Is there a way how to deal with asymmetric (with regard to x-axis, i.e. centre line of ship) regions of a hull?

[Ralph Grothe]

Hello,

for once, there are those asymmetric sterns according to Ernst Nönnicke, of which a few were faired into real built ship hulls by shipyards overhere in Germany, especially in the early 1980s.

But I’m not struggling with one of those.
Compared to the Nönnicke Stern I am currently mulling over a much simpler stern shape that I wish to capture in DS.
It is a kind of step in the transom, simple cuboid and prismatic bodies, as can be seen on this stern shot.

ShipSpotting.com

© Aleksi Lindström

How would one tackle this in DS?

Ralph

[Jesus Cruz]

You can make the layer non symetrical (layers menu), and mirror that layer, a new layer will appear with the same shape but in the negative area of the model, that layer can be modified like any other layer and you can modelled what ever you want.

Hope this helps

[Ralph Grothe]

Hello cruzmayora,

many thanks for your reply!

Actually, I already suspected that one (or maybe the only) way to deal with non-symmetric hulls in DS would involve layers.
But since my hull shapes so far have been quite simple, such as that of the German railway ferry that I currently try to reconstruct, and as I only concentrated on the hull lines (i.e. absence of superstructures, which I know many DS artists are capable of creating), I have to confess that I so far haven’t made acquaintance with layers.

Maybe, would you be so kind to tell me how I would have to define a separate layer (i.e. which grid control points of the stern should I include) and how to procede from there?

Here are a few images of my current work. I hope the BBCode works and displays the links here.

[Icare]

Hi Ralph!

You can find the explanations for new layer creation in the topic “Those-damn-chines“ initiated by Lomic.

Don’t forget: before setting a layer non symetrical, you have to disable its “hydrostatics” checkbox.

Once you drew the “half” of the non symetrical ship part, order the symetry operation (Tools tab_TransformMirror, that is the two triangles). Then select the layer(s) you whish to copy symetrically and the symetry plane (generally: vertical). Only a whole layer can be symetrically drawn, not a part of a layer. Do not disable the “Connect to existing points” checkbox, this will automatically keep the layer’s new half knited to the other side’s points.

Note: non symetrical hulls can be drawn, but the hydrostatics calculations can give strange results.

[Ralph Grothe]

Hello Again,

First, I would like to apologize for having left this thread dangling unresolved for such a long time.

I hope the people who were so kind to lend me a helping hand back then are still willing to resume this thread too.

You can make the layer non symetrical (layers menu), and mirror that layer, a new layer will appear with the same shape but in the negative area of the model, that layer can be modified like any other layer and you can modelled what ever you want.

I tried this in vain, I mean mirroring along the vertical at CL (i.e. Y offset = 0) into a *new* layer.

Well, the deselection of the symmetry check box in the originating layer0 and the mirroring worked fine.
However, what I don’t get accomplished is that the mirrored hull side ends up in a new layer.

I started renaming the initial layer0 into “Hull Port” and, as mentioned, toggled off hydrostatics and symmetric from its properties.
Then I added a new layer (which strangely defaulted to the name “layer2” where I would have assumed it to be named “layer1” if my arithmetic doesn’t fool me),
which I renamed “Hull Starboard” and which I selected to be the active one.
In its properties I also removed the checks from “hydrostatics” and “symmetric” and assigned it a complementary colour of that of layer “Hull Port” to make the distinction conspicuous.

But I haven’t found the knack to fill this “Hull Starboard” layer with the mirrored control grid.
Instead the mirrored stuff ends up in the same layer from where it was mirrored, i.e. layer “Hull Port”, while layer “Hull Starboard” remains void, even though layer “Hull Starboard” was the active one during the mirror operation.

Regards,
Ralph

[Ralph Grothe]

I have just found the answer to my last question when I was revisiting the Hull Modeling Tutorial from this site.
The trick how to get parts of the control grid at random into a new layer was revealed on page 10 of this tutorial.
According to which one needs to make the interior edges visible and select faces of it (preferably whole clusters of them by having the ctrl key pressed during selection) which should be assigned to a layer.
Having the preferred layer active during this should yield the correct assignment.
That it worked can be seen from the different colouring of starboard and port half of my hull in shaded perspective view (see attached pic).
As I have both hull sides in different layers now I can at random toggle each of them visible or invisible which will enormously alleviate the shaping/fairing of sections and waterlines of my asymmetric stern.

Attachments:

• Copacabana_2_distinct_layers.jpg

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