More 'natural' curved connectors ?

[matthew.james]

All the connector line styles in Sparx are straight lines, apart from Bezier. Any tips on how to make the Bezier style lines more 'natural'?

I find that I can get a reasonably natural looking balanced curve for any given connector quite easily, but they don't survive well when diagram layout is changed. If you move one or both of the connected elements you often end up with a distorted, unbalanced curve that looks quite unattractive - can be manually fixed (but, manual). Often the connector ends seem to act like they're pinned (even thought they're not) and you end up with weird loopy lines coming out of the far side of the element and lines crossing over unnecessarily, almost like they want to twist around each other.

Note: I am using Archimate_Flow connectors, based on ControlFlow type, both of which have the same issues observed above. And no, I don't know whether curved lines are allowed / precluded / accepted or otherwise approved for use according to the Archimate standard.

Thanks

[Geert Bellekens]

I haven't seen any curved lines in the ArchiMate specification, although I didn't read anything that specifically forbids them either.

In general, I have hardly ever seen curved lines in any model, be it UML, BPMN, ArchiMate or something else, and I've never used them myself.

So even if they might be technically allowed, they don't seem to be "standard practice", so using those might look a bit odd.
Personally I use the orthogonal styles for almost everything.

Geert

[matthew.james]

Curved lines can be useful when you have multiple connectors coming in and out of the same elements, where orthogonal type lines tend to 'merge' together losing the distinction of the connections and where direct lines overlap each other (when perhaps it is not desirable to represent the relationship as a bi-directional connection).

Probably the most common example I have seen and used is the data flow diagram (which Sparx has an MDG for http://www.sparxsystems.com/enterprise_architect_user_guide/14.0/model_domains/data_flow_diagrams.html).  Not strictly an Archimate viewpoint, but can be represented using Archimate shapes and there aren't any official viewpoints anymore.

No, curved lines aren't necessary, even for a DFD, and I could use orthogonal lines instead - I was more curious as to what other peoples' experiences were.

[KP]

If you select a curved connector in EA, you will see that it has three points: the two end points and a control point. It's the control point that determines how much the line bends and in which direction. Unfortunately, the control point gets ignored during layout changes, which is why curves appear distorted. There's not much you can do in mitigation other than manually adjust the curves.

[Sunshine]

Not seen anything in the ArchiMate standards over the years to address the topic of curved lines. I've read pretty much all the literature out there on ArchiMate too. The ArchiMate examples in the standards past, usually show straight direct or orthogonal lines. However in Marc Lankhorst's book called "enterprise architect at work" one of the examples there are some curved lines, figure 1.1 Communicating about architecture.
Over the years I've occasionally informalised ArchiMate diagrams for the Management/Executive team and represented the elements with graphics and used beizer lines in Sparx EA. I call this Markitecture as its more aimed at marketing and selling the idea to management as the tend to go all cross-eyed if they see ArchiMate shapes.
So whilst not officially addressed I don't see why not use curved lines if its right for your situation.
You could post a question to Marc Lankhorst on the Linkedin ArchiMate group.

[matthew.james]

Unfortunately, the control point gets ignored during layout changes, which is why curves appear distorted.

That's pretty much what I figured. So - is this a feature, a design limitation, an oversight or a bug ... ?
Is it worth raising a bug or feature request for it?

[qwerty]

You might raise a FR. But I'd give it no big chance. Curved connectors and auto-layout are kind of diametral opposite things. The latter can be done on a very basic level by an automated system. But the curved lines are more an esthetic effect. Some smart AI in the (near?) future might handle that.

q.

[matthew.james]

Curved connectors and auto-layout are kind of diametral opposite things.

I'm not looking for auto-layout (at least in the sense of having the tool place the elements to get the clearest layout and connector routing).  I'm looking for "I move the element and the connector retains a balanced curve between the two".  Agreed that this is generally a "hard" problem to solve and different tools handle it in different ways.  I'm looking for something like the behaviour of the 'curved connector' in Visio where the curved line is re-routed in a sensible way as shapes are moved.

... and before anyone jumps in - I know Sparx is not Visio, I know I can use Visio if I want that behaviour.  I'm just putting it out there to see if:
- there is something I am missing or not doing right (seemingly not from KP's response)
- it is likely that this would, or even could, be improved (I'm guessing not)

[Sunshine]

Unfortunately, the control point gets ignored during layout changes, which is why curves appear distorted.

That's pretty much what I figured. So - is this a feature, a design limitation, an oversight or a bug ... ?
Is it worth raising a bug or feature request for it?

Call it what you like, a Feature, Design Limitation, Oversight or Bug no matter what it certain is an inconvenience to the user.

[Eve]

Call it what you like, a Feature, Design Limitation, Oversight or Bug no matter what it certain is an inconvenience to the user.

It's very inconvenient to me as a user that I don't have a button for 'do all my work for the day'.

While managing the control points of a bezier when one end is moved doesn't fit into that level of difficulty, I don't think that there is a single "right" behavior. It may be feasible to make a better automatic choice, but I would expect that in many circumstances a user will still want to tweak it.

[Glassboy]

It's very inconvenient to me as a user that I don't have a button for 'do all my work for the day'.

While managing the control points of a bezier when one end is moved doesn't fit into that level of difficulty, I don't think that there is a single "right" behavior. It may be feasible to make a better automatic choice, but I would expect that in many circumstances a user will still want to tweak it.

When you make the button, can it please pop up a paperclip avatar?

[matthew.james]

I think this is what I heard Simon say ... 
"At this stage changes to the behaviour of bezier curves is not a priority in our product roadmap"

It's very inconvenient to me as a user that I don't have a button for 'do all my work for the day'.

There's an app for that !

[Geert Bellekens]

I think this is what I heard Simon say ... 
"At this stage changes to the behaviour of bezier curves is not a priority in our product roadmap"

I can't say I don't agree.
Given the fact that bezier curves are hardly used by anyone, I think there are other, more pressing issues to tackle.

Geert