Is there an "all in one" software package?

Hi, I'm a boatbuilder looking to get into the yacht design field. I have no experience with CAD, only manual drafting skills. I am trying to decide which CAD programs are the best to train up in????

Can anyone recommend one software package that can be used all the way from hull design right through to performance analysis and 3D modeling with photo realistic imaging? If not, what combination of software would best suit these needs?

Thanks Michael

 

No, is the simple answer... but there are packages that fit into a neatly modular system better than others.

Your performance analysis is an interesting requirement. Do you mean VPP or resistance estimates based on empirical methods or on CFD?

For Empirical resistance estimates, I don't know of a CAD package that copes with it internally, but it is not too hard to get enough data out. For CFD I'm now working with Rhino (Version 3) to build surfaces, then use my own systems to produce the grid, then importing the answer into Rhino to see what's going on.

I assume you'll need a stability capability as well. There are packages (or add-ons) that will cope with it, but I haven't been particularly impressed with them.

In terms of a general yacht design program to do all this, I am in the process of writing one. The preview release (source on demand) is available from my website but is only for the Risc-OS platform. The Linux/Mac (and I dare say someone will compile it under windows) will have an alpha release for the end of the summer (around september).

The site is www.MarineDesign.tk

Cheers,

Tim B.

 

Thanks Tim B for your reply. I'm a novice in this field so some of your terms aren't familiar to me i.e. VPP and CFD. What are these? I had a look at your website and can see that I have much to learn. Given that I'm at the entry level of CAD Yacht Design can you recomend an appropriate CAD package, and one that won't limit me as I gain more knowledge. I noticed you used Rhino, would you recomend this, or your own hull design program?

Thanks again
Michael Harris

 

VPP is a Velocity Predicition Polar, generally based on an empirical model.

CFD is Computational Fluid Dynamics, and at a very basic level it is a way of working out forces on the hull due to the water.

My hull design program may be considered to be work in progress. It will do some of what is required, but I really need time to work on it. As I said, I use Rhino for the entire design (after (and sometimes including)) the basic hull design. I have found it to be the most intuitive CAD package around, as have several of my freinds who have used it. A lot of people in the marine world use MaxSurf. There is nothing wrong with this, but it was not intuitive for me (and only 3 surfaces in the academic version? get real!!!). All I can suggest is to look around and use every free trial available.

For free trials I have a rule. If I'm still struggling to get a hull-form after an hour it's not a good system. A vicious rule, but it weeds out the rubbish pretty quickly.

Cheers,

Tim B.

 

Thats the sort of advice I was after. I'll give some of those free downloads a go. Much appreciated, and thanks again.

regards
Michael Harris

 

Well, there is one...

With the exception of photo realistic rendering (though rendering is possible) you have the option of going for NAPA (www.napa.fi). Whilst the possibilities of the suite are virtually unlimited, the problems may be twofold:
It requieres a high amount of training (you will be down to coding to use this tool)
It is somewhat expensive (you will end up spending at least several $10k for the most basic licenses)

However, the most advanced and serious designers only use NAPA.

Regards

Z

 

yea right, catia can do it, seasolution, tribon, albacore research, defcar, they all offer solutions and they are great, but the price IMO is too much, even for small to medium boatyards or designers, and the most serious designers uses anything that works, no NAPA only, besides for less cost it is possible to achieve what you achieved with NAPA or other software's, is it more convenience to use a full integrated solution?, maybe, IMO no, because rhino with it's plug ins will cover more of the tasks for design and production for small boats (...small boats...), but again it all depends what your using it for and what size of boats or ships you participate more, designing or production.

 

Michael,

There is such a wide variety of software and tasks covered by computers that there is no real simple answer. However, I will tell you what I have done.

The first thing you have to realize is that all software packages are merely tools, and they cost money, so you want to get the most capability of those tools for the least amount of money. Even with my relatively simple set-up, I find I am overpowered compared to many boatbuilders who do not even have computers.

For merely drafting, all you really need is a drafting package. AutoCad is the most popular one, and you can get a simplified version for about US$500 that is compatible with the most expensive version (about US$2,500 when I bought the full AutoCad 2000). With AutoCad, or some similar drafting software, you can create drawings to your liking, and print them out on different sizes of paper, from letter size to long rolls. For any drafting software that you buy, make sure it can read drawings in .dxf format, which is a generic drafting format. AutoCad produces drawings in its own .dwg format, but also .dxf so that the drawings can be read by other software programs.

I find increasingly that I print to tabloid size (11" x 17") because these prints are easy to read and can be printed on a desk top printer. If you want to print larger, then you have to go to a plotter. If you want a plotter, buy an inkjet plotter from Hewlett Packard--they're the best. I have an E-size color HP 750 Plus color plotter that actually is underused, but I can print large prints and Mylar patterns at full scale when necessary.

That's just the drafting and printing. If you want to actually design boats, you need a 3-D software package, and there are two types: surface modellers and solids modellers. Most are surface modellers (ProSurf, Fastyacht, MacSurf, AutoShip, etc.) Many come with abbreviated start-up packages that are not too expensive, usually under US$500. I use ProSurf, which does not have all the usual Windows version bells and whistles (it still uses some DOS programming) but I am used to it, and it is relatively easy to use. You have to have some hand-holding no matter which program you get, because you have to understand what the computer can do to create surfaces, and cannot do, and you have to take those into account as you design the boat.

I also like ProSurf because it has built-in hydrostatics and stability calculations that are important when designing a boat. Some of the other packages, like Rhino, do not have very good built-in hydro/stability capability, if any at all.

A stand-alone Hydro/Stability program is GHS which has a very good following and is very common.

The one program that is gaining popularity is Solidworks because it can create shapes out of solids and then create architectural drawings from the solids model. It is a very sophisticated program, maybe too sophisticated. I found it was almost too interconnected between solids modelling and drafting that I considered it not appropriate for my work, particularly with my skill and experience with 3-D surfaces and AutoCad--I saw no reason to change design philosophy at this point in my career.

With a surface modeller, you create the appropriate hull, deck, appendage surfaces as you need them. Then you take "cuts" through the model, saved in .dxf format, to read into the drafting software. That is, the most difficult part of drawing a boat is to get the hull shape accurate and with the right hydrostatics and stability. You still have to create construction drawings, and you start with the "cuts" that you get from the surface model. Say you need to draw a midship section: get the "cut" from the surface model, bring it into AutoCad, and fill in the details within AutoCad. This is what I do. Once in AutoCad, you can create detail to your heart's content, copy it to any scale, and copy/cut/paste details from one drawing to another. Then you can print to any type of printer or plotter.

As I work with other designers, we almost all use AutoCad, or can at least trade drawings through the internet in .dxf format.

For other engineering and design, we use other software packages and use our own skills to determine the nitty gritty details. ProSurf has a reasonable VPP, but others may be able to recommend a better VPP. For powering and propellers, I use NavCad, an expensive but powerful program for determining hull resistance and powering/propeller sizes for all manner of boats and ships. For small engineering problems, I may use an Excel spreadsheet that I can program for the problems I want to solve. I also do a lot of hand calculation because they are fast and simple.

I have also found Rhino to be a good translation tool for 3-D surfaces. Most surface modelling programs can export to an .igs file (which is required for 3-D modelling) but I have found that the different 3-D software packages have real trouble reading some other packages .igs files. But if you can export via .igs to Rhino, then clean up the Rhino image before you send it, many other people also have Rhino and can then read the file OK. From Rhino, they can then export to their own 3-D surface modeller if they don't want to stay within Rhino. So I have found Rhino to be a good translation tool.

I am less experienced with rendering in Rhino, for which it is very good. But I have also found there is little need for rendering in Rhino among my clients. It is too expensive to charge off the cost of pretty rendering because it takes so much time to create good renderings--clients are not willing to pay for the labor for pretty pictures. Just give me the details, thank you very much, and let's get to building. However, others may differ, and you certainly see lots of pretty rendered boats. But I in my business, we usually start with owner's sketches which we translate directly into AutoCad drawings and the 3-D surface model. The rendering only comes later, and we are too close to the final drawings that we don't need the renderings. It depends on the designer and his business.

That's the perspective from here in Florida.

Regards,

Eric

 

Good to hear a full description of the software packages and general method. I have to say that I use Rhino's rendering capability more for hull-fairing (Rhino 3 - use rendered viewports) but it is sometimes useful to visualise something quickly, and once you're used to it, it's really pretty quick.

What I have decided to do is a basic hydrostatic code to plug onto either Rhino, or LMH (my code) I will post it on my website in the near future. (next few weeks I hope)

Incidentally, I don't think much of AutoCAD, except for line-styles. I do all the detail in Rhino, treating it as 3D, using a new file and different layers instead of line-styles, then take it to an ACORN RISC-PC as WMF, use WMF->Draw. Then use ACORN's !Draw. it is not as transportable, but !Draw is much nicer to finish the drawing with.

Tim B.

 

My apologies, I have just got !Draw to output Postscript files. looks like this might be a nice method.

Cheers,

Tim B.

 

You should try Rhinomarine hydrostatics. I found it "a very good hydro/stability" plug-in. If you like, it can make a very complete hydrostatics report to Excel with many plots.

Terho

 

Rhino-marine.... I thought it was appalling, but never mind. It may have been improved since I tried it, but having just done the theory, I know exactly how it was calculating initial stability. given the hull-form you can get the full hydrostats, not just the initial stability.

Tim B.

 

Could this solve your problems of line-styles in Rhino?

http://www.voidoid.com/lino/index.htm

Terho

 

Yeah, LINO would do it either, I just happen to have a RISC-PC sitting on my desk, so I use that.

Tim B.