Maxsurf

Andrew

I didn't say that Maxsurf doesn't have powerfull and robust suface generation, I am sure it does.

I also referred to MAxsurf as " a good and thorough package " so don't take too much umbrage. I agree it is a good precision modeling package. Thats why I want to export Rhino generated models to it

My point is that Rhino's surface generation is more comprehensive considerably easier to use and review a conceptual design than it is in Maxsurf, and that an easy import transition from a trimmed surface model from Rhino to Maxsurf would be a very nice feature ....surely you can concede that ?



In reply to ErikG

Erik

Try designing some good looking easy built chined hulls.......

Cheers

 

Mike

Since you are talking about hard chined hulls, what is so great about developable surface hard chine hulls in Rhino? I see the following limitations -

1. Developable surfaces are lofted between two 3D curves, so no interactive updates of ruling lines as you modify the edge curves.

2. The lofted developable surfaces are polygonal, not NURBS surfaces, so limited precision available for downstream applications

3. Primitive handling of developable surface runouts, linear surface ends only

4. No ability to blend developable portions of surface with non developable portions (i.e. developable aft sections of hull topsides with non-developable flare forward)

5. Changes to edge curves require relofting of surface.

In short, Rhino's developable surface options are not particularly refined. Maybe OK for doing small plywood or aluminium dinghies, but not that great for serious work.

 

I have to say that as a maxsurf/hydromax/prefit/rhino user I do agree with some of mike's arguements.

The Maxsurf suite is a very powerful program for use with NEW designs where it's precison and fair surfaces are a pleasure to work with. Unfortunately, its ability to accept accurate models of existing vessels within a reasonable time frame is less than it could be.

A general purpose cad program such as rhino has far more tools for creating nurbs surfaces than maxsurf. This gives flexibility and ultimately speeds up the modeling process for an existing shape. Smooth import of trimmed surfaces to maxsurf is then desirable. (surfaces trimmed with curves are not supported...) Dynamic trimming is not needed in this case.

I think that in some ways maxsurf has ignored a very large part of its potential market by requireing the use of a nurbs model in its hydromax program. A user imput offsets option(which the program now creates anyway) as an alternative to opening the nurbs file would make things far more functional. Probably 90% of all stability work is carried out on existing vessels which is something Formation could cash in on.

My 2 cents.
Brett

 

Brett

I agree entirely. We intend to modify Maxsurf 's import function soon so that it can read static trimmed models. We have also done a lot of work to allow Hydromax to read wireframe or offset based models, should be available relatively soon.

Andrew

 

Andrew

My remark about chines was replying to Erik's Q as to why you would want to import trimmed surfaces. It wasn't meant to be seized upon as a debating point.
Interestingly we have one large sailing vessels designed solely with Rhino using entirely developable surfaces, it weighs 36 tonnes and the design process was flawless. But then we are engineers..................

I state again that Rhino's surface generation is more comprehensive considerably easier to use and review a conceptual design than it is in Maxsurf.

It is very good that an easy import transition from a trimmed surface model from Rhino to Maxsurf is forthcoming.

I look foreward to it, keep up the good work.

 

Andrew,

I constructed a multi chine boat in maxsurf, used a flat surface as stern and then trimmed shell and stern.
To have the surfaces developped I opened the design in workshop, but that did not recognize the trimmed surfaces?
I only got the whole plate and not the trimmed stern? What did I do wrong?

 

Dutch Peter

Rather than turning on trimming, turn on intersection lines and define the plate to the intersection line that you used for the trimming. For best results make sure that you do this at Highest Precision to make sure that the intersection is calculated as accurately as possible.

All other parts in Workshop (frames, stiffeners, decks etc.) should be defined with trimming turned on.

regards

Andrew

 

Andrew,

Must be doing something wrong? Doesn't seam to work. Can Workshop(version 2.16) handle more then 4 contours, as I'm selecting 6! See attached picture of the selected contours. When selecting just 4, I have the option of choosing the 'add plate'-option, but then I get the notification that all contours must lay in the same surface.

 

You are restricted to 4 contours only at the moment, and from the same surface (i.e. plates cannot extend accross a surface boundary). This limit is actually only a user interface restriction at the moment, the actual development algorithm is able to handle n-sided plates no problem, so we will be relaxing this restriction in the near future.

How come you are using such an old version of Workshop? It will be very primitive compared to recent versions.

 

Andrew,

It's an inheritance from my time at Tech College. I fiddle around with it as a hobby.