transom and deck

[adriano natalini]

Hi there,
as novice to Delftship free version I cannot avoid to ask for help.
From “new model” setting I am happy with the nice lines of the hull I had in mind!
Sofar so gut! Now I need to move on adding deck and transom. I can manage to move
to the center the corresponding both central lines. I need to give some camber to the deck, at this stage the deck central line, in the profile view is following the curvature of the sheer of course.
In case of transom, it’a matter of wide traditional/ racked-aft transom which needs to be rounded up on the sides. From the profile view I have a straight middle line from stern up to deck which should denote the max curvature.
Here I do not have any clue how to proceed.
What is the DS procedure?
Thanks a lot for any suggestion.
Adriano

[Hrvoje]

Hi, Adriano!

For the deck try this procedure:
* Select boundary edges of the sheer line
* then click “Edit – Edge – Extrude curved”
* in the form which pops up enter needed values
* or just accept default values.
If you don’t like the result click on the “undo” button and try some other values.

Also look at the file “Manual.pdf”, page 31, paragraph 9.5.1 Extrude.

I didn’t use transom so far.
I hope it helped. 🙂

Kind regards, Hrvoje

[Hrvoje]

Also look at the file “Manual.pdf”, page 31, paragraph 9.5.1 Extrude. 🙂

I would kindly ask the Admin of the forum to delete this post. I moved it to the previous post (to preserve the disk space B) )

Kind regards, Hrvoje

[adriano natalini]

Thanks Dida
I’ll try this.
Hope somebody else can give suggestion on transom.
Rgds
Adriano

[Hrvoje]

I found out some problem: towards bow and stern the surface of the deck is “irregular”. When internal edges are shown, is evident that some of the surfaces are triangular. When I switch Gaussian shading on is obvious why I am not satisfied. Now I am looking how to solve this.
On attached pictures you can see what I mean.

Attachments:

• Deck002.jpg
• Deck001.jpg

Kind regards, Hrvoje

[MICHAEL KERR]

Theres a tutorial on extruding a transom go to downloads–>tutorials–>reproduding an existing linesplan–>hull modelling tutorial
from experience I extrude the deck and transom in one go to avoid leak points but there is a lot of cleaning up to do so it might not appeal to you.

[adriano natalini]

Thanks Dida
it worked nicely.
But I still have lot to learn!
Now I’ll try on the transom according Mike’s suggestion
Rgds
Adriano:) 🙂

[adriano natalini]

Hi Mike,
I tried extruding transom as shown on tutorials but I get just messed up!
Maybe the example is using transom with chined boundary while mine has round boundary?!
Anyhow I am getting to the stage, as shown in the attatchment, where you can see that the centre line of the sofar added racked transom is representing a straight chine which anyhow
should represent the max curve of each waterline in the transom area.
Is there any procedure at this stage to get the water lines curved in the transom
section?
Thanks for any help
Rgds
Adriano

Attachments:

• 4078735018626Transomcentreline.fbm

[Hrvoje]

Hi, Adriano!

There are in your transom some edges you don’t need. Try to get rid of them and than continue to work on waterlines. I attached the picture where you can see suspicious edges.

You have green edges too.

In one of the posts Marven said:
“A green edge indicates you have more than two faces connected to that edge, and in that case the edge is always set to a crease edge, otherwise the mathematics of the surface are ill defined.”

Have a nice day! 🙂

Attachments:

• Deck005.jpg

Kind regards, Hrvoje

[MICHAEL KERR]

Hi Adriano,
your got a later version of Delft than me so save a version in 4.42.143 and attach it again please, you can change the version when you save it (dropdown list) you can make any type of transom there is, no limitations that I know of, it will all come in time.

[Hampus Mattsson]

I create the transom by creating a new face. First make sure your boat is the way you like it. Model the stern so that it looks nice in profile view, ten model it so that it looks nice in the body plan. You now have a big hole in the stern, the hole is the part that should look nice. Then you ctrl-select the points on the edges around the hole. It’s important that you select them in order, like when you were a child and drew lines through points in a book to make a figure. Then you create a new face from the points. The new face will fit nicely on the side but you have one edge that will most likely run diagonal. You need to split this edge and adjust the new point to fit. You will also have to turn some points into corner points depending on how you want the transom to look.

/Hampus

[adriano natalini]

Hi Hampus,
Indeed I have another hole near the bow which I wanted take care as well.
By control net subdivision you get the spots highlighed and by creating new face you get the spot sarrounded by green lines, what is the next step from here in order to get a smooth surface?
Thanks
Adriano

[adriano natalini]

Hi Mike,
sorry but I think I have to learn how to save in a different version.
Indeed clicking on the save image of the drop down list I get the window showing pixel amount in width and height. Pls let me know the next stage.
thanks
Adriano

[MICHAEL KERR]

When you have your delft model open, go to FILE –> SAVE AS down
the bottom of Save As window, left hand side you have SAVE AS TYPE
on the right side there is an arrow head click on it and all the versions will come up click on version 4.42 and save to the desk top so you can find it again, then attachment it to your post or send it to mike101@exemail.com.au

[adriano natalini]

Hi Hampus,
is there any chances you can explain better in details how to get rid of that hole?
The way I tried it didn’t work out.
Otherwise is anybody else who can help in this case?
Any suggestions?
Thanks
Adriano

Attachments:

• NewmodelSpt19.bmp

[adriano natalini]

I had some depression spots on the hull and I used “subdivision controlnet” mode.
Once fixed the problem I wished to go back to normal control net mode.
Apparently once you go on Subdivision control net mode it doesn’t seem possible to go back to the normal “control net” mode without deleting the work done?!
Is anybody aware about this? can anybody give a suggestion?
Thanks
Adriano

[adriano natalini]

I ask the Moderator

Hi Marven,
it looks like that nobody in the forum is able to help me.
I had some depression/hole on hull surface and I used “subdivision control net” for fairing and it seems to work out, but no idea whether this was the best way to go?!
I need now to work on the deck crown of each beam and on the waterlines curvature at the transom area. Do you have any suggestion how to switch off that “subdivision control net” mode to get back to the normal “Control net”. I think on normal control net mode is the best way !
It’ s avery exiting software but unfortunately there many questions and even with
DS tutorial I do not move easy forward?!
Pls also kindly let me know whether any comprehensive DS manual to buy is available
This would be also a good solution for me at this early stage.
Thanks in advance
Adriano

[Hrvoje]

Hi Hampus,
is there any chances you can explain better in details how to get rid of that hole?
The way I tried it didn’t work out.
Otherwise is anybody else who can help in this case?
Any suggestions?
Thanks
Adriano

Hello, Adriano!
The picture you attached to your message is not quite “explaining” to me. Can you attach Delftship file with a problem?

Kind regards, Hrvoje

[adriano natalini]

Hi Dida,

By the way it looks like I have 17 answers from this forum on this subject but I can only read few on the 3 pages available to open. I’ve to find out what is correct.
Anyhow thanks,
attatched pls find the model showing those depression which appears on the first stage of “subdivision control net”. I managed by collapsing those edges around the holes. After this operation the surface looks smooth again.
Now I need to go deck to give camber to each beam but not able to go back to the normal “control net” mode.

[Marven]

Adriano,

Subdividing the controlnet inserts a new controlpoint into each control edge and also into each face. So effactively you’ll end up with approximately 4 times the number of faces you started with. The new controlpoints are faired amthematically in such a way that the shape of your geometry exactly stay the same. You should only use this option if you need considerably more controlpoints because for example you need more detailed control over the shape in some area(s)

[adriano natalini]

Thanks a lot Marven for the explanation,
My problem still persists,
I do not manage how to get rid (switch off) of Subdivision controlnet and get back to normal control net?!
Adriano

[adriano natalini]

Hi
On DS free have the deck central line cambered and now would like to move on to deck crown process.
Is anybody able to suggest by which tool is the best to use to do the job?
Thanks
Adriano

[adriano natalini]

Hi there,
just closed deck & transom and would like to proceed for Bulwark&Railcap.
Thought the best way was by extruding sheer line but doesn’t work since no longer boundary edge!

Could anybody suggest which is the best option at this stage to proceed?
Appreciate any help.
Adriano

[Marven]

Thought the best way was by extruding sheer line but doesn’t work since no longer boundary edge!

Have you tried extruding to a layer that is excluded from the hydrostatics?
If an edge connects more than two faces only two faces are allowed tobe included in the hydrostatics calculations otherwise your calculations will not be valid.

[adriano natalini]

Thanks Marven,
It seems also to me that it should work the way you mention i.e. only deck layer on, I did try without Hydrostatics on but still no success: “extruding only on boundary edges”
There must be some device on which I do not realize?!
Thanks
Adriano

Attachments:

• deck.JPG

[adriano natalini]

By the way the line was turned into yellow of course
Adriano

[adriano natalini]

Well .. the only option, meanwhile I found out, is to go back to earlier stage i.e. before closing the deck, here it works fine.
If anybody knows other option to build up on the sheer line after the deck is in place I would appreciate any suggestion Thanks
Adriano

[Marven]

A possible workaround:

1. Move the deck to a layer that is not included into the hydrostatics
2. Extrude the bulwark to a separate layer. Exclude this layer from the hydrostatics
3. Then modify the “hydrostatics” property from the deck layer so it is included in the hydrostatics calculation

Note: It’s crucial that of each edge (in this case the sheer line) with more than two faces connected a maximum of 2 faces is included for the hydrostatics calculations

[adriano natalini]

Thanks a lot Marven,
sofar I am still working on bare hull without deck anyhow it doesn’t seem to me (sofar!) to have real any disadvantages! I’ll try the other option later.
adriano

[adriano natalini]

well… am pretty happy sofar with the modelling of the bulwark on the sheer line (no deck in place) but now I am facing the basic problem of distorted grey lines (frames) whenever I insert new control points!
For sure there is a way to avoid it(feel “locking” isn’t the correct tool?!) or bring them back to the original shape?!
If anybody can give any suggestion, it will be very appeciated.
Adriano

Attachments:

• distortedframelines.JPG

[Marven]

This usually happens when you use faces with less or more than 4 points. You should avoid this where possible.

[adriano natalini]

Thanks Marven,
I understand that but whenever I have to shape boat parts as shown on the attatched pictures, how can I use only 4 points on a face?!
Any other option to overcome the problem?
Thanks

Attachments:

• quarterdeck.JPG

[adriano natalini]

by mistake same picture was attatched
Adriano

Attachments:

• quarterdeck1.JPG

[adriano natalini]

Am on DS free,
does anybody know, apart from the use of Screen compass, which way on DS is possble to give crown to a deck?
Thanks for any suggestion
Adriano 🙂

[Marven]

Select your deck edge, and then use the “Extrude curved” command from the edge menu. This will extrude your deck edge along a circular arc

[adriano natalini]

Thanks a lot Marven
I do use that to shape the deck central line which is pretty good and fine but do not think is suitable for what I need now,
most probabily I did not explain quite correctly:
I need to shape the deck curve at each section (deck beams) as well waterlines at the transom,
I thought “create a deck by extruding edges along an arch” tool might be the right one?!
I did try it but no success.
Thanks in advance for further help.
Adriano

[Marven]

I did try it but no success.

What went wrong?

[michiel bonke]

Hi adriano,
I’m new to this forum, but I designed some yachts with DS pro. (some of them are on the model-database page).

Maybe this works for you:
1. remove the deck (this can be done by showing the interior edges, selecting the interior edges of the deck, and deleting them)
2. create a new controlface by selecting the control points of the sheer line and the upper edge of the transom (be sure to select the control points from the stem to the transom in the right order).
3. the result might look odd but this is quickly repaired:
4. select the edges of the sheerline and the upper edge of the transom
5. make these edges crease again (knuckle lines)

now you have a very simple deck.

6. now you can add control points to the centerline of the deck (as many as you have control points in the sheerline)
7. connect them to the control points of the sheerline with a new edge
8. use the copy values to other points button to set the control points to the same x coordinates (be sure to select the control point of the sheer line first, otherwise the control point of the sheer line is altered instead of the control point of the centerline of the deck)
9. repeat this for all the sections or “deck beams”
10. then add new control points to all of the transverse edges of the deck
11. connect the new points with a new edge from stem to transom
12. move the control points of the deck to your desired height

if you need more control of the deck you can repeat step 10, 11 and 12 to create more longitudinal edges

I hope this works for you

succes, michiel

[adriano natalini]

Thanks Marven,
“No success” was in the sense that I did not manage how to use this tool.
If you could give me few tips I would very much appreciate.
Adriano 🙂

[adriano natalini]

Thanks Michiel very kind of you.
I’ll go through that and try it!
Adriano 🙂

[adriano natalini]

URL : http://www.delftship.net/delftship/index.php/forum/hull-modeling/2014-transom-and-deck?limit=6&start=36#2345

Hi Marven,
Just received this a.m. e-mail but cannot find any new message on the forum?!.
I get only up to page 7 (no further pages available) of my topic with the last message no. 2344.
Pls kindly check whether it’s a problem on my end?
thanks
Adriano

[Marven]

Hmm. don’t know what happened there.

I’ve uploaded a small video showing how to create a curved deck.
You can check it out here

[adriano natalini]

Hi Marven,
Well.. sofar I still cannot see yr post 2345.
Yesterday strangewise I tried to get on the Forum but somehow the web site wasn’t available
for several hours. Do not know what was the reason.
If you’re kind enough maybe you can try to resend it?
Thanks
Adriano 🙂

[Hrvoje]

Hi, Adriano!
The answer 2345 is not visible, probably deleted. 🙂

Kind regards, Hrvoje

[adriano natalini]

Thanks Dida,
It looks like that, strangewise. Hope Marven is able to resend that post.
Adriano

[Marven]

There was a problem with the website yesterday, so I had to restore a backup. I’m afraid the message has been lost. I’ve checked all my backups but I’m unable to find it in any of the backups.

Sorry guys :blush: ..

[adriano natalini]

Thanks Marven for yr efforts.
That’s a real pity ! that video could have been of great help.
Whenever you have , at yr convenience, any other option it will be very much appreciated.
Rgds
Adriano

[Marven]

I was referring to post #2345.
the video can be found in the video section. At the moment it’s the only vifeo, the idea is to upload more.
Perhaps you guys have suggestions on what you would like to see demonstrated….

[adriano natalini]

Fantastic Marven!
I just watched the video, I did not think it was that simple creating a curved deck!
I may give you some input next for more videos.
Well done, thanks
Adriano

[MICHAEL KERR]

I’ll watch any videos you upload Marven, as long as you promise to keep your cloths on.

Mike :whistle:

[adriano natalini]

Hi Marven,
I’m facing following question :
Extruding bulwark along the sheer line is not that difficult but once you want the bulwark follows , let’s say, a different path (line) what is the best process?
Indeed, in my case, I would like to change at the transome the bulwark corner joints (as from the attatched screen shot) from corner to rounded up joints.
can this be explained in a video?
Appreciate yr help
Adriano 🙂

Attachments:

• bulwarkjoints.JPG

[adriano natalini]

Hi there,
I did created a curved deck as per “extrude curved command” which is very pratical & simple.
Now I need to create a curved transom. I did try at same time of deck extruding but it doesn’t work since the curvature leans towards inside the hull, I need opposite.
I did try to extrude curved separately after the deck by many different trials and ways but it seems to me that it doesn’t work?!
Is there any tool or way which I am not awere of to model a curved transom?
Appreciate any help, thanks
Adriano 🙂

[Marven]

Have you tried adding a (vertical) cylinder in a separate layer and intersecting this layer with the hull?

[adriano natalini]

Hi Marven,
I did not try this, haven’t gone yet through the cylinder tool which have to do soon or later.
I think that using “screen compass” in this specific case might be easier for me.
Anyhow thanks, very much appreciate any of yr suggestions!
Adriano

[adriano natalini]

By the way Marven
a short video on how to use “add a Cylinder or box” would be useful.
It doesn’t seem to be that easy as in case of Keel & rudder tool.
Thanks in advance
Adriano 🙂

[adriano natalini]

Hi there,
is anybody can exlain basically how to master “add Cylinder” tool?
I would appreciate any help! Thanks
Adriano 🙂

[adriano natalini]

Have you tried adding a (vertical) cylinder in a separate layer and intersecting this layer with the hull?

Hi Marven,
I did try to model the curved/inclinated transom by “add cylinder” tool.
In this particular case it looks like it’s allmost impossible due to the inclination to get the cylinder perfectly fitting the transom shape!? Indeed despite lots of hand adjusting of both cylinder and transom I cannot get closer than as shown on the attatched file.
At this stage, by intersecting layers, only a distorted transom will come out (obviousely transom edges are adjusted to the adjacent cylinder intersections).
Am I doing anything wrong?
or what would be the alternative to close an inclinated curved transom?
Thanks for any comments 🙂

Attachments:

• 4085282612944fairedhulltransommodeling.fbm

[John R. Coil]

While it has probably been suggested before: I would suggest defining (in its own layer) a curved surface in either the horizontal or vertical orientation that has the curvature you desire and then rotating and moving it into final position. This greatly simplifies the math involved. For example, to get the values for lateral displacement (Y) for a plane of a given radius formed by rotating around the vertical (Z) you use this formula:

Yd = Rz(sin(acos(Xd/Rz)))

… Yd is transverse displacement, Xd is lengthwise displacement, and Rz is the radius rotatied around the vertical axis.

… which you can use as starting point to plug into the Web 2.0 sci calc here ( http://web2.0calc.com/ ) if you don’t have a scientific calculator of your own. The nice thing about it is that it has a memory so you can pull up the last attempt and input your new lengthwise value and then hit equals.

The last time I used this it was with a radius of 4.8333′ for a forward cabin roof line. I put my control points at 4.7333′, 4.6333′, 4.4333′, 4.2333′, 4.0333′, 3.8333′, 3.3333′, 2.8333′, and 0.8333′. This curve, combined with the point in the middle, defined in a fair surface to work with.

The math for finding the values for control points for curves based on ellipses is somewhat more involved but work more of less the same way and the above calculator is up to it.

Generally, I find that a radius equal to the width of a transom (or even less) is minimal, and can result in dramatic sweep around at the sides — all you really need is enough surface to cover the while thing. One that is half again (or more) than the width of the transom seems to yield more classic looking results. As with all things, this is a matter of personal taste. Ditto for negative camber in a swept forward transom (I think of a classic transom as aftward slope, modern sailboat transoms as forward).

To insure proper placement after defining the basic curved surface I would recommend first rotating said surface to its desired angle (either forward as is common today or aftward as was the norm in days gone by) and then use the values (x,y,z) of 1 control point on the centerline of your surface as the starting point to move the whole layer … matching that up to the corresponding center point on either the sheer line or the keel as desired. If you want to match points both at the sheer line and keel you’ll have to play around with the angle until it’s good enough or you just don’t want to mess with it any more.

Then find the intersection points in your transom and trim the excess. Ditto for your hull.

Naturally, I recommend saving the work in iterations in different files. That way you can back up at any time and not be committed until you want to be.

[adriano natalini]

Many thanks Rurudyne,
well.. it does sound easy for you but not simple for me.
Am novice to cad and DS and no teatcher, not easy to move forward!
Unfortunately I do not know how to model a curved surface separately (most probabily starting from a cylinder?!) Definitely mastering math formulas lot of things can be achieved but through this path there is long way to go for me.
Now down to earth, the way I am doing isn’t that much far?!

-After modeling hull including approx. transom side sweep
-Close the deck to get the the top transom curved edge
-from plan view hand adjust aft deck y-axis curve (it could be a regular or ellipse kind of curve)
-From the body plan view I have a full contoured transom which needs now to be closed
-by inserting proper control point values (top aftdeck cl and keel cl points) achieve a matching inclinated cylinder of course on a separate layer, which intersects the hull aft end
The main problem for me is to match the desired transom radius due to the inclination, nevertheless both hand adjusting (compromising) “trial&error” hull to cylinder or cylinder to hull is a tedious job which can easily bring to a mess.
I suppose yr way would avoid lots of hand adjustments and messing around!
If you’re a patient guy and have some more time to spare to try to explain how to model that curved surface separately (without involving too much math) I would very much appreciate.
Anyhow I thank you somuch for yr kind efforts.
Adriano 🙂
Adriano

[John R. Coil]

I can help you get started as it isn’t hard. Please note: I’m probably going to include a lot of info you already know but that’s because I’m trying to be complete.

First you need a layer to dedicate to the surface you will make to be your transom.

If your tool bar above your model is set up as per the program’s default you will see a bar that contains the following:

• a small plus sign in a green circle in front of a red dash-line box,
• a small minus sign in a red circle,
• a figure that looks like an index card,
• a grayed out -thing- that is meant to look like a stack of stuff,
• a selection box with something like “Layer 0” showing,
• and finally a block of color

This contains some of the same options found in Edit > Layers > Dialog that you presently need.

Click on the green plus sign option to add a new, empty layer.

Select this later and then assign in a color that is (for the moment) different than the rest of your model (I do this to make it easier to judge what it’s doing later when I’m rendering).

Name this layer “transom” — or whatever you want.

With this layer chosen this is now the active layer in your model and any new face you put into it will go here — that way when you later move it around it will be all you are moving around.

Now add 4 control points making sure the surface that they will form will be more than adequate to cover your whole transom.

For my example I’ll just use dimensions similar to those I’d previously mentioned: where the radius of the transom is 4.8333′ and say, just as an example, it’s for a transom that will be 8′ across and 5′ high and which I intend to be swept aftward at a decent rake.

Because I’m going to rotate the critter into place the control points need to be farther apart in the vertical direction than the transom is high: so I’d set 4 new CPs at (0,0,0), (0,4.8333,0),(0.0,10),(0,4.8333,10). It’s better to just make the thing too big in the vertical direction at this stage since adding points later would be a hassle.

Now select all four control points by clicking on them while holding down your control key. Once this is done you will see an option on your tool bar that looks like a yellow dot inside a square light up: click on this to create a new surface from your 4 control points.

Since you’ve done this while your “transom” layer is selected this new layer will be the only thing in that layer (remain in the transom layer).

Now you need to set all 4 control points as “corners” so you are looking at a rectangle rather than a oval.

Select the top and bottom line and create two new control points by splitting the control edges in two (the option looks like a line with a dot in the middle and an arrow points to the dot),

Select these new CPs and connect them with a new control edge (the option looks like a box split by a diagonal line).

Now pull out your own scientific calculator OR go to the Web 2.0 Scientific Calculator I’d given a link to earlier — I’ll proceed as if you’re using the online tool.

The equation I gave you, Yd = Rz(sin(acos(Xd/Rz))), is what we’ll use.

You want Yd so don’t worry about typing anything for it into the calculator.

Rz = 4.8333 and Xd is the changing value of X that you will assume to set the control points for your surface.

It is also important to adjust things to take into account the fact that your surface is to the left of where your radius starts, so “Xd” is really “(4.8333 – Xd)”.

What you will type into the calculator the first time will therefor be:

• 4.8333 (sin (acos ((4.8333 – 0.1) / 4.8333)))

… I kept spacing in just to make that easier to read.

When you press the equals key you will get a result, rounded to the nearest value, of 0.9781.

This means the two CPs in the middle of your face are to be changed to (0.1, 0.9781, 0) and (0.1, 0.9781, 10) respectively.

Now repeat where you split the edges and inserted a new edge.

In the Web Calculator you will see a selection tool with some numbers in it, use that to pull up the equation you just used BUT change the “0.1” to a “0.2” before you hit the equals key again.

The values for these new, new CPs will be (0.2, 1.376, 0) and (0.2, 1.376, 10) respectively.

Repeat as needed for different Xd values to form the curved surface — using the original outermost CPs of your surface at the last.

In the example above this gives me a curved surface defined by the following CPs connected by vertical edges:
(

• 0, 0, 0) and (0, 0, 10)
• (0.1, 0.9781, 0) and (0.1, 0.9781, 10)
• (0.2, 1.376, 0) and (0.2, 1.376, 10)
• (0.4, 1.9253, 0) and (0.4, 1.9253, 10)
• (0.6, 2.3324, 0) and (0.6, 2.3324,10)
• (0.8, 2.6633, 0) and (0.8, 2.6633,10)
• (1, 2.9439, 0) and (1, 2.9439,10)
• (1.5, 3.5, 0) and (1.5, 3.5, 10)
• (2, 3.9158, 0) and (2, 3.9158, 10)
• (3, 4.7609, 0) and (3, 4.7609, 10)

That’s (almost) all the plugging and chugging you need to get your transom.

Next you need to be sure to Selection > Deselect All if anything is still highlighted — this is just a clean up to make sure the only thing you’ll be rotating is your would be transom.

To rotate the transom go to Transform > Rotate.

A pop up will appear showing the different layers you can rotate: make sure that the “transom” layer is the ONLY one still checked before you press okay.

The next pop up will give a place to input rotation around the X, Y, or Z axis. In this instance you will be rotating the transom around the Y axis so input the angle (either forward or backward) that you want your transom to have. I believe, if memory serves right, that a positive angle will result in an aftward slope of the transom and a negative angle a forward slope of the transom.

Once that is done you need to move the transom to the right place.

To have the transom to positioned relative to the sheer line highlight the CP that used to be at (0,0,10) and write down its new values. Next highlight the point on your deck where the transom will end at the middle of the hull and write down those numbers.

• Alternately, if you want to have the transom positioned relative to the keel use the CP that used to be at (0,0,0) and the one along the keel where you want your transom to start — otherwise the procedure is the same from here on out.

FIgure out how far, and in what direction, you would need to move the CP on the transom to be at the exact same location as the CP on your hull (write that down). This will be the last bit of math you need to perform.

Make sure to Selection > Deselect All at this point so you aren’t moving more than just the transom.

Transform > Move and, as before, make sure that the transom layer is the only layer still checked before you proceed.

Input the values to move your central CP that you came up with earlier.

Now you have a curved surface representing your transom that has the shape you want and is in the position you want.

Next you need to trim the excess so Edit > Point > Intersect Layers and put new CPs in your transom where it intersects with the hull. You may need to repeat this step if you’ve got a deck that’s in a different layer than the hull proper.

Doing this inserts CPs and edges into your transom that has the shape of the hull.

You should also Edit > Point > Insert Layers to put new CPs into your hull (where it intersects with the transom) too. If you do this now be sure to select the proper layer of the hull to make that the active layer before you do so.

After you do this be sure to return again to the transom layer as the active layer before proceeding.

Just to make things easier in the next step I like to move just the transom (or whatever surface I’m working with) a fair distance away from the rest of the model. I do this because I’m deleting stuff and I don’t want to delete part of the model than needs to stay. 10 or 20 feet up usually does the trick.

Once it’s out in clear space with nothing around it to get selected and deleted by accident all you need to do is select everything outside of the final shape of your transom and Edit > Delete it.

If you find that some CPs and / or edges are missing look for the comparable CPs and edges on the hull as these, taking your moving the transom into account, these have the same locations as their twins on the transom,

So if you have to put in any missing points / edges by hand at least you know that they’re in the right place.

Once you’ve got the transom cleaned up do the same with the stern of your model.

FInally move the transom back to where it should be by reversing what you did to get it out in the clear and you’re done — you’ve got a fancy curved transom.

If you look at my “San Jacinto” in show me your ships you can see what all this plugging and chugging can accomplish. A newer version (not shown right now) improves on that one by having the keel line crease starting aft of the water line so that the transom now sweeps down to a fine point rather than be flat along its bottom.

[adriano natalini]

Woh… Rududyne you’re a real patient teatcher!
I didn’t expect that much!
Give me some time to absorb all that stuff. :blink:
Appreciate yr time.
Adriano

[adriano natalini]

Hi Rurudyne,
Just started to go through yr suggestions but soon I find out that some questions would arise.
I find that it would be much more convenient, if I could ask you questions directly though yr e.mail id.
Of course if you do not mind it! I would appreciate yr further help.
Thanks in advance
Adriano 🙂

[adriano natalini]

my e.mail ID : np.design@usa.net

[John R. Coil]

Hi!

I’d be willing to answer any of your questions that I can answer; however, I’d rather do so on the forum.

Partly because, if I can answer it, it may help others with similar questions.

But also, and this is important, if I can’t answer a question someone else might and we’d both be helped.

Now, having said that: after I posted that how-to I remembered a few addendum that can’t hurt sharing.

First off, the formula for finding the offsets for a curved surface the way I showed you is also useful for obtaining the offset values for curved deck with a constant radius — even when the sheer line is something saddle-like as Rhodes and other classic designers used. Remember to use large radii to do this. The trick here is to start by assuming the sheer line, and your radius, and then working back towards the center of the ship.

But as far as transoms go you can obtain somewhat different results by independently moving the upper line of your transom layer to its location on the sheer line and then moving the lower line to its position on the keel like. Compared to rotating the surface and then moving it the result here will have less of an upswept feel to the transom.

Also, if you want your transom to both start and end at a particular point and like the upswept feel that rotating comes with this can be easily achieved by first choosing an angle to rotate the transom through that seems like it would be close enough and then hand selecting the edge less precisely placed and moving it however far you need to nudge it to get it on target.

Time permitting I’ll pull up a model and produce a number of different transoms to show what effects, that I know how to achieve, may come out.

There are, of course, certainly other tricks to be used: that I can’t describe (having not used them even if I may think they’ll work) or even know about … for example, I’ve suspected — though never attempted — that this may help in producing a rounded stern. As for what I don’t know: “I don’t know what I don’t know.” — James T. Kirk … to which I’d add: “I suspect it’s rather a lot though….” 😉

[John R. Coil]

I realized that I didn’t actually have to finish a transom to show what sort of results you can get.

I also realized, now that I put the results side by side, that rotating or not doesn’t make much difference … sort of a “Homer moment”.

Here’s what I came up with using a minimal radius of 6’6″ where the transom itself (if left intact) would be 4’10”.

All the red aft of the green surface would get cut away if the model were completed on the basis of that transom.

Double that radius to 13′ and this is what I got:

Depending on the effect wanted I could go with an even wider radius for an overall flatter transom or I could do something between these two … possibly in an effort to keep some of that lower line on the narrow radius version without having quite so much cut away up higher.

EDIT: I just realized I’d forgotten something important. Throw in at least 1 extra control edge very near the center so the resulting transom doesn’t end up with a hard chine down its middle.

[adriano natalini]

Hi Rurudyne,
I do understand it and appreciate yr views.
I was meaning that only for the sake not to”invade” too much the forum with possible simple questions that’s all. Anyhow very happy to have somebody who can help no matter which way!
That’s very encouraging and would help me to go a considerable step ahead!
Now:
There is no problem with layer’s matter, but I need to understand first the interface you start with.
f.e.I have my screen with the model on which I make everything invisable eccept grid, it doesn’t seem to me to be the correct “drawing board” since no edge between control points is allowed eccept I’m missing something.
So pls, if you’re kind enough, whenever you have time to spare, any tips in this regard will be wellcome. (screenshots of course are of great help)
Thanks
Adriano

[John R. Coil]

If I read you right what you need to do is insert an edge at the intersection of your layers.

You can do this by selecting Edit > Points > Intersect Layers.

The pop up will ask you which layer you want to put new control points into and which layer you want to use as basis for those points. When it does so it will tend to insert the control points you need but if you’ve used different layers for different parts of the hull (like having the “hull” and “deck” is separate layers) some lines may be left out that need to be manually inserted. Ditto for where these new details join to the centerline of your model.

Once that is done you should have something to see.

One thing I have learned by trial and error is that if there is no intersecting edge to intersect the program doesn’t generate any detail there. Since the surface you are using for your transom may lack control edges exactly where it passes through the hull to the extreme left and right of same this may result in alack of usable detail.

At this point you can do two things. The first, which is probably easiest, is to make sure you’ve got all the CPs you need for your transom on your hull and then, rather than making new matching detail by copying CPs on the hull to the curved surface (which is the other option), create a new face spanning the CPs for the transom in the hull by selecting all the CPs one to the next and then using EDIT > FACE > NEW. When you do this you’ll have to re-crease your edges and re-check any corner boxes that may have become unchecked. Also, since the new face is curved it would be a good idea to span it with control edges.

I hope that helps.

Aside: one thing you may want to play around with later is WHERE you put those creases on your hull. I’ve discovered doing this can create some interesting and desirable effects. For instance the only difference between these two transoms:

… and …

Is where the creases have been placed. On the first version they are at the transom control edges itself and the result is sharp edges. With the second version you can see the where I’ve placed the creases as black lines — back 1 level deep into the model — and the result is that smoothed shape. Considering that this particular critter is a sort of hybrid between an oversized kayak and a skiff for sailing (one with delusions of grandeur) the latter looks promising to me.

… that it’s small enough that I might even be able to afford to build it at some point … well that’s another matter….

[John R. Coil]

If I read you right what you need to do is insert an edge at the intersection of your layers.

You can do this by selecting Edit > Points > Intersect Layers.

The pop up will ask you which layer you want to put new control points into and which layer you want to use as basis for those points. When it does so it will tend to insert the control points you need but if you’ve used different layers for different parts of the hull (like having the “hull” and “deck” is separate layers) some lines may be left out that need to be manually inserted. Ditto for where these new details join to the centerline of your model.

Once that is done you should have something to see.

One thing I have learned by trial and error is that if there is no intersecting edge to intersect the program doesn’t generate any detail there. Since the surface you are using for your transom may lack control edges exactly where it passes through the hull to the extreme left and right of same this may result in alack of usable detail.

At this point you can do two things. The first, which is probably easiest, is to make sure you’ve got all the CPs you need for your transom on your hull and then, rather than making new matching detail by copying CPs on the hull to the curved surface (which is the other option), create a new face spanning the CPs for the transom in the hull by selecting all the CPs one to the next and then using EDIT > FACE > NEW. When you do this you’ll have to re-crease your edges and re-check any corner boxes that may have become unchecked. Also, since the new face is curved it would be a good idea to span it with control edges.

I hope that helps.

Aside: one thing you may want to play around with later is WHERE you put those creases on your hull. I’ve discovered doing this can create some interesting and desirable effects. For instance the only difference between these two transoms:

… and …

Is where the creases have been placed. On the first version they are at the transom control edges itself and the result is sharp edges. With the second version you can see the where I’ve placed the creases as black lines — back 1 level deep into the model — and the result is that smoothed shape. Considering that this particular critter is a sort of hybrid between an oversized kayak and a skiff for sailing (one with delusions of grandeur) the latter looks promising to me.

… that it’s small enough that I might even be able to afford to build it at some point … well that’s another matter….

[adriano natalini]

Hi Rurudyne,
Thanks a lot for the detailed explanations and interesting tips.
Actually I wasn’t that far but meanwhile I’ve overcome the problem.
Now I am not so sure whether you start from vertical (to base line) surface or not?!
Definitely, straight away we can give the surface the desired inclination as shown from my attatched picture. At this stage, I wouldn’t see much difference by using “add Cylinder”tool here I have to match by trial and error the radius but that’s all! Since, in my particular case, it’s matter of a regular surface of an inclinated cylinder, whatever small or larger, which I am fine with.
My question is: what is the advantage by using curved surface by help of sci calc vs. cylinder?
May be it’s a stupid question but, if you do not mind, I need to understand it properly
Thanks in advance for yr kind comments and patience.
Adriano 🙂

Attachments:

• step1surfacetomodeltransom.JPG

[John R. Coil]

I can tell you one advantage of using a curved surface rather than a cylinder: with a cylinder it’ll have the opposing surface that intersects your model so that when you intersect layers it will put points there too. These can sometimes have an effect on the way a model renders.

Now, about getting that first curved surface.

Yes, start with a vertical plane.

And, another Homer moment here for me, you really don’t have to worry about the math or the scientific calculator so much. Remember those offsets I gave you for a radius of 4.8333? Well, once you’ve got a surface typed in using those values you can scale it (Transform > Scale) in the X and Y direction to get any diameter you may want. Just use your ordinary calculator to divide the radius you want by 4.8333 and then use that number for the scale function.

Also, I found I need to correct something I wrote earlier about the math for ovals being more involved. While this is certainly true what I realize now is that rotating the circle results in oval shapes if you were to cut a horizontal or vertical cross-section through it. You vary the actual shape of the oval by increasing or decreasing the angle of rotation.

Which means that selecting all the CPs on the top of your curved surface and Transform > Move them into place on your sheer line and then to do the same with the bottom of your curved surface, moving it to the place you want on the keel, is how you actually get a true-circular surface cutting through where you want your transom to be.

This last has also proved an easy way to use different radii — you can scale the top line and bottom lines independently of each other. Doing this seems to give you control over two other important aspects of any transom: where it connects to the sheer line and how far forward it sweeps. For example, say you wanted the sheer line to join with the side of the hull 2′ forward but doing so makes the thing sweep around dramatically and it just doesn’t look right. If you made the radius of the lower edge of your surface larger you can try to tone down this effect if it is unwanted. In this last instance I “know” it’ll work but I suppose it depends on the model and your preferences how much can be achieved with it.

[adriano natalini]

Thanks a lot again Rurudyne for yr kind efforts to help!
Last night after sending out the post I was playing around with that flat surface.
Actually I am not bound to any fixed radius, therefore I tried to model the surface by hand adjusting both transom edge to the curved surface and vice-versa as per attatched screen shot. It might sound a short cut of yr method but it appears to me (at least to my experiences) to be pretty pratical since I can adjust any spots around the transom until it pleases my eyes and straight away!
After intersecting the layer I’ll get the new shaped transom picture and if not yet happy I can work on it again?!
Definitely with this software there are lots of options to work around problems just need “simply” how to master them! Anyhow it’s very enthusiasming whenever I can see any small piece added to the boat!
I would be pleased to have yr opinion about any possible “reverse side of the medal”.
Adriano : :unsure:

Attachments:

• transommodelingbyfreehandcurvedsurface.JPG

[John R. Coil]

It looks really nice! The combination of the pronounced tumblehome and the relatively deep-V at the keel should make for a gorgeous transom.

Aside: looking at that image made me realize that there may be a secondary use for the curved surface we’ve been talking about — to help define the on-deck line of any railing for a cockpit if it were set away from the sheer (and its surface if it were a solid rail with a aftward slope that matched the transom, a style I seem to remember seeing). That way it would be based on the exact same shape as the transom at the sheer but could vary to match what the deck was doing.

[Hrvoje]

I was referring to post #2345.
the video can be found in the video section. At the moment it’s the only vifeo, the idea is to upload more.
Perhaps you guys have suggestions on what you would like to see demonstrated….

Hi Marven! Can you make a video “How to make inclined frames” (not 90 deg. to longitudinal plane)?

Kind regards, Hrvoje

[adriano natalini]

Many many thanks Rurudyne,
that curved surface tool either ways is very helpful and for sure I’ll have opportunities to use it “on board” again. I appreciate yr help because not easy to get it generally from the forum, not many members are able or willing or waterever to help or even just simple comments would be appreciated, even from the administration side little more assistance would be wellcome!.

Anyhow, you’re far more expert than me and would like to ask you another suggestion if you do not mind:
If I have to work into fine design details (I do not know how far fine details can be achieved by DS ) but I cant use extra control points on the normal control net!
f.e I would like to work and refine the bulwark ends, would be the only or best way
by adding a box, of same dimantions as bulwark of course, on an extra layer, use “subdivide control net” tool and work on it?
By the way I am working on my dream sail boat modernclassic, very much influenced by those beautiful old American Grand Banks schooners! I love them!
I do not want take too much of yr time you can answer simply yes or not.
Thanks
Adriano 🙂

Attachments:

• modelinginfinedetails.JPG

[John R. Coil]

I may have been a bit farther along on one specific thing but as far as fine deck details go I’ve got no real advice of my own to give …. BUT not too long ago someone uploaded their model of a 16m race cruiser to DS’s gallery here on this website (the file name is S+Spant+1600, you can find it by clicking on “Downloads” above and then the side bar that links to the gallery) that included clear portals, the tiller, and other nice details. In the spirit of “good artist copy but great artists steal” I down loaded it in hopes of figuring out how they did what.

THAT guy knows his stuff.

[adriano natalini]

HI Rurudyne,
Thanks for yr comments.
Indeed I had seen it already, nice sail yacht! I owned similar vintage (1905) sail yacht with bow sprit nice times, lots of work on board!
I assume the only way would be to separate the details on a layer and get subdivided control net.
I’ve to go for trial&error of course.
Another issue for which right now I’m breaking my head, I just face problem in deleting transom eccess from the hull?! :angry:
all control transom points are on, layers on I go to Point>intersect layers>insert new control points in hull and find intersection with transom! but nothing happens!? This is the correct way, isn’t it? :unsure:
If could give yr opinion it would be appreciated.
Adriano

Attachments:

• intersectinglayers.JPG

[John R. Coil]

The problem you are having is the lack of control edges in the plane used as intersect layers will only insert control points along existing edges.

Since your hull at the transom is the shape you want it to be another way to get your transom is to create a new face directly from those CPs. I find that it looks prettier if you subsequently connect the CPs across the new face … otherwise the rendering will come up with its own control net and those can look a mite goofy. Unless you were using compounded curvature you only need to do this in the vertical-ish direction (not all lines will be straight up and down. Then you can do away with the curved surface you used to get those point on the hull during cleanup.

Aside: came across this old joke again the other day and I’ve been wanting to pass it along.

Three men — a mechanical engineer, a chemist, and an economist — were out sailing when a storm wrecked their boat and left them stranded on a remote island. Fortunately the boat’s owner, the engineer, had thought ahead and had a supply of canned goods for emergencies … unfortunately he only thought to buy an electric can opener and it was on the bottom anyway since no one had grabbed it while she was sinking.

“This is not a problem!” the engineer wanted to sound upbeat, “I mean, sure we don’t have a can opener and nothing to make a can opener with but back in the 19th century people were opening cans for years before can openers were around so all we’ve got to do is find some suitable rocks and have at them till they break open.”

“Too much work.” the chemists grumbled, “We should start a fire around the cans. When the contents boil as they cook the pressure will blow the tops off the cans and then we can eat.”

“Sound dangerous.” the economists countered, “But if we assume a can opener….”

[adriano natalini]

Sorry to keep you busy!
Thanks for the joke!
Definitely I would like to keep the actual transom shape but even if, for trial, I move the curved plane well further forward it doesnt’ work?! There could be something else which I am missing?
I’ll try yr suggestion if I did understand correctly.
Adriano

[adriano natalini]

Hi Rurudyne,
hope you didn’t miss me!
Here am again.
I got created a new face directly from the actual desired transom (shape) control points, as shown on the attatched screen shot, which is flat with a crease in the middle. Sofar I managed but cant go forward.( The line between two control points is not turning red because the two points weren’t properly placed on the original ones. May be I need to start again from the beginning to create the face!)
Now how do you mean “to connect the CPs across to the new face”? Do you mean with the curved surface? if so, how? 🙁
Sorry for bothering again.
Thanks
Adriano

Attachments:

• transomconstrolpointsonnewface.JPG

[John R. Coil]

Hi! No bother at all. 🙂

If I recall correctly from your more recent attachment the angular results are possibly a result of you using a plane that is flatish (at least it looked that way to me).

If that’s the cause you will need to break that plane up into chunks and induce a curve if you want a curved surface. You can use the offsets I gave early on (for a radius of 4.8333) and then scale the resulting surface in the X and Y direction to achieve any radius you want (unless I’m mistaken scaling in only X OR Y, for non-uniform scaling in X and Y, will produce some form of oval rather than part of a circle). With CPs only on the upper and lower edge of a face you can scale them independently of each other.

Alternately, if you don’t need an exact size, add just two new edges to that surface. One should be moved very near the centerline and is there to assure a rounded surface and the other is kept at the same X value as the CP on the center line but is moved out Y. Make sure that neither of these new edges is a crease and you should get a curved surface whose curvature you can play around with by changing how far out Y the “midspan” control edge is.

About adding edges to the face that forms the transom: when you first form a new face from a group of selected CPs using EDIT > FACE > NEW FACE the program somewhat annoyingly looses all crease info for the old edges at the juncture of the new face of your model. Once you re-crease these turn on the feature that lets you see “interior edges” which will show you where the program is inserting detail into your model to determine how it will render your boat. If you look at your transom you should see it attaching most every CP defining the edge of the transom with every other CP defining the edge of the transom. It does this because the surface isn’t either flat or rectangular and the program is trying to come up with a surface based on the information it has. The trick to getting better results is to give the program more information and this is what I was talking about.

I find it easiest to start with CPs closest to the centerline. Select the CP closest to but not on the centerline on the top and bottom respectively and add a control edge between them. Then move to the next pair of CPs in order. You will see the “interior edges” settle down a lot and, also, they will no longer be drawn as straight lines across your transom which will cause a crease at the centerline edge as well as a pincushion effect that you should have seen.

In your specific instance you may find it helpful to selectively add a CP or two to your bottom edge to give lines attached to CPs of the top edge somewhere to attach to. Also, not every CP needs to be so attached … though if one does or not is a situational judgment call.

I’m guess this latter approach is what you may need to do.

Hope that helps.

[adriano natalini]

Hi Rurudyne,
I am very thankful for all yr efforts and time spending here and sometime feel uncomfortable if I cannot interpretate or use yr instructions completely in a correct way and this due to several factors.I think mainly due to the fact that I did follow yr instructions but somehow the result is not there , sometime due to some wrong hidden interactions which are not allowing to move ahead.
I just descovered one. Indeed I do now get an intersection on the hull but only up to certain point.
The problem is caused by the fact that I did model the quarter deck and bulwark previousely not correctly.
Since we need, when closing the transom, the deck crown line, q-deck in this case is approx. 10 cm. higher than the main(fore) deck, so I had extrude the sheer line up to the quarter bulwark and the close the deck. It seems to be a tricky interaction since my main bulwark is running aft (under the quarter deck area) only ornamentally (old classic way) on the hull without joining the deck as on fore deck. At least this is my intention! So I’ll start again, first starting from one simple deck to make it more simple. Then I have to see, once closed the transom, whether I can delete the actual deck, go back to again by extruding the quarter sheer line to build up quarter deck with its bulwark?! :unsure:
I think I have first (it should work) to model the transom with the simple curved surface or a half cylinder which work almost in the same way.
Oh… it will not take long to write a book on this transom issue!
At least we contribute to keep the forum alive!
Cheers 🙂
Adriano

Attachments:

• newintersection.JPG

[adriano natalini]

Hi

Well, I am trying the simplest way but still cannot understand why the system doesn’t work all the way through?
Have 3 layers: hull, quarter deck and transom on
Got perfectly curved surface well intersecting both hull and deck!
Now have problem in trimming eccess of both hull and curved surface :angry:
I’ve tried several ways but it’s messing around!
I’ve to mention that when intersecting layers I’ve to do this twice i.e. Hull+Transom (this works only up to the sheer line only!) and deck+transom to get new control points on deck. may be this’s a normal procedure?!
Anyhow do you know in which order and which tools should I use now to get rid of both eccesses?
I would be very thankful sothat I could then go to next stage finally!
Adriano 🙂

Attachments:

• trimmingtransomeccess.JPG

[John R. Coil]

It sounds right that you’ve got to find intersections twice since you’ve two layers (hull and deck).

What I’ve found in my own experience is that when you intersect with multiple layers like this (I’ve usually got multiple layers too) is that near the transitions between layers the program does not necessarily create all the control edges you may need on some layers. I would guess that this is because some CPs which may have been used to help create subsequent faces in a different layer (like a deck fit to a hull) are co-joined to the later face but are actually a part of the earlier. For example, “Move” your deck up a foot (which you can always undo) and you’ll possibly find it assuming a humped shape as the CPs that are really part of the hull remain where they were but the control edges between them and the deck also remain. While I’ve not qualified the program’s behavior exactly it seems that it will miss putting that last control edge into the “newer” face in a different layer that connects to the CP in the “older” face in the original layer. The CP needed is usually there, though, as it was inserted as part of finding the intersection between layers for that layer.

So before I start deleting excess I find it necessary to create these missing control edges — their presence stops the program from deleting more than I want it to.

Sometimes you can have one of these missing control edges that is really small because of where you were intersecting layers — say if your curved surface passed very close to, but not exactly through, one of your CPs on the sheer line. If you find you’ve a problem area that wants to delete too much zoom up on the problem area after you undo the delete and see if there isn’t a missing tiny control edge to deal with first.

I hope that helps.

[adriano natalini]

Thanks again for yr prompt help.
Am always afraid you loose yr patient any time and in that case I would be almost lost!
Anyway it looks like am now on the right “path”, got finally the transom eccess trimmed off and the desired nicely curved transom shape.
Apparently there was a new control point which I extra inserted at the end of the sheer line in order to model a rounded up joint sheer/transom/ deck top line ruther than a corner one. I may have to deal with it later after I got the transom in place!
So now if I put on all 6 control points of curved rurface and go for delete, everything disappears back to the original empity transom area?!
May be I am not doing it correctly?
Do you have any suggestions here too?
Many thanks in advance
Adriano 🙂

Attachments:

• trimmingtransomeccess.JPG

[John R. Coil]

Even IF you had been pesty — and you haven’t been — I’m not likely to loose patience: I take care of both my grandmother (who’s getting surly with age) and a handicapped sister (who’s a twerp).

The “problem” is likely that there aren’t enough corresponding CPs in the curved surface to leave behind a transom.

At this point I’d suggest either ditching the curved surface and create a new face for the transom from the existing CPs on your hull and deck. It will have the basic curved shape you want. Since you’ve probably got a 3rd control edge on this curved surface look to see if any CPs were inserted along it when you did a layer intersection with the hull and deck. If so — and there aren’t corresponding CPs on the hull/deck (you will need to move the curved surface to check), write down those values and manually insert them on the hull/deck before you form any new face … that way you can better replicate the control edge(s) that helped to define to shape of the transom’s curve.

The alternative would be to manually create a matching set of CPs to the hull/deck in the curved surface. Which wouldn’t necessarily be hard (just start by dividing your interior edges and moving the new CPs around to match) — if you do this it may be easier to move that layer a set distance away from the rest of the model so you don’t have problems selecting the wrong CPs on the hull/deck rather than your transom.

The advantage of the former is ease.

Turn on the option to see interior edges, if it isn’t already on, and see if any sort of criss cross pattern of lines has developed on your new transom. If one has AND you can also see it when your view is set to the render mode(s) (if not, don’t worry about it) you will need to break the transom’s control face up by connecting some of your CPs with control edges. Since the transom’s surface was defined with a vertical surface curved in the horizontal plane it is probably best if any control edges you add are as near up and down as you can get. These will break up the face and prevent some, if not all, of the criss cross effect (assuming any was visible).

[adriano natalini]

Thanks for all very well detailed infomations as usual!
Great respect for all the job you’re doing and feel sorry for yr handicapped sister!

Just one small thing before going back deeply into the matter:
to get rid of the left over curved surface is it correct what I am doing?
i.e. just put on those external surface control points and click on delete. Right?
Thanks
Adriano

[John R. Coil]

Yep.

[adriano natalini]

sorry, by the way, just realized that this morning I added by mistake the wrong (old)picture!
I attatch hereto 2 screenshots to show the stage I am right now. May be it’s better for you to understand or may be it doesn’t change yr opinion!
Thanks
Adriano

Attachments:

• transomeccesstrimming.JPG
• newshapedtransom.JPG

[adriano natalini]

Hi
Moving apart the curved surface I can see that no control points were inserted on it when intersencion hull/transom was done. So I suppose something went wrong ?!
This might be the main reason? 🙁
By the way I cannot see also any sort of criss cross pattern on it.
Thanks for any further opinion.
Adriano 🙂

Attachments:

• nocontrolpointsinsertedoncurvedsurface.bmp

[John R. Coil]

At this point I’d recommend just adding a new face where the transom goes to the model rather than try to trim the curved surface down. The hole you’ve created has the same curvature anyway.

It looks nice. Be sure to post it in show me your ships when you’re done.

[Hrvoje]

Adriano, how do you plan to remove unnecessary part of the cylinder surface? Can you do this at all?

Kind regards, Hrvoje

[adriano natalini]

Thanks
I’ll be glad to do that once……. I’ve got her right! It might take some time!
Also It depends how far with DS we can go into fine details since it’s matter of a modern classic type, at least this would be my target.
Hope I can get back to you inbetween for sure I’ll not lack questions.
Anyhow many thanks sofar.
Adriano 🙂

[adriano natalini]

Hi Dida,

Actually this is one of the few things which is pretty simple (as many other, but need to know first how!)
Once you have the cylinder in place you can trimm off any part of it, just put on its control points
all around portion you want get rid and click on delete. (at least it worked like this with me)
My last few screenshots are showing just what I left over from the cylinder (half) which looks exactely as a curved surface and which you can model it endless in the same way. Very useful tool but in my case I’m facing problems somehow in intersecting it…..
Glad if I can help
Adriano

[Marven]

Please have a look at the following video tutorial
Hopefully it will explain the whole process to you better…..

[adriano natalini]

Thanks a lot
Adriano

[adriano natalini]

Hi There,
is anybody able to help how to master “subdivide control net”?

f.e. I would like to model small details in a particular spot without adding any control points on a face but (most probabily only way) having to subdivide the control net in a way to not interfer by subdivision other parts of the boat.
Is anybody there who has any experiences on this?
Many thanks in advance
Adriano

[Hrvoje]

Hi Adriano!
I can tell you what I do, but I am not sure if this way is the best.

1. Split the edges in the area of interest.
2. Move new points to the desired position.
3. Connect points with edges.
4. Let smaller surfaces to live within 4 new points!

You can, in this way, subdivide the area in question in smaller parts and adjust the form of the ship.
If you find the other way, please, let me know what you did. 🙂

Have a nice day!

Kind regards, Hrvoje

[adriano natalini]

Thanks Dida,
It sounds it will work.
Let’s see how far it’s suitable to what I have in mind.
I’ll let you know.
Adriano 🙂

[adriano natalini]

Hi Dida,
May be you can help in this (simple?)case.
I’m trying to get the sheer line curved at the joint sheer line/transom boundery edge which will become joint of transom/sheer line/deck
What I would like to achieve is to let run the bulwark over the transom on a curve over the hull
avoiding that sharp corner which normally we get. I should mention that the free board has a tumble home shape. So it would be no problem to extend the bulwark out on the hull
I tried several ways starting also from closed deck, but this brings other problems, inserting simply control points would be easy but of course get nearby frames distorted!
You mentioned earlier to build a new face but how in this case, I tried but got only a mess!
Attatched a screen shot of my model, plan view, without transom and deck.
My question is, is there any simple way to make a curve on a boundery edge without interfering other hull parts?
thanks for any suggestions
Adriano

[adriano natalini]

Hi Dida
here is the screen shot
Adriano

Attachments:

• insertcurveinthesheerline.JPG

[Hrvoje]

Hi Adriano!

I will make a new ship and try to solve the problem on it. As soon as I get something I will let you know.

Kind regards, Hrvoje

[Hrvoje]

Hi Adriano! (Again!)
I have made transom following Marven’s video, but first I did the deck. On the picture you can see what I got.

Then I did transom together with the deck and the hull.

Is that what you wanted?

Kind regards, Hrvoje

[adriano natalini]

Thanks Dida
It’s not matter of transom at all, I managed that as well.
I am attatching a picture to show you what I would like to do i.e. modeling a curved bulwark’s joint
at sheer line/transom area to avoid a corner joint.
A picture can better explain.
Adriano

Attachments:

• the-friendship-40-5384_1b.jpg

[Hrvoje]

Is that what you want?

If “yes”, than switch of crease edge on certain part of sheer line.

Kind regards, Hrvoje

[adriano natalini]

Thanks Dida for yr attention to the matter,
I think I have enough curved aft hull wall (tumble home) pls look at it from the plan view as shown from the attatched picture. I simply want run the sheer line in a curved shape when joining the transom top on which I’ll be extruding bulwark and deck Sofar I’ve a corner joint which I want chance. So I believe I have to fix this before closing transom and deck. Thanks
Adriano

Attachments:

• curvedbulwark.bmp

[Hrvoje]

Hello, Adriano!

First, let us check if I get the problem! 🙂 🙂
Is this close to the solution?

If I am on the right way we can continue the discussion. Your problem is very interesting.

Kind regards, Hrvoje

[adriano natalini]

That’s it ! Dida
Perfect! that’s what I am looking for! An old classic design!
It looks like I have to close deck and Transom first right?
If you do not mind pls let me know other details.
Thousend thanks
Adriano

[Hrvoje]

Hi, Adriano!
I am glad that we found the solution. Now, I would need the program to make video for you. Do you have any idea what program is using Marven to make his videos?
Yes I closed transom and the deck first. I will make some screen shots for you, but I did not preserve step by step versions of my yaht. So I must start from the beguining and take screen shots of progress.
Have a nice day! 🙂

Kind regards, Hrvoje

[adriano natalini]

Am very glad that you’re so kind to help! (unfortunately at moment therearen’t many around the forum)
Well..a video would be too nice, no idea how DS operates it, Martijn or Marven could answer the question anyhow they check every post! (I suppose)
There is WMP program, Windows Media Player but you need to be very fast and remain under 5 mts. time but it can be a hassle! do not worry I would be happy just with yr description starting with deck and transom in place?! it shouldn’t take that long.
Thanks
Adriano 🙂

[Marven]

We use Camtasia for our videos. If you’re looking for a free solution try Camstudio

[Hrvoje]

Thank you Marven, I will use free Camstudio, but not for this occasion. I suppose that Adriano has not time to wait until I learn how to use it.

Kind regards, Hrvoje

[Hrvoje]

Hi, Adriano!

Here is description of the procedure I used to create the hull. Probably, this is just one of many possibilities.
This is starting situation:

Then we will move to the deck. Make other layers invisible. Subdivide edges using “Edge split” tool. New points will be the edge of the new deck shape. Later you will remove unnecessary” control point with “Point collapse” tool.

Connect control points with new edges. Make these edges crease.

Edges which where crease switch of, they do not to be crease any more.

Kind regards, Hrvoje

[Hrvoje]

Now we have following situation on the transom:

Two existing points we will connect with an edge:

And make this edge crease.

Also define non crease edges on the transom as crease edges. In the previous steps I made them non crease, I was not careful enough. :blush:

One part of the deck let’s move to the layer of the hull.

And this is what we have as the result:

Now when you see what we get, you can try to make the deck shape better. Also you can improve the shape of the hull.
I hope it helped.

Have a nice day Adriano. 🙂

Kind regards, Hrvoje

[adriano natalini]

Thanks a lot Dida for all yr efforts!,
It’s little late now to work on it, I’ll do it tomorrow.
Have good night.
Adriano 🙂

[adriano natalini]

Good morning Dida,
Thanks I managed it without problem it’s basically very simple (but need to know how!) The “Crease” tool is all about!
I’ll have after that to delete the deck to go back to the( new )sheerline to build up bulwark and deck back again.
Anyhow finally I got that nice old style! Thank you.

By the way, am facing some problems getting a smooth transom surface, indeed my transom is far from that (allmost) square shaped one Martijn is showing in the video, mine is prettycurved in all X-Y-Z axis and consequently have problem in filling back the missing portions when creating new face while in “interior edge” mode. The result is that I get that kind of “cris-cross” net mostly around the transom rand (this not having all the way down the needed 4 c/points to create a new face!) :angry:
I’ll try few more times and if the problem persists I may ask for help again?!
Adriano 🙂

[Hrvoje]

Good morning Adriano!

I am glad that you are proceeding with your project. Of course, I will help you if the problem will not be above my possibilities. I am still in the learning phase, discovering possibilities of the DelftSHIP.
Will you make the ship when you finish this project?

Have a nice day! 🙂

Kind regards, Hrvoje

[adriano natalini]

Hi Dida,
Well, as you may assume, am at learning stage as well, on the 60s and retired at least officially! Sailing has been my entire life’s passion and now I would like to design my (dream) sail yacht (14 mt. definitely classic style but with modern technology) according to my pratical experience and taste. Building her is on the wish list but whether it will happen it depends upon some factors. Anyhow even to see my dreamboat on paper , at the end of the day, it would be also a nice personal satisfaction.
If you wish to correspond on ruther personal matters you can contact me any time through my
e.mail: np.design@usa.net however I would be pleased .
Thanks
Adriano

[Hrvoje]

… The result is that I get that kind of “cris-cross” net mostly around the transom rand (this not having all the way down the needed 4 c/points to create a new face!) :angry:
Adriano 🙂

When we need 4 points and 4 edges to define new face let’s try to fool the program 😛

I just added one point to have 4 of them. If this can be the solution in your case, try it. 😉

Kind regards, Hrvoje

[adriano natalini]

Thanks Dida
I’ve to restart again from the beginning something is going wrong
It’s a kind of pain! I need a couple of days to relax and get back to it.
I’ll keep you updated.
Thanks
Adriano 🙂

[Hrvoje]

Hi, Adriano!

After you delete selected faces the edges will become “boundary” edges. 🙂

Kind regards, Hrvoje

[adriano natalini]

Thanks Dida,
Good to know that! 🙂 🙂
Have good day
Adriano

[Hrvoje]

Hi Adriano!

Here is the window corner. There is possibility to reduce number of edges and connect the window frame into one piece.

First insert the face to close the gap between frame parts.

Then delete selected edge.

Then select the unnecessary edge and collapse it.

Select unnecessary point and collapse it.

To this with all four edges.

Kind regards, Hrvoje

[Hrvoje]

After we close the gaps in all four edges we will have the gap between the window frame and the glass. (Window is not mosquito-proof. 🙂 )
It is possible to close this gap around the glass using the same technique as for the window corners.

Kind regards, Hrvoje

[Hrvoje]

Together wit the doghouse, seen from the profile:

Kind regards, Hrvoje

[adriano natalini]

Many thanks Dida,
It worked out very well!
..and appreciate your continuos and valuable contribution to the forum.
Have a nice day 🙂
Adriano

[adriano natalini]

Hi Rurudyne,

May be you have a solution to my followings question marks?!

A – I found out that the sail area data shown on the hydrostatic design report by far is not correct
what do we have to do to get the correct sail area?

B- to locate the Center of Effort is there any system available on DS?
Appreciate any help.
Rgds
Adriano/Italy

I am about to locate the center of effort do you know the way how to get it on DS

[Hrvoje]

…
A – I found out that the sail area data shown on the hydrostatic design report by far is not correct
what do we have to do to get the correct sail area?
…

Adriano, is the sail area two times bigger than you expected?

Kind regards, Hrvoje

[John Owles]

Dida,

Do you have ‘Symetric’ checked in the Layers table? If so, uncheck and you should have the correct sail area.
Hope this helps.

[adriano natalini]

Hi Dida,

The data from the hydrostatic report shows far more than double the real sail area?!

-sails are designed perfectly on the central line
-to tick or untick the symmetric box doesn’t show any changes indeed this tool is not working with the “sail” at least in my case?!

– meanwhile I got the way (thanks to Mike) how to compute the Center of effort 🙂

By putting all sails, or the ones you want involve, on one layer you have the VCG and LCG sothat we can easily locate the CE of the sails.

Unfortunately the sail area shown on the hydrostatic report still gives a wrong measurement?! :angry:
rgds
adriano 🙂

[Marven]

Sail area in the hydrostatics report? Do you mean the lateral area perhaps?

[adriano natalini]

Hi Marven, glad to hear from you again.

Well… I mean the layer properties within the “Design Hydrostatic report” which is also showing the the square area .
I assume mainly it’s matter of symmetric but I cannot find the tool to disactivate it?!
Strangewise the one box next to (my) sail layer properties is not working?!
Thanks for any tip 🙂
Adriano

[John Owles]

Hi Dida, Adriano et al,

I made each sail its own layer with ‘Symetric’ unchecked (second check box, to the right of ‘Visible’. The areas I obtained in design Hydrstatics seemed reasonable and with ‘Symetrics’ check they doubled.

I exported the Lines Plan as DXF file and used Turbo Cad to check the areas – they came out the same. I also drew the sail plan up by hand in the old fashioned way and the areas were the same.

The boat is now in build and the sail plan is with my sailmaker. It seems to work for me and I can’t really see anything else to suggest.

What sort of sail configuration are you planning? This current project has a Lugsail and Jib.

All the best
JayOh

[adriano natalini]

Hi Jayoh,
Thanks for yr comments.
I was hoping to get some feed back from Marven to find out why Symmetric check box in my case is not reacting at all.
I may miss something in the setting?!
The rig in question is Gaff sloop with approx. something over 100 sq mt sail area and the data shown by the systhem seems to me to be even 4 times the real one????!!!
Do you have any idea what could be wrong?
Thanks
Adriano 🙂

Attachments:

• Gaffsloop.JPG

[John Owles]

Hi Adriano,
In my Layers window, anything directly part of the hull is automatically symetrical and cannot be checked and made asymetrical. Other items brought into the design via create box, cylinder or keel/rudder wizard etc., can be checked as asymetrical.

How did you create your sails? Did you bring the in using Create Box, with the ‘Create New Layer’ checked or use a different method?

One other thing that I noticed. If you ultimately want an accurate sail area, I would remove control net from within the sails, leaving them with just the outline, as per a traditional sail plan.

I have a little spreadsheet routine to calculate CE over LCR, which I use outside DS
as a check.

When I get a moment I’ll have another look around and if I see something else I’ll let you know.
JayOh

[adriano natalini]

HI Jayoh
I simply created the sails adding new control points and new face.
This could be the reason why the symmetric box is not activeted, as you say only parts started from cylinder, box or keel etc. have this option.
Anyhow just find out that the sails had two interior edges!!?? do not know why so by deleting one the sail area is reduced by 50%. Still need to go down another 50%
By removing the contol net also nothing has changed.
Thanks
Adriano

[John Owles]

Hi Adriano,
I think you have the answer. I use a box created as a new layer, knock it down to a flat square and create the sail from that. The Symmetry check box works and your areas should be correct.

Good luck
JayOh

[adriano natalini]

Yes Jayoh,
It looks like that the starting base makes that difference!
My concern now is: anything modeled by inserting new control points and faces will have double sq. area?! It can be a big headache for me to go back and check it!!
It would be good to have some words from the administrator this regarding.
Have a nice day
Adriano

[Author]

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