Orca3d- are lines actually fair?

[Angélique]

@DCockey With the expression "input data" I refer to the data or actions that the user must provide for the program to do its work. Happy?
I wonder if my English is so bad that you do not understand anything I say. In addition to analyzing my expressions in depth, you could give the OP information, examples, based on your experience with Orca3D, with the NURBS, with the "boats", so that he can draw conclusions about what he is worried about.

Your English as used on these forums is good, it's your ironic and very often sarcastic attitude in a pretended polite way while evoking polemic debates that gives you trouble.

E.g. the addition ‘‘Happy?’’ when answering a question for clarification is just sarcastic.

I wonder if my English is so bad that you do not understand anything I say.

Suggesting someone else doesn't understand anything you say like above is also sarcastic.

Often you're just wrong, while pretending to be an expert on the topic, which you then take as being not understood.

 

[DCockey]

Perhaps there is some confusion about the intended use, purpose and workings of the Orca3D Hull Assistants.

The Hull Assistants are intended to create a new outer hull surface based on some basic dimensions and proportions which the user inputs. They are not intended to replicate an existing design or match an existing set of lines and offsets. Orca3D has four different Hull Assistants for (round bilge) sailboats, (V bottom) RIBs, (V bottom) planing power boat, and (V bottom) boats with developable surfaces. Each has it's own set of input dimensions and proportions which the user controls.

In my limited experience with Hull Assistants the results appear to exactly match the input data, though as always the results should be checked to make sure errors or discrepancies have not arisen. If a surface from a Hull Assistant is used as the input outer hull surface input to create construction math models / drawings then any discrepancies between the outer hull surface and the construction math models / drawings would have occurred during the creation of the construction math models / drawings.

Again, the Hull Assistants are not intended to match an existing surface or an existing set of lines and offsets.

 

[gonzo]

In Orca3d, when using hull assistant, by clicking "create hull", are the resulting lines truly fair enough to loft and build on?

Lofting is the act of drawing the lines full size and fairing them. A loftsman will correct the lines for fairness and beauty.

 

[Ad Hoc]

Lofting is the act of drawing the lines full size and fairing them. A loftsman will correct the lines for fairness and beauty.

And here in lies the misnomer about automatic hull creation and Lines Fairing programmes.

Everyone assumes because - the computer is doing it - the Lines must be fair and correct. It is no different to the "old days" when the Lines were drawn by the naval architect and then given to the DO and the Mould Loft. The mould loft would take the Lines done by the naval arch - which were a generalised rough guide - and then faired by the mould loft.

It is assumed by many using computer software programmes that "this fairing" which was done by the mould loft, is done automatically within the programme. It is not. The user must still check the Lines to establish if they are fair - just as the mould loft did before, when taking the Lines from the naval arch. The Maths will produce a nice 'smooth' set of Lines such as:

But it does not mean it ia a production faired 3D hull shape suitable for plate development.

The user must still do exactly what was done before, check to ensure the Lines are fair. It is not called a Mould Loft anymore - because they no longer exist.
But it does not mean this function is not done (as it must be) or done automatically by the computer programme. This is where, just as in the mould loft, experience is required.

 

[TANSL]

Lofting is the act of drawing the lines full size and fairing them

Many years ago, more than 40 years ago, this work was not carried out on a natural scale. The 1/10 scale drawing replaced, advantageously, the 1/1 scale drawing. That does not mean that, perhaps, for very small boats, it can not be done from time to time but on big boats, it is not done that way. Nowadays the normal thing is to work with a computer but I do not know if that can be called "full size" lines. But you always have to check what the computer gives us.

 

[Ad Hoc]

Many years ago, more than 40 years ago, this work was not carried out on a natural scale. ..

And that relates to Gonzo's statement - how?

The 1/10 scale drawing replaced, advantageously, the 1/1 scale drawing. That does not mean that, perhaps, for very small boats, it can not be done from time to time but on big boats, it is not done that way.

Define big boats.

Nowadays the normal thing is to work with a computer but I do not know if that can be called "full size" lines.

If you draw at a scale, it is not full size. If you draw 1:1, it is full size. It is elementary.

But you always have to check what the computer gives us.

That is what he is saying.

 

[TANSL]

Interesting and captious questions, Ad Hoc

And that relates to Gonzo's statement - how?

In no way.

Define big boats.

According to, for example, the ISO standards in this regard, small boats are those of length L<24 m. (L as defined by ISO 8666)

If you draw at a scale, it is not full size. If you draw 1:1, it is full size. It is elementary.

That is debatable, not elementary.

That is what he is saying.

Whoever is "he", if he says that it is necessary to check the results of the computer, I am of agreement with him.

 

[Ad Hoc]

In no way.

So why highlight it then...????

According to, for example, the ISO standards in this regard, small boats are those of length L<24 m. (L as defined by ISO 8666)

So YOU are not able to define what YOU consider a big boat, you need to refer to a standard for design??

That is debatable, not elementary.

Again, pointless semantic polemic meaning what?

Whoever is "he", if he says that it is necessary to check the results of the computer, I am of agreement with him.

Drivel...

 

[TANSL]

So why highlight it then...????

Why not?

So YOU are not able to define what YOU consider a big boat, you need to refer to a standard for design??

Apart from what I may or may not define, the definition made by the ISO standard is the one that, when working with small boats, should be adopted in certain circumstances. It is much more authoritative than my definition or what you can do.

Again, pointless semantic polemic meaning what?

Meaning that what you have said does not have to be the absolute truth and that what you say, like what I say, is debatable.

Drivel...

The supreme technician arrived and, and as he did not know what to argue, said ... "drivels", and everyone adored him.

 

[Ad Hoc]

There is no point dignifying any of your utter nonsense with a reply.....just drivel.

It is just a waste of bandwidth...and distracts from the OPs question at hand.

 

[TANSL]

Little can your answers dignify anything. Have you really thought that answering me was going to dignify anything?. How pretentious!. But, as I know that you are a great prankster, I have to grab you for these moments of humor that make our lives happy. Not everything has to be technical, serious and boring answers. Thank you for another one of your magisterial lessons, professor. You're my idol.

 

[Angélique]

Little can your answers dignify anything. Have you really thought that answering me was going to dignify anything?. How pretentious!. But, as I know that you are a great prankster, I have to grab you for these moments of humor that make our lives happy. Not everything has to be technical, serious and boring answers. Thank you for another one of your magisterial lessons, professor. You're my idol.

You know TANSL, the funny thing is Frederick Trevor Hill found in Abe's statements a quote that looks to be made for the kind of wordings you use on these forums, as well as for the usual value of your postings: ‘‘He can compress the most words into the smallest ideas of any man I ever met’’, as published in Lincoln the Lawyer (1906), but till now no one was able to find out who Abe was talking about there, since ‘‘history has considerately sheltered the identity of the victim’’ it says . . .

But among many other things Abe is very famous for his foresight, so I'll think by now we know who he talked about there . .

Here's a free download of the book, see page 218 - 219, it's also available as PDF, (Book page 218 = PDF page 248).

Now back to ‘‘Orca 3d - are lines actually fair ?’’ I'll guess . . ​

 

[Angélique]

Why not ?

Because it was in no way related to the post you quoted, unless of course if your second line statement in post #22 about this matter was untrue . .

 

[Alexanov]

In Orca3d, when using hull assistant, by clicking "create hull", are the resulting lines truly fair enough to loft and build on?

Hi,

If you not sure about your hull lines quality you can check it here - Shape Checker http://msi.as/ShapeChecker.aspx and this is for free.

 

[Angélique]

Here's how Dudley Dix once did it, but I'll guess he drew up the Cape Cutter 19 far over a decade ago, the bottom quote comes from the Cape May 25 . . .

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‘‘ I took the unusual step with this one of drawing the lines on paper then moving them across into the computer lines fairing program for final fairing. I did this because it is easier to assess the aesthetics and proportions of a chine or lapstrake hull on paper than on a computer screen. I felt that I would produce a prettier hull this way.

The next step was to move it across into a 3D modelling program, which allowed us to generate accurate full size patterns of all of the skin panels. ’’

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‘‘ It is lapstrake plywood in construction, with carefully proportioned curves and strake widths to produce a pretty hull. In lapstrake hulls the chines are accentuated by the step in the joint, so an unfair line looks very ugly.

When I was designing the Cape Cutter 19 I found that I could easily fair the chines in my CAD programs but had problems visualizing the proportions of the panels relative to the overall profile and each other. I did not feel confident of producing a hull that would look good from all angles, so I returned to the old steam powered drawing board to draw the basic lines. After that I went back into the CAD programs for minor tweaking of fairness and to produce 3D rendered images so that I could look at her from all angles. The result was a boat that is attractive from wherever she is seen. The bigger sisters have benefitted from that process by being directly scaled up from that original set of lines. ’’

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