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#41 Ms. priyanka Gusain

Ms. priyanka Gusain

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Posted 11 March 2019 - 01:56 PM

hi all !

 

I have hereby attached an IGES file. can you pls tell me how can i create variants of this hull keeping displacement more or less same.

 

 

thnx!

 

 

cheers

priyanka


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#42 Mr. Heinrich von Zadow

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Posted 12 March 2019 - 09:52 AM

Dear Priyanka,

 

I can not see any attachments, but since this thread is more about fully parametric modelling while you are interested in a partial parametric approach - why don't you just open another thread to keep things a bit more organized. Feel free to sent me a PM when you have done so and I will take a closer look.

 

@Chris:

 

1. It is not about the image curves - they are just used to allow trimming.

2. Try increasing the number of sections of the main meta surface. Keep in mind, that you will have to ensure a horizontal tangent at the end of this chine curve other wise you will loose continuity towards the bow region.

3. You will most likely need something like the 'subsurface from surface curve' (in surfaces / sub surface / more / ...)

 

chineElevation.gif

 

Cheers,

Heinrich


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#43 Mr. chris baki

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Posted 12 March 2019 - 11:28 AM

Hello mr. Heinrich,

 

1) I asked about the image curves because when the ruled surface was created from the multisegmentsmoothcurves the result wasnot that good. On the contrary with the use of image curves 9and unit speed trck) the resulted surface is better, so i guess there is some difference...

2) Anyhow, I have still the same problem for which i asked help for the skeg connection. I mean when i use Brep i get the same problem concering the sections produced over the skeg region (coupling of hull and skeg is not correct, the section line describes both hull and skeg which is wrong... - See attached image problem1)

3) As far as it concerns the front region of main metasurface, i increased the number of interpolatedpointsinsurfacesirections from 15->75 but the result is the same (attached image problem2) and of course if i increase the corresponding number in frontmetasurface, the bow sections change/almost competely dearranged..

 

My main problem is the skeg region because i can get the right sections towards chineLow end if i just insert the a groupSurface as source at sections instead of Brep... Still, though i dont get why if i utilize Surfaces as input the sections are ok (at x 32m approx.) and if i use Brep the problem remains...

 

Thank you,

Cheers,

Chris

Attached Thumbnails

  • problem1.png
  • problem2.png

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#44 Mr. Heinrich von Zadow

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Posted 12 March 2019 - 02:43 PM

Dear Chris,

 

1. In that case, it is the parametrization of the curve that is important. For ruled surfaces it is always a good idea to have at least a somewhat similar parameter distribution on both rails.

2. That is because your Brep is not trimmed either.

3. It works for me - which CAESES version do you use?

 

I put the Brep together so you can understand better how this is supposed to work in CAESES and I also created a set of sections as I understand this is what you want to export.

 

BrepHull.png sections.png

 

P.S There are filters on the bottom of the 3D view to turn on/of the sections / offsets / surfaces etc... so you don't have to turn off the section visualization manually

 

Best regards,

Heinrich

 

 

Attached Files


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#45 Mr. chris baki

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Posted 12 March 2019 - 05:13 PM

Good Afternoon mr. Heinrich,

Thank you a lot for your quick response.

 

1) ... That's the role of unit speed? To make it easier for the ruled surface between 2 curves with different length?

 

2) I see, yes now it is ok. But how did u refer at the Hull Brep to cut and trim Skeg Brep? If i open at Hull Brep menu i see nowhere Skeg Brep as input....

 

   Sth else to mention: If i tried to implement the other way (the one mentioned at fastmonohull exemple) in order to cut n trim skeg the biggest problem i have is that the edges of the subsurface seem really different than the original ones. I increased the resolution properties to 500x500 but the same problem.. (see attached images prob3&4.png)

 

3) i use version 4.4.1. For me the problem remains...(see attached .probRemain.png).

 

Moreover, i want to ask for one more thing concerning my version. 50% of the times i try to open a second Caeses project i cannot. How can i resolve this? Because i would like sometimes to check 2 projects simultaneously and now i can say that possibility depends on chance... ?!?

 

Thank you very much,

Chris

Attached Thumbnails

  • probREMAINS.png
  • problem4.png
  • problem3.png

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#46 Mr. Heinrich von Zadow

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Posted 13 March 2019 - 07:52 AM

Hi Chris,

 

1. The 'role' of unit speed is nothing more than parameterizing the curve such that the internal parameter t[0,1] runs with equal 'speed' per curve length. Since ruled surfaces create straight rulings between equi-parametric curve positions the parameterization allows you to massively influence the shape of the resulting suface - see example of two circles and the ruled surface in between for different parameterizations.

parameterizatinUnitSpeed.png parameterizationClustered.png

 

2. Check the object editor of the Brep. The 3 steps I used are:

 

1. add sources (bare hull)

addingHull.png

2. project and trim (skeg contour)

trimmingSkeg.png

3. boolean sum (skeg)

addingSkeg.png

 

3. In the file you attached, the 'number of interpolated points in surface direction' for the meta surface main was set back to 15. I checked with 4.4.1 and it works for me.

 

 

Cheers,

Heinrich


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#47 Mr. chris baki

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Posted 13 March 2019 - 12:31 PM

Hello mr.Heinrich,

 

Thank you for your detailed explanations.

 

You are right, i had it set back at 15 because nomatter what i tried yesterday did not wok out, cant tell why..

 

Anyhow, i tried again now and the result is fine. If i set the number of interpolted points in surface direction of MainSurface above 35 and leave that of FrontSurface at 15 everything seems to run smoothly.

 

Thank you very much for your up-to-now assistance,

Chris


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#48 Mr. Heinrich von Zadow

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Posted 13 March 2019 - 12:49 PM

Dear Chris,

 

that is good to hear, glad I could help!

I think it would be very nice if you could come up with a 'clean' final version of the project so that other user searching the Forum can profit as well.

 

Cheers,

Heinrich


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#49 Mr. chris baki

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Posted 13 March 2019 - 07:45 PM

Yes sure, i had it in mind too.

I ll need some more time though to finish it, clean it up and maybe some more queries :)

Thank you for your help,

Chris


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