Freeship to Michlet questions

Discussion in 'Software' started by Deering, Dec 9, 2005.

  1. Deering
    Joined: Feb 2005
    Posts: 481
    Likes: 25, Points: 18, Legacy Rep: 44
    Location: Juneau, Alaska

    Deering Senior Member

    I've developed a hull in Freeship that I'm trying to export to Michlet to perform drag analysis. I get some of the basic hull info showing up in Michlet (length, beam, etc) but no hull lines. I'm a little confused about the necessary file structures.

    Here's what I think I know:

    1. Freeship has a Michlet export mode. As I understand it, the exported file becomes the 'in.mlt' file after renaming.

    2. Michlet needs at least two files to analyse the hull - the 'in.mlt' and the 'useroff1.csv'.

    3. The 'useroff1' file is of hull offsets. It needs to be in comma-delimited format.

    4. Freeship can export an offset file, in text format.

    Here's where I'm getting confused:

    1. Freeship manual says that the offset export is only for the port side of the hull. Is that adequate for michlet? Or is it looking for a complete hull offset? If so, what would that look like?

    2. I'm confused by 'stations' and 'waterlines' as defined by the Michlet offset file structure. Can someone explain what Michlet is looking for there? The Michlet manual says that the number of stations and waterlines must match what was stated in the in.mlt file (I think), but the offset file that Freeship produces appears to have varying numbers of stations per waterline. How do I correct that, or do I need to?

    3. The file that Freeship produces is not comma delimited. Do the values just need to be manually edited?

    4. The whole offset file export/import routine looks like it has high potential for being very tedious and mistake-prone. If I'm grasping this right, I'll have to edit each file all over again for each hull modification I make in Freeship. Michelet mentions some other hull info that it can accept (mathematical series and spline formats). I don't understand what those are, but is it possible to extract those from Freeship somehow, perhaps going through an intermediate step?

    Any insight you Michlet gurus can offer would be MOST appreciated!
     
  2. Martijn_vE
    Joined: Apr 2005
    Posts: 254
    Likes: 24, Points: 0, Legacy Rep: 401
    Location: Netherlands

    Martijn_vE Marine software developer

    Michlet export

    First of all, FREE!ship exports only 1 file, with the extension .mlt. The offsets are embedded in the file. You can decide yourself what the filename will be, but in.mlt seems the most obvious. Secondly, the offsets are created at the intersections of stations and waterlines. So you'll have to enter a number of stations and waterlines and then FREE!ship will create the offsets and show them on screen. Only one half of the hull is calculated (portside) but it is mirrored on screen and when you export it to Michlet. The principle "what you see is what you get" (WYSIWYG) is appropriate here. The file contains what you see on your screen. If you don't see anything, you're either doing something wrong, there is a bug in the program, or you have created the hull on the wron side of the centerplane (all negative coordinates). If you still don't succeed in exporting the offsets, send your FREE!ship file to info@freeship.org and I'll have a look.
     
  3. Deering
    Joined: Feb 2005
    Posts: 481
    Likes: 25, Points: 18, Legacy Rep: 44
    Location: Juneau, Alaska

    Deering Senior Member

    YES! I was exporting the SB side of the hull, not the port side. Duh. Once I mirrored the hull everything works perfectly. A much easier process than I feared.

    Thank you!
     
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