Rhino or TouchCAD?

[Raggi_Thor]

Originally Posted by Robert Miller

My wish list:

• Both of these packages need to support the use of diagonals in producing lines to allow complete hull lines drawings, using similar work flow as in traditional hand drafting....
Robert

Rhino can draw diagonals, look at the hull in front view or "body plan" and use the section command.

Rhino also works quite well with Alibre Design.

[Robert Miller]

"Rhino can draw diagonals, look at the hull in front view or "body plan" and use the section command."


Does this not result in buttocks lines... as the "section" command generates parallel lines, not diagonals? Am I correct?

Thanks.

Robert

[Raggi_Thor]

If you section vertically, yes, if you section horisontally you get waterlines, if you section diagonally you get, yes, diagonals.

[hydroptera]

"Rhino can draw diagonals, look at the hull in front view or "body plan" and use the section command."

Does this not result in buttocks lines... as the "section" command generates parallel lines, not diagonals? Am I correct?

Thanks.

Robert

Hi Robert:

No, buttock lines are vertically oriented sections that run fore and aft, or parallel to the centreline of the boat. Diagonals can be viewed as where a plane originating from the CL extends on an angle (down at an angle of 45º, for example) to the edge of the hull. When you measure along the plane to the point where the diagonal intercepts the hull, transfer that as a point from the CL in plan view, then join the points as a curve... you get a diagonal. They are useful for seeing how fair a boat is in the bow area (and stern if the boat's a double ender). Some see them as a way to approximate the travel of water molecules along a hull as the boat moves. I hardly use them any more as design software (TouchCAD and MaxSurf in my case) show unfairness as colours really well, and the waterlines and buttocks usually give me all I need.

LM

[CGN]

All you have to do is "orient" the direction and angle of the sections, and you can get any section (buttocks, diagonals, sections etc..) from your hull using TouchCad or Rhino

[Robert Miller]

Originally Posted by CGN

All you have to do is "orient" the direction and angle of the sections, and you can get any section (buttocks, diagonals, sections etc..) from your hull using TouchCad or Rhino

Actually, this precisely illustrates the point I was making when I said I wished both programs (and lots of others) would support diagonals.

The method you suggest, and also noted by others above, could result in drawing one diagonal line, only, at a time. The parallel lines you are working with must rotate and be adjusted to create each single diagonal (which are not usually parallel), which, by itself, is not that big a deal. It's what you do when drafting by hand anyway.

Once you have created the digonals to your satifaction with this method, it must then be flipped to cover the opposite side of the centerline in body plan. In plan view, however, the diagonals will have to again be manipulated to show their curvature opposite side of centerline to other hull lines, as we are used to seeing in traditional lines drawings... with perhaps the curve of section areas superimposed. All of this can be done, I agree, but it is a bit more manipulation than would be necessary if laying in diagonals were a built in function.

In that all of the above must be done manually, step be step, the constant and frequent adjustment of diagonals in fairing in the other lines is somewhat discouraged. That, precisely, is the capability I would like to see made a built in function.

The fact that these programs allow you to draw any line any place you wish, may indeed mean you can represent diagonals on your drawing, but that is not the same as supporting the use of diagonals as easily created, easily manipulated, easily changed lines ... where changes made immediately appear in all views, just as do sections or waterlines... and with changes made to one of these also represented in other lines affected by the change.

Robert

[Raggi_Thor]

You can easily make a script for this in Rhino, the script may be somethink like: Delete evrything on layer Diagonals, section the hull to make new diagonals, rotate the diagonals to put the in your desired plane, etc, etc.

[ludesign]

It is not all that difficult to do diagonals in TouchCAD either.

[Raggi_Thor]

I bet it's not difficult at all, Claes :-)