Offset Table import

DELFTship forum Hull modeling Offset Table import

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    • #44890
      MBerlin
      Participant

      Hi,

      I try to import an offsetable.txt into Delftship.

      I always get an error message:

      Critical program error

      unit name: sysunits

      error message: invalide input

      error class: elnouterror

       

      txt. Data is attached maybe some finds a mistake or can tell me what’s wrong.

      thx for the Help!

       

      Attachments:
    • #44893
      Marven
      Keymaster

      It seems that you made a type in one of the numbers. Replace the decimal separator with a period and then it should work.

      image_2023-11-28_071158202

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    • #44899
      MBerlin
      Participant

      Hi,

      great, it works.

      Thanks for the help!

    • #44901
      MBerlin
      Participant

      Hi,

      i got it working, i have the model running.

      It showed some problems, which  i got fixed.

      I’m struggling to get the Deckline right, the fwd Sheer is correct. In the back, the deckline drops lower.

      How could i fix this? I want to get rid of the Points on the centerline ( purple) , don’t want to lose the Points in the front, same height, (Yellow).

      Under the Keel, points are missing correctly. (Orange)

      Thanks for your help!

       

      Attachments:
    • #44903
      Terrance Egolf
      Participant

      Hi MBerlin,

      I am no expert on the importing of offset tables in this program, but I have used them before with mixed success.

      First, the “0.000” entries under the column 0.132 (m?) waterline must be nonzero in order to make sense. These entries represent the lateral (y-) coordinate at each waterline/station combination at the surface of the hull. Entering 0.000 in these fields tells the program that the hull beam is zero (at the centerline) at these locations. I think you should try leaving these fields blank to omit waterline date where there is no hull surface at these stations along that particular waterline. This will probably require, after importing the table, manually inserting some control points in the outboard sheer line (rail) to help smoothly terminate the 0.132 waterline net edges at these locations.

      To define the deck, I think you want to use the third and second columns from the right-hand side of the table. These columns are discussed on page 33 of the v. 15 Manual. I’m afraid that the function of these columns is not described very well in the manual. For example, the “left column” establishes the deckline height, but it doesn’t define whether that is the outboard height or the centerline height. I suspect it is the former, but without testing the coordinates myself, I can’t be sure. The “right column” is a bit more clear, and evidently provides the outboard lateral dimension (y-coordinate) of the deck edge at each¬† station. So taken together, you might assume that the “left column” probably provides the outboard deck height (z-coordinate) at the hull surface.

      [To DELFTship] It would be very helpful if all the terms used in this Table of Offsets discussion were formally defined in layman’s terms and illustrated on a model hull. For example, what does “contour” mean in the context of this table?

      Going further, if the above discussion defines the outboard edge of the deck surface, it would be helpful to program users if the Manual would describe somewhere how add a cambered deck surface so that it accurately intersects this line just defined! I have done this myself using a deck camber template, but it is very tedious.

      Hope this answers your questions, MBerlin.

      Terry

    • #44907
      MBerlin
      Participant

      Hi Terrance,

      thanks for your answer!

      I tried leaving the fields blank, I got a critical program error. So it is necessary to fill every field.

      I got the columes, which define the deckline, correct. It works fine.

      Also, the Keelconture works fine. In the Bow section, you can see that the point, with field indication 0,000, in front of the Keel are not shown in the model.

      So the question is, why is it under the keelconture working but above the deckline isn’t?

      cheers for any help!

       

       

    • #44908
      Terrance Egolf
      Participant

      Hi MBerlin.

      If you could attach your text file to a post here, I might be able to check out what it is doing. I don’t want to try and transcribe what you have shown in previous posts, which would likely introduce errors.

      Terry

    • #44912
      MBerlin
      Participant

      Hi Terry,

      here is the File.

      Sorry, could I have done that earlier.

      Thanks for your help. Right now, I do a master craftsman program in boat building.

      I want to get better in digital drawing, so I can do technical drawing Exam with Delftship and other CAD.

      MBerlin

       

       

      Attachments:
    • #44914
      Terrance Egolf
      Participant

      MBerlin,

      Do you have a photo, diagram, or plan of the vessel you are trying to document as an offsets table?

      It would help tremendously if I could visualize what you want to end up with. Also, I assume the coordinate system is in metric units, correct?

      Thanks.

      Terry

    • #44916
      MBerlin
      Participant

      Hi Terry,

      metric is correct.

      I attached four Files:

      1. Model created via Coordinates

      2. txt. file the coordinates table

      3. Model created with Offset table

      4. txt. file the Offset table

      The Offsettable- Model should look like as the Coordinate – Model.

      If you open the Offsettable- Model you will see right a way the problem.

      In the Offsettable column, 0.132 is causing the trouble. The Waterline Jumps to the centerline between station 0.000 and 0.800.

      Ideally, the points would not appear in the Model. Like the Points in front of the keel. (column 0.007, between station 0.700 and 0.988)

       

      Thanks, Terry!

      Attachments:
    • #44921
      Terrance Egolf
      Participant

      Hi MBerlin,

      Thank you for these files. Sadly, my computer is in the shop for at least a week due to a potential malware intrusion from an email correspondent, so I won’t be able to check these out for an indefinite time.

      Will get back to you eventually.

      Terry

    • #44942
      Terrance Egolf
      Participant

      Hello MBerlin.

      I apologize for not responding sooner. The past several weeks have been quite busy for our family.

      I have worked over both the text file and the model itself to see if there is a solution to your problems. I have to confess that I can’t sort it out. The import (and export) Offset feature has issues that defy explanation.

      First, I imported your original Offset-table-2.txt file and this is how it displays:

      Original-Model
      Notice the inward fold where the upper waterline data is zero.

      Then I attempted to clean up the file to approximate what I think you were looking for:

      Cleaned-Up-Model

      I eliminated the fold and smoothed up all the stations and waterlines.

      Then I exported an offset table based on the cleaned up model from the program. But when I imported THAT txt file, I got this result., which is worse than the original.

      Exported-Offset-Table-Model
      This model derived from the program’s exported offset table is full of errors, and again includes the fold where the upper waterline data is zero.

      So, I’m afraid I can’t help you. I’ve attached the revised model file for you to take a look at. I would consider relying on an offset table in this program to be a last resort.

      Terry

      Onemeter-Offset-Revised

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