Full Version: Ship hull tutorials

Show messages:  1-13  14-33  34-53  54-73  74-93  94-113  114-129

Thanks! Really interesting!

G

---

OK, another issue on my next project. I'm doing a Clyde Puffer. I have the hull done and in solids. Yes, I know it could be fairer, but whatever, the master model can be sanded slightly, and these things had lumps everywhere!

I have 3 solids, but try as I might, I cannot get the two stern ones to boolean into the others. I tried Diff and Union, but no result. Why won't it do this. I can cut a line through the sterns, but I can't use this technique to trim off the ends to be flush for some reason. Nothing works again!

Thanks!

Gord.

Image Attachments:
Screenshot 2020-06-09 at 21.01.17.png 

---

Hi Gord, it's the bottom curved surface of the stern pieces. There are damaged trimming boundaries in these spots:


And there's a kind of mutated micro shelf in this area:



How did you create this piece, was it a result of a Shell operation? It kind of looks like the sort of stuff that Shell messes up on.

It's also possible that this very thin area here could be considered an area of self intersection:



It's not generally good to have opposite sides of a solid squish down to such a thin area.

If you have any earlier stages of these pieces if you can post them I might be able to tell you where things started to go wrong with them.

- Michael

Image Attachments:
gord_bad_geom1.jpg  gord_bad_geom2.jpg  gord_bad_geom3.jpg  gord_bad_geom4.jpg 

---

Yep this serial of videos is very instructive how is made a wood boat! !
(i am on 20/73...; )

And Albert Strange a cool artist and Yacht designer!
https://en.wikipedia.org/wiki/Albert_Strange

Hull Plan of Tally Ho from another cool site : https://davestallyhomodel.blogspot.com/2019/02/the-first-steps.html



Amazing stuff!

---

Thanks. Yes, it was network surface then boolean joined. It's not repairable then? I know I'm doing a difficult shame again as one part has to go down to basically nothing, whilst the other upper part has to be 90 deg. to it. Not sure what to do now. It is OK on loft, but it doesn't follow the plan shape too accurately though.

Image Attachments:
Screenshot 2020-06-09 at 22.27.47.png 

---

Maybe you can see the videos about hulls about this site (and free prog ;)
(not so easy than moi! ;)
http://www.polycad.co.uk

---

Hi Gord,

re:
> Yes, it was network surface then boolean joined.

It looks like there are just a couple of spots where the endpoints don't touch. It would probably be a good idea after you construct one of these networks that you want to join to other straight parts, to edit surface control points and ensure the end control points are all trued up to be flat so the ends will be planar.

It's probably things waving around just a little bit out of being planar that is causing enough misalignment to be problematic.


> It's not repairable then?

It might be, I'll take a crack at it.

- Michael

---

Appreciate it, thanks!

Is there a scrip I can run to allow me to see these problem areas highlighted larger? I use N, but it only shows the whole edge.

G

---

Hi Gord, there isn't any script for that, you just zoom in closely especially on corner areas where things join up. You can use the "Zoom area" tool to zoom in centered on a specific spot.

- Michael

---

Hi Gord, here is a stern piece which should be all trued up. I think this could use it here too though:



- Michael

Attachments:
puffer1.2_trued.3dm

Image Attachments:
gord_needs_truing1.jpg 

---

Hi Gord, I guess I planarized a little bit too much, I guess I should not have pulled this one up to be planar:


I was kind of thinking the upper surface wanted to be a simple straight extrusion.

- Michael

Image Attachments:
gord_planar1.jpg 

---

Hi Gord,

Your constant issues with lines not meeting or touching makes me wonder whether you have "Object Snap" switched "ON"..?
If not, then may be that could help to explain a lot of your issues?

HTH, Colin

---

Hi.

Thanks, I thought I did do - see the screenshot. Must I alter numbers somewhere?

Gord

Image Attachments:
Screenshot 2020-06-10 at 08.39.19.png 

---

Funny! Never used even don't remember that is existing! :)

Maybe because i don't use millimeter as unities
Seems all is enabled!

---

gaps and a huge amount of points on curves ... don' t forget to rebuild

the central part have issues ... lonely faces .... better to contruct this as an extrusion + boolean hole

and 2 half hulls ... union give the baby solid

i add a round piece ... à l'avant qui fend les flots ;) ( 3dm joined )

ps i can't reproduce the exact shape of your hull ... cause you post the result of the network and not the curves needed to built it ;)

---

That's awesome Michael! I have now added the raised plate that covers the join as it looks like it grew there! Many thanks!

G

---

Hi Gord, so is that going to work ok for you? Are there other problems to fix still?

So I think one problematic thing in your original one is the alignment between these pieces here:



The one on the left looks like it's trimmed off from a horizontal line:



Then the one on the right is the natural end of a Network surface:



The problem is that even if this edge:



And this edge:



Are both on the same plane that isn't going to be enough for them to get glued together well. The edge on the left coming from a trim that is interior to the surface while the one on the right coming from a curve used in Network is not going to guarantee that the shapes are going to be close enough together.

It's good for these juncture areas to be formed either by being constructed off of the same end curves, or by being intersected with each other. One coming from a trim and the other from a separate curve is not going to be good.

So if you then build separate block chunks out of these things and then try to boolean them together it's going to be something similar to this (shown exaggerated here):


And if they are pretty close to the same shape but not close enough to actually merge together, those little "shelf" pieces above are going to be really skinny slivery things which you don't want to have.

That's one of the ways things can actually get worse when things are really pretty close to matching up but just not quite enough.

The other possibility to get things like this glued together that are not quite aligned is instead of making 2 blocks right up next to each other you could leave some empty space between them and put in a transition surface like a Loft or blend between them.

- Michael

Image Attachments:
gord_join1.jpg  gord_join2.jpg  gord_join3.jpg  gord_join4.jpg  gord_join5.jpg  gord_join6.jpg 

---

That looks good now! I need to find how to get surface aligned manually. So you can't join solids and surfaces, but I still don't know why it gets out of square after I draw it on perp. lines.

Thanks, I'm sure I'll come across some other issues when my skills run out again!

G

---

If I wanted to add a plate effect, where the thing is covered with plates but some standing slightly proud. How could that be done?

G

---

Depending if you really want the physical material effect or just at the rendering ?


Only material


or simulated by textures

---

Show messages:  1-13  14-33  34-53  54-73  74-93  94-113  114-129