Orca3d- are lines actually fair?

[George Bulterman]

In Orca3d, when using hull assistant, by clicking "create hull", are the resulting lines truly fair enough to loft and build on?

 

[TANSL]

You should do some checking for the traditional system. The programs for renderings, in many occasions, are prepared to soften and disguise existing irregularities presenting a very smooth aspect although, perhaps in reality, it is not sufficiently smooth for the necessary precision in the constructive drawings.
If there is a tool that allows you to visualize the normal vectors on the surface, they can also help you to check the smoothness of the shapes. Any lack of regularity in the normals indicates that there exists a point or a conflict zone.

 

[pafurijaz]

In Orca3d, when using hull assistant, by clicking "create hull", are the resulting lines truly fair enough to loft and build on?

Yes the generated lines are corrected.

The tools are there to help build the hull shape you want quickly and easily. That hull can be as simple as you like, or as complex as necessary and the final geometry will not only look nice on the screen but can be readily analyzed to assure that it is both ‘fair’ and buildable.

 

[TANSL]

I again recommend that you make checks on your own or that you ask for feedback from users. Logically the software manufacturer will defend that their software is wonderful. The subject is serious enough, the risks and the expenses to which you are exposed are very high and you should not adopt a solution (not only I speak of orca3d, but of any other) without being totally sure of its excellence.

 

[DCockey]

The programs for renderings, in many occasions, are prepared to soften and disguise existing irregularities presenting a very smooth aspect although, perhaps in reality, it is not sufficiently smooth for the necessary precision in the constructive drawings.

What is the connection between Orca3D and rendering?

 

[TANSL]

What appears on your screen when you visualize a surface?. Maybe I'm wrong but I call that a render or rendering.

 

[DCockey]

Based on my experimentation with Orca3D and my knowledge of how NURBS surfaces work, I'll say that the surfaces from the Orca3d "hull assistants" are inherently fair. The developable surface hull assistant surfaces can have lines of tangential but not curvature continuity. The sailboat hull assistant surfaces have a singularity with the isocurves at the forefoot which can cause difficulties when creating offset surfaces and similar. However both of these practices appear to be common in boat design.

Whether you can create a shape using the hull assistant input which is close enough to the shape you want is a different question. The sailboat hull assistant in particular is limited in the shapes it can create compared to the range of shapes commonly used for sailboat hulls.

 

[TANSL]

I do not want to harm anyone but, based on what you say, I would not be very sure if I could apply that system to the generation of the construction drawings of the hull and the structure.
I'm sorry to say but the constructive drawings of the hull are too serious a thing to do without sufficient guarantees. I think the best thing is for the OP to look for examples of ships built with this system and draw their conclusions according to the experiences of other users of the system, if any.
I have nothing against Orca3D. I would think the same about any other system not sufficiently contrasted by practice.

 

[DCockey]

Let's repeat the original question:

In Orca3d, when using hull assistant, by clicking "create hull", are the resulting lines truly fair enough to loft and build on?

It's about a method for generating a math version of a hull outer surface. Nothing at all about "the generation of the construction drawings of the hull and the structure."

For those who are not familar with Orca3D information about it is available at Orca3D Naval Architecture Software | Marine Design Plug-in for Rhino https://orca3d.com/ Note that there is nothing about structure or construction drawings.

Added: It may also be useful to point out that Orca3D is intended for the design of craft which would usually be considered boats, not ships.

 

[Ad Hoc]

In addition to David's reply above...

You, the user, still need to check how fair the lines are and what you will do with the output. If you merely wish to make a simple model out of wood, is very different from the degree of accuracy you will need for a set of Lines to build a hull - production faired Lines. Thus, your output objective will dictate how much scrutiny and checks you will need to apply to the model.

First checks are to take off lines in different views/planes and see how they look in the other views.

Erecting dianagals for example int eh body plan, or buttocks - the shape that you desire will be shown to be smooth or not so smooth. Since the Maths behind it (as per David's posting above) will create a set of Lines, but the Maths does not know what you will do with it. Thus is the final surface that has been created fair and developable, for your end purpose. Only knowledge and experience of the hull form and its objective will tell you that...i.e do not reply on the programme to give you a perfectly fair hull, the final tweaking must come from the user!

 

[DSR]

I would definitely agree with TANSL and Ad Hoc, I used a couple different programs to develop and render my project, but I still caught minor errors in the data points that had to be corrected, when I lofted the hull full-size, to generate truly fair lines.

 

[DCockey]

I used a couple different programs to develop and render my project, but I still caught minor errors in the data points that had to be corrected, when I lofted the hull full-size, to generate truly fair lines.

What software did you use? How did you obtain the "data points"?

 

[TANSL]

lines truly fair enough to loft and build on?

I suppose, and I hope not being very wrong, that when the OP says this it is because he wants to build the ship with the information, or from the information generated by Orca3D.

Nothing at all about "the generation of the construction drawings of the hull and the structure."

If, as I have previously assumed, you want to build the ship, it will probably be necessary to generate the construction drawings of the hull and the structure.
Let's suppose that the division between boat and ship is in the 16 m length (to give a figure). It is very likely that an aluminum boat of that length needs a collection of construction plans as complex as those of a ship of 100 m in length. And I do not think I'm wrong again because I speak from my real experience obtained working on boats and ships.
Based on my experimentation and my knowledge of how NURBS surfaces work I can assure you that the NURBS are nothing magical (NURBS are something very difficult to control) and, therefore, they do not assure us that there are no discrepancies between the input data and the results they obtain. When one needs to do a rigorous job, it is not advisable to accept, without checking, what comes out of the computer, even if they are NURBS surfaces. But, as I say, everything depends on the commitment to quality that each one wants to assume.

 

[DCockey]

TANSL, what type of "input data" are you assuming the Orca3D Hull Assistant uses - a set of line or something else?

 

[TANSL]

@DCockey With the expression "input data" I refer to the data or actions that the user must provide for the program to do its work. Happy?
I wonder if my English is so bad that you do not understand anything I say. In addition to analyzing my expressions in depth, you could give the OP information, examples, based on your experience with Orca3D, with the NURBS, with the "boats", so that he can draw conclusions about what he is worried about.