Yet another Delftship offset problem

I am having difficulties with Delftship's offsets.

If I load file "ll_npl100a.txt" I get a hull where the transom is not closed. Why?

A further problem is when I try to export the hull as an offset file.
Should it give me the same file as the original?
Why is it chopping off the waterlines at the bottom and top, and the first and last stations? I've attached ll_npl100a_out.txt to show how the two files differ.

I would very much like to release some free software to calculate ship motions and some other useful hydrodynamics, but I can't decide on a hull design program that allows for the easy and accurate input and output of hull sections. Delftship would be ideal, but it doesn't seem capable of doing what I need automatically, i.e. without having to manually fiddle with offsets, creases etc.

Leo.

 

Leo,

I get "invalid unit identifier" error when I try to import it into freeship v2.6.

 

Thanks for trying, Ken, but it's a Delftship file, not Freeship.

Leo.

 

Leo
I believe it should produce the same file.

I note that if you <View> <Intersections> there is no station at 0.000 and no station at the stem. I checked that this was not a problem with the drawing space, which I believe is set by the length and beam.

As the first and last stations are not being shown they are not being exported. Hence if you repeatedly import and export the same vessel it keeps getting cut off by two stations on each cycle. I gather the same is happening with waterlines.

I think the question is for Martijn. I agree Delftship should be a good choice.

A more generalised format for the 3D shape may be iges format but the draft would need to be set in the software.

Rick W

 

I thought it was a text-based table of offsets which I presumed would be importable into both freeship and delftship. I guess I was wrong.