paper modeling a hull, newbie

[jon]

Hi all,

I’m new to this forum and to this software, but as it works with line plans, I am very interested in using it. I’m a paper modeler usually, and I’ve dabled in 3d cad, but the complex curves of hulls have always been a bit difficult for me to master and this tool set seems to help alot.

for my first project, I’m taking the freebee container ship that is downloadable, and working with that.

the problem with 3d models for paper modeling, is that they have way too many polygons to be able to fold and cut to make the model. I need a descent representation of the model with only a few hundred polygons, and at that, polygons that transition from one to the other with minimal degree changes. Also, I need true polygons: as in not exactly 3 sided triangles (3ds, obj “claim” polygons, but what they really mean is triangle,) In my world a polygon can have a hundred sides, and is still just one polygon (and not dozens of triangles.)

Now I built a cruise ship once from the deck plan, from your software I now know that the “deck plan” in engineering is called the “waterline plan” (as compared to the sheer/station plan, or the buttock plan) I found that with the waterline plan and the side view, I have enough to make a 3d model that translates to paper decently.

Anyway, after a few days feeling around with your software, I was able to manipulate enough to use the “line plan” to make some nice line plan drawings of the ship. I made jpgs of the line plans at 6667×2400 pixels, nice and big so I could make my decks nice an clean.

The 3d software I use is called AC3D and I use if because its native polygonn storage is multi polygon and not triangles.

To unfold the model I use pepakura, and as you can see it unfolded each deck rather nicely from a ability to assemble standpoint.

In AC3D I made 2 planes of the line plans for reference and tracing purposes. on the waterline view, I then traced the lowest plane and then extruded it to the height of the next deck. I would then drag the points of the higher deck to the waterline points of the higher deck. The height of the deck is then directed by the side view (buttock plan view???) to get it to align right. Once I’m happy with the deck, I take the new higher deck copy,paste, and extrude, with the new top ready to have its points moved to the next higher waterline plane. here are some pics;

Everything you see in these pics was done in about 4 hours.

fig 00: delftship software, I trimmed the model at the point where the model does not have a tumblehome, so each waterline is bigger than the next

fig 00a: delfit software using the line plan tool, I was able to make the line plan for import to ac3d.

fig 01: ac3d software: at this point I’ve already “stacked” 4 decks, and I just started the 5th. I splt the extruded polygon through the horizontal plane so the vertex’s of the top of the “polygon box” are above the plane. from the top view in AC3D I can then drag the verttex’s of the top of the box out to the new waterline plane.

fig 02: ac3D software: close up perspective view. Here I slid out each deck in a step-wise fashion so you could see it better. the next deck that needs to be fitted is hi-lighted in green.

fig 03: ac3D sofware: the 4 view screen of the same layout as fig 03.

fig 04: pepakura software: here I test unfolded the 4 completed decks. As you can see, each deck unfolded to very build-able 2d paper layout: a top, a bottom, and the sides wrap around each deck.

– Jon

[ahmad]

that’s nice workflow.

[Author]

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