# Generic Bow Defined by a Single MetaSurface

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The following example consist of a single meta surface that is used to define the bow of a large varieties of ship kinds.

The model permit large variations of the shape from a typical bulbous bow of large vessels to vertical bows as seen in sailing boats, for instance.

First a station is defined by points as the keel, bilge, waterline and deck, plus some auxiliary points used to control the tangent of each curve, as to say to guarantee a smooth transaction between each section of the station.

Then those points "runs" along the X-axis varying the coordinates, defining the station at each "X" position of the station. The points and curves of each station are the same, however transformed as defined by some "curve functions", in function of X-position. Thus, the same curve I used to define the bilge at the aft zone I also use to define the bulb at the fore end of the bow.

This simple model shows the geniality, by simplicity, of a parametric model defined via meta surfaces.

In this model the variables are:

-Beam

-Length

-Depth

-Draft

-Entrance Angle

-Stem Angle

-Bulb Beam

-Bulb Height

Finally, TPOs is used to see the station variation along the X-axis.

Regards,

HB.

Meta_Bow_4Forum.fdb

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hello

I have been studying all day this example

I know what it means but what does it stand for?

TPO stands for?

best regards

thanks for this tutorial

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Hello Mr. Repolho,

Thanks for your interest.

The model I posted is to exemplify  the usage of meta surface.

It gives you an idea in how to work with it.

It could be used as a hand to you to create your own model for instance.

TPO is just a parameter that can be varied by the user to visualize the transformation that is been done to the initial station that possibility the surface to be created. It is a "visualization tool" where you send the station To Position Of...

I hope it helps you to clear your doubts.

If you need any further support don't hesitate to contact me.

Regards,

HB

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Hello Mr. Repolho,

Thanks for your interest.

The model I posted is to exemplify  the usage of meta surface.

It gives you an idea in how to work with it.

It could be used as a hand to you to create your own model for instance.

TPO is just a parameter that can be varied by the user to visualize the transformation that is been done to the initial station that possibility the surface to be created. It is a "visualization tool" where you send the station To Position Of...

I hope it helps you to clear your doubts.

If you need any further support don't hesitate to contact me.

Regards,

HB

Hello, thanks for the answer

This is exacly what i will be doing. I am studying all your samples in order to understand how to generate a container vessel fully parametric.

This is one of the objective of my master thesis in naval architecture.

I will after create some features to calculate resistance and cargo volume capacity.

best regards

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Hello

Could you please give a hint on the comand getarea presente on the parametric model of the container ship tutorial?

On the parameter of the área apears the following, section.getArea(2, 0) * 2. Its the calculation of the mid ship área but what does the 2, and the 0 means.

I read its unsigned axis but i couldnt really understand.

best regards

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Hey Carlos,

The first number defines the FUnsigned axis which could be x-,y- or z-axis and

the second number defines the FUnsigned plane for example: 'X-Y,Z', 'Y-X,Z', 'Z-XY'.

FUnsigned stands for a positive non-floating number which is 0, 1, 2, 3, .....

section.getArea(2, 0) * 2

The '2' stands for the z-axis and the '0' for the "X-Y,Z" Plane and the resulting area is multiplied by two.

It is the area under the FCurve section in z-direction.

Does this solve your problem?

By the way all commands are listed in the documentation brower in the category global commands.

Regards

Karsten

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Hey Carlos,

The first number defines the FUnsigned axis which could be x-,y- or z-axis and

the second number defines the FUnsigned plane for example: 'X-Y,Z', 'Y-X,Z', 'Z-XY'.

FUnsigned stands for a positive non-floating number which is 0, 1, 2, 3, .....

section.getArea(2, 0) * 2

The '2' stands for the z-axis and the '0' for the "X-Y,Z" Plane and the resulting area is multiplied by two.

It is the area under the FCurve section in z-direction.

Does this solve your problem?

By the way all commands are listed in the documentation brower in the category global commands.

Regards

Karsten

Hi!

Thank you for your answer, i must admit it was a stupid question. After sometime i discovered it by my self.

Somehow i couldnt find the answer on the help resources so i decided to ask.

I am at the moment having some trouble to rewrite a new main frame following the containership tutorial, i will write here any following doubt.

Thank you once again

best regards

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Hello once again,

I added a keel plate to the bottom of the hull controled by a simple parameter called HalfKeelWidth.

My problem is simple, how do i limit the value of this by the yfob parameter in order then when i add values to the parameter outsider the code it respect the bottom curve YY value.

I will place a bit of the code and give an exemple below:

//the Keel

bsplinecurve Keel([[x,0,0],[x,halfKeelWidth«YFOB,0]],1) // i thought initially that maybe i would have to do a if cicle, but is it possible somehow to do like this,

// the bottom

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Hello again Mr. Repolho,

I'm not sure if I understood what you are trying to model. But, if you wanna to limit a parameters you could either use an "if" statement, please check our "insert snippet" feature to guide you through it, or you can set a relation between your parameter and your design variablel, for example:

Maximum value is "YY"

Minimum value is "zero"

then the design variable "D" that you use to control this dimension can be varied from 0 (zero) to 1 (one), and the value of the parameter used for the modeling is itself is defined by D*YY

Best regards,

Helio.

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Hello,

Thanks for the answer. I will try that condition.

Anyway i just wanted to control the Flat of bottom curve restriction so that when i insert the keel plate i can have the upper boundry of the yy coord, limited by the yfob in the various sections of  the ship hull.

Maybe i should send the model to you? what do you think?

regards

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Hey Carlos,

If you want to send us or directly to Helio and you don't want to share you project in the forum

you can send it via email to him. You can find his mail address in his signatur.

If you send him the model it is always helpfull to create a small pdf file with the specific task and

a discription of your problem.

Regards

Karsten

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Hello! Sorry for the delay answering, had some hardware issues.

Thank you for your answer. But i already figured it out.

best regards

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Hello,

I'm trying to open the Meta_Bow_4Forum in CAESES, but it does not show anything. How can I open it?

Best regards,

Carlos

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