Rhnio3d and DELFTShip

[Chris Reynolds]

I’m new to DelftShip and I use rhino3d quite often. Since I can’t seem to create a boat hull in DS that would be a hard chined hull such as would be made from plywood I was trying to figure out how to combine the modeling capabilities of rhino3d with the analysis abilities of DS. Anyone have any suggestions on how to best get my hull model into DS from Rhino?

Or am I just missing something in DS. I have yet to figure out how to create a hull with flat planking instead of the rounded hull shapes.

Chris

[Chris Reynolds]

Seems it was only a matter of changing the edge from rounded to creased.

Chris

[MICHAEL KERR]

Hi Chris,
go to Download–>Tutorials–>Reproducing and existing linesplan, in the tut they use a planing hull as an example, there is a lot of other useful info about DS for you. I use DS to create my hulls and Rhino to finish them off, I have imported bits an pieces designed with Rhino back into DS but it was a long time ago and I cant remember what file format I used, except to say it is possible.

[Jim]

You cna export as a 3D dxf file which rhino will read in.
To go the other way from Rhino into DS you need to save as an IGES which DS will import if I am not mistaken.

[Chris Reynolds]

Thank you for the response. I’ll give that a try. I’ve read the manual now and I spent last night playing around with the program and trying a few things to see how they work. I really like the program and I’d like to use it more often.

Chris

[Ian Scales]

Import to Rhino3D from DelftShip/FreeShip (DS/FS) is problematic. Presently, nothing works very well.

IGES works if the hull curvature is simple but if the hull has complex curves (as e.g. in historical ships), then IGES breaks the surface into a number of parts which when imported to Rhino cannot be fitted back together smoothly: the result is lumpy even after a rebuild. This is a pity, because with the exception of this really fatal problem, IGES delivers a surface that is easily editable in Rhino.

3D-DXF and OBJ export options both create a mesh. This is difficult to use in Rhino3D because most of Rhino’s commands deal with curves and surfaces. The mesh can be converted by Rhino into a NURBS polysurface, but this doesn’t help much, because it also has limited editability.

Moving on, STL produces a mesh with all faces divided diagonally, quite useless in Rhino. Lastly, Dxf polylines can be used to loft an editable new hull surface in Rhino, but it won’t be the same shape as the hull made in DS/FS: all your work of fairing in DS/FS is likely to be wasted.

The Rhino developers have made open source the library for reading and writing Rhino.3dm directly; this could freely be used in DelftShip if Martijn would decide to incorporate it. Until then, the relationship between Rhino3D and DelftShip is very crippled. This is a shame, because read/write in 3dm would make DelftShip very popular as a lower-cost and possibly more powerful alternative to the Orca3D plug-in for Rhino.

[Chris Reynolds]

yeah I’ve noticed that about trying to use the two programs together.

Chris

[otaku]

For me, Rhino has too many commands for me to concentrate on learning and drawing. I design my hulls in DS and then export them as DXF 3Dpls and DXF 3d mesh. I import them into Punch! ViaCAD Pro, though i started in March 08 with ViaCAD 2D/3D. Pro has a number of additional surfacing and solids cutting/trimming tools that make like a bit easier for me.

VC 2D/3D as a demo is free to use. IIRC, Pro can be downloaded as a demo, too. As to the wish that DS would use the open source Rhino code, i wish that there was a two-way conduit between ViaCAD Pro and DS. VCP is (in my mind) vastly easier to use than AutoCAD, which is why i don’t use AC nor Rhino. Since the licenses are owned by my employer and i cannot afford to have my hobby wrecked by expensive software i won’t pirate, VCP (at ~$250) was a no-brainer for me. Granted, ViaCAD has not hydros tools. However, the surfacing tools and solids tools work fairly well for me. If you have the time, check it out. It has more of a Mac look and feel than a windows/ACAD/Rhino l&F, but i like the reduced screen clutter.

[Chris Reynolds]

I can definitely understand the reluctance to learn a new design package. I’ve been using Rhino since it was version 1.0 and so that’s what I prefer to use.

[MICHAEL KERR]

Dxf polylines can be used to loft an editable new hull surface in Rhino, but it won’t be the same shape as the hull made in DS/FS: all your work of fairing in DS/FS is likely to be wasted.
Hi Stringybark, I agreee with most of what you said but could you give us some examples to support your above statement. I use DXF polylines to import into Rhino and I have noticed a difference in fairing between both programs as well. But the conclusion I came too was that the fairing routine in DelftShip was aimed more towards merchant shipping while the fairing routine in Rhino is for engineering. So the routine in Rhino needs a greater degree of accuracy and if your prudent you can use this difference to your advantage.
But overall I agree with your conclusion, that when it comes to accuracy it would be better from our point of view and DelftShips to directly import and export in the default Rhino format.

I would also point out that in Maxsurf Workshop you can directly import 3dm files from Rhino.

On BoatDesign.net Rhino it is the most popular hull design software according to there poll.

And YDS (Yacht Design school) which has over 400 students on its books uses and recommends Rhino to its students.

But Rhino has one major flaw, it doest start off with a default hull shape, while DelftShip does.

So Rhino has the numbers and Delftship has the price.

So go for it Marven, today the Netherlands tomorrow the world. Ha HA Ha Ha cough cough cough mmmm hairball.

[Chris Reynolds]

If Freeship is the open source version of DelftShip, I’m surprised no one has added in a rhino import/export option.

Chris

[MICHAEL KERR]

They would have if they could have got Rhino for free.

[Chris Reynolds]

what a friend of mine did when he was working on the rhino export for his airfoil analysis program was he worked with the developer info which I believe he go online from their site, and then had me test it out for him since I was an avid user of rhino.

Chris

[MICHAEL KERR]

Well if thats the case Chris, Marven can do the coding, you can do the beta testing and Ill make us waffles.

[Marven]

stringybark wrote:

IGES works if the hull curvature is simple but if the hull has complex curves (as e.g. in historical ships), then IGES breaks the surface into a number of parts

It has nothing to do with curvature, you’ll need to maintain a regular controlnet: all faces should be made out of 4 points, and each internal point should be connected to 4 faces. Only regular surfaces like this can be converted to a single NURBS surface. Since NURBS surface cannot handle 3 or 5 side surfaces these parts should be converted into smaller 4 sided surfaces.

[joop dresscher]

geez guy’s where did you learn that wisdom 😉 i will try igis export as said here again, with hopefully some better results, thanks ahead

DS polylines exported to 3D acrobat pro extended (not free eighter and with a nasty net connection when overstaying the month free trial) gave good looking results

into rhino or 3dmax i havent found a way to handle those polylines yet but wonder if from the in 3D pro extended acrobat included toolkit *.U3D files are to import / translate into a workable model?

keep me posted! [file name=polylines.pdf size=139051]http://www.delftship.net/delftship/media/kunena/attachments/legacy/files/polylines.pdf[/file]

Attachments:

• polylines.pdf

[Miquel Borillo]

Hi all,

I’m new into this forum.
I’ve been using Rhino.4 3d for a while now in ship designing, specially traditionals sailing vessels.

My experience with Rhino shows me, as some here have posted, it’s very acurate, it’s excellent coming to generate all kind of curves but about hull surfaces it can be probematic when coming into odd ends, as for exemple a clipper bow or aft. The “extend and trim” technique is sometimes the only solution I’ve found so far for such cases.

I think really it’s a versatile software which files can be exported in many otherCAD or hydrostatics softwares, and as you know has plug-in like Rhinomarine or it’s successor Orca 3D

The main obstacle I’ve found so far by using Rhino in producing hull shapes is the lack of a proper autofairing function able for ship’s hull design demands. That makes the fairing of a new and complex curved hull an extremely demanding task in hours as well as in patience.

Reading the performances offered in DSpro publicity
and its affordable price, I wonder if it’s way to go.

I wonder if a Rhino generated surface or a set of curves fron the same procendence can be used with DSpro for generating a new surface and autofair it
And if in general DSpro can be considered a reliable shorcut for designing hull forms from scratch and which hydrostatics programs are compatible with it.

Thanks in advance and excuse my english as I’m not a native speaker.

Miquel

[Ian Scales]

I have not had time to explore the limits of IGES export to Rhino3D in view of what Marven has said about IGES requirement of 4-sided control nets. I would point out though that even the default hull surface in DS, that is generated for a ‘New’ project, will be found to have split into two surfaces when imported to Rhino via IGES. Since that is about the simplest hull surface you could get in DS, that doesn’t bode well for IGES as a satisfactory file export medium. And as noted earlier, the other DS export options either produce a hard mesh that can’t be easily edited, or 2D curves that when lofted result in a much different surface from that originally made in DS.

Export as 3DM (Rhino format) would probably solve these problems. Until – if ever – DS has this option, none of the advantages of Rhino can be used. These include Rhino’s relatively low cost, strong forum support, wide capability, large range of aftermarket products including CAM and high-end rendering, all of which result in Rhino’s huge popularity. That DS is locked out of this wider world by lack of inclusion of 3DM is a great pity, since DS has very powerful features – indeed it seems to be even better than Orca3D in many respects.

So how about it Marven – the need for 3DM export has come up time and again over recent years in various forums. Nothing has happened. Does this mean that DS development is unlikely to ever include Rhino support? If so, then I would like to know; because then I should drop DelftShip, buy Orca3D and move on. If models made in DS can’t be migrated, its really not worthwhile persisting with it. As I say, that would be a pity but unfortunately that’s the reality.

What I don’t understand though, is why this relatively simple enhancement – 3DM export – can’t be incorporated, no doubt to the profit of the DS developers: DS sales would surely increase quite dramatically. So what’s the problem? Is it technical? Animosity-related? No time? Or what?

[Marven]

It’s a technical matter. Delftship uses a different type of surface than Rhino does, and this has advantages as well as disadvantages. One of the disadvantages is that the surface has to be converted to NURBS surfaces, the type of surface Rhino uses. Due to the fact that Delftship allows for triangular and other faces which are not supported by any NURBS modeler the converted model can have multiple surfaces. Once the delftship surface is converted it can be send to any NURBS modeler. Rather than implementing the 3DM format the choise was made to stick to IGES because it can be imported into multiple programs, rather than implementing and maintaining several file formats.

[otaku]

HI Marven!

I just found out that i am crazy for using exported IGES surfaces from DS Pro and importing into Punch ViaCAD Professional.

However, I found that although the DXF 3D Mesh export from Delftship preserves the color and layer names information, the DS Pro export to IGES doesn’t seem to. Is it the flavor, or is IGES too limited?

What is NICE about the IGES surface is that i found i have numerous panels i can to manipulate in the surface such as coloration and layer on/off once the model is in ViaCAD Pro.

But, if i want colors and layer names retained, i have to use the DXF 3D Mesh. The problem with the DXF 3D Mesh is that i cannot thicken those meshes into solids. I have to reduce them to first to surfaces, which produces a bazillion little matrices which i then have to “join”, a tedious and time-consuming endeavour.

I imported the DXF 3D Polylines, the DXF 3D Mesh, and the IGES surfaces and tried to manipulate layers on and off to pick and apply colors, but it is too time-consuming.

So, Marven, is this something you are able to facilitate, or is it a limitation of IGES, or should i try other settings again?

Thanks!

[Marven]

Color is supported in IGES as well (see image below).
It is send as a separate entity along with each surface. Rhino supports this perfectly. Perhaps Viacad doesn’t?

Attachments:

• Image3.jpg

[otaku]

Oops. (I meant to say “crazy about” (excited/ecstatic), not “crazy for” (stupid/nuts/silly), hehehehe.

I think I succedes before in simply changing the color in ViaCAD, but it certainly doesn’t seem to import colors that I assigned in Delftship. For example, my hull is broken down into some 16 compartments/zones, and I color-code each one to help me know where in the model I am. I’ll check with VC’s devs to ask.

Thanks!

[Author]

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