Offset surface with errors

[Felsentreu]

Hi,
I have a small problem with the function “Offset surface”.
Some points have different values. A new point at the stern deletes the mark of the corner point.
See attachment.

Greetings

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[Terrance Egolf]

Welcome to the wonderful, exciting—and unpredictable—world of the Offset Surface!

I don’t pretend to understand the mathematics underlying DELFTship’s surface modeling engine. However, I have attempted to do the same operation on a similar hull as well as some experimenting and the results were less than spectacular or expected.

Any location in your model’s surface where there is a fairly significant change or discontinuity in the orientation of the surface normals, you can expect some unusual behavior of this feature. For example, I have found that along the centerline of the model (y = 0), the new offset points will tend to wrap across the centerline in the –y-direction, as if the engine is trying to accommodate the average direction of the surface normals at this discontinuity.

Elsewhere, if you have crease edges intersecting at corners , or in close proximity to each other, the resulting offset surface can be really bizarre.

Here is my example that I faced in my brigantine model. This shows the moulded hull and transom. The transom is on a separate layer.

Next, I turned off the transom so I can just offset the hull surface by 3 inches/0.25 feet (sorry, I’m in the US).

Then I offset the selected surface (I don’t think it’s necessary to actually select the surface; the dialog has you offset the selected layer.):

So you can see the nasty details where the rail line converges on the transom.

All I can tell you is that after offsetting the surface, you should expect that you will need to do some cleaning up especially around edges that change direction or shape.

Terry

PS: The program puts the offset surface in the layer at the top of your layers list for some reason, so if it doesn’t appear after commanding the offset, then look in that layer, especially if it’s turned off.

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[Maarten]

Interesting.. Offset surface is not a feature that we use often, but it seems quite unpredictable indeed.

I hope we can find the time to look at what happens, and why, and maybe include a fix in the next release..

[Felsentreu]

Hi,
@Terrance wrote:

Welcome to the wonderful, exciting—and unpredictable—world of the Offset Surface!

Thanks for the welcome!

PS: The program puts the offset surface in the layer at the top of your layers list for some reason, so if it doesn’t appear after commanding the offset, then look in that layer, especially if it’s turned off.

Good hint, I was looking for a way to put the surface on a new layer.

@Maarten

Interesting.. Offset surface is not a feature that we use often, but it seems quite unpredictable indeed.

I think this feature is probably mostly used by your fan community of model makers.

Greetings

[john truelove]

Sorry guys, this is off topic but I cannot find a relevant topic and I am getting desperate.

I am taking off construction drawings from  a delftship model using the “print” command in the lower rhs of the menu ribband, then entering the image into libredraw and adding text.  This worked well on a previous project, but now when I try to print a front view / port side only (say to give a traditional body plan: bow to the right, stern to the left) I get an error message “invalid enumerator” and the program freezes.  Crashout and start again.

This appears to be occurring only since I last updated the program.  Relevant circumstances are

1.  front view
2. wire frame (?)
3.  showing one side only

It may relate to the stations/waterlines/buttocks grid as entered by “intersections”.  Sometimes deleting these enables me to print, sometimes not.  Sometimes reloading the model appears to carry with it the error othertimes it does not.  The stations input seems the worst offender.

I have been able to proceed via prtsc>Paint.NET>LibreOffice Draw but it is a clumsy way of doing business

Can anyone tell me what “invalid enumerator” means and suggest a way ahead?  PLEASE!

Jaytee

 

 

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[Terrance Egolf]

Hi jaytee.

I just installed v. 14.20 (342) of the program and tried to duplicate your problem with my own project file. I got nothing unusual. (See the attached Print pdf.) The only difference between my situation and yours is that I have moved the midpoint of the model in Project Settings about 50 feet aft of the AP. I did this so I don’t have issues trying to move control points in the Front or Aft views, but I also only get one side of the hull in these views with Both Sides turned off.

It may be an issue with your .dbm file itself. I suggest you submit it to Maarten so he can evaluate it.

Terry

DELFTship-Front-view

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[Maarten]

Hi JayTee,

 

I can also not reproduce the error you are reporting. What version are you using?

Is it a structural problem? Does it happen in other projects?

[john truelove]

Thanks for replying Maarten.  As I have just responded to Terry , I am using version: 14.20 (341).

There is another update that I have yet to install, I have tried but (I think) got called away and forgot about it – I presume that would raise my version to 342.

 

John

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