcel > Self a private type used as an abbreviation of the Arrangement_2 type hereafter. typedef unspecified_type

Read more...

<Geom_traits, Dcel=...> class template.

There is no immediate geometry traits that handle all 3 types at the same.

You can use the Arr_algebraic_segment_traits_2 geometry traits class. Essentially, this traits class handles all algebraic curves. However, defining the input curves you are interested in may not be intuitive. Secondly, while Arr_algebraic_segment_traits_2 was designed and implemented to achieve maximum efficiency, a traits class that is dedicated to handle bounded degree algebraic curves like those you are interested in could be more efficient. You are welcome to implement such a traits class on your own. In addition to the online help, you will find our book, entitled CGAL Arrangements and Their Applications, a good source of information. If you are considering purchasing a commercial license, directly consulting GeometryFactory can be useful.

BW, if, for example, you are willing to approximate circles with cubic Bézier curves, you can use the Arr_Bezier_curve_traits_2 geometry traits, but again, this may be not intuitive or even desired.

Best,

Efi

   ____  _        ____             _
  /_____/_) o    /__________  __  //
 (____ (   (    (    (_/ (_/-(-'_(/
                         _/

On Thu, Oct 8, 2015 at 3:25 PM, Ronald Paloschi <> wrote:

Hi,

In our company, we are experiencing around with CGAL, it is such an amazing library!

I need some advice that I think you fellows can give me.

First, context: We have a legacy CAD system with an in-house geometric library. We would like to start experiencing with cgal to replace this library.

Our model has 3 main types of geometries (Line segments, Arcs and Bezier curves).

It was really easy to move around and start using things.

Now I have a new challenge: Intersections. The Arrangements package seems the way to go, I'm still studying it.

My question: How can I setup an Arrangement that is able to manage those 3 types together (if possible)?

Thanks in advance!