TurboCAD Forums

The Ultimate Resource for TurboCAD Knowledge

Register
 
The purpose of these forums is to discuss TurboCAD.  Please keep the discussion of other products to compatibility issues or how the other software’s can be used with TurboCAD.


Lofting problem encountered, please help.
Read 3703 times
* September 15, 2015, 10:08:56 AM
Dear All

Please help to see how why I can't loft attached and how to fix this problem.
Thanks in advance.

ps. got the error of ACIS solid type is selfintersecting or invalide; null pointer to body given.

Best Regards
Simon

Logged
=================
Yuansheng Tsai
tsai.yuansheng@gmail.com

Windows 10 Pro
TurboCAD 2015 Professional 64-bit - Platinum Edition
Version: 22.2     Build: 90.0


* September 15, 2015, 10:21:38 AM
#1
I exploded the upper Polyline several times, until it was nothing but Lines and Arcs, then rejoined the pieces into a new Polyline. Lofted OK then.

Henry H

Logged


* September 15, 2015, 11:04:12 AM
#2
ps. got the error of ACIS solid type is selfintersecting or invalide; null pointer to body given.

Best Regards
Simon
[/quote]

There was something wrong with the top profile, I redrew it using the 2D Polyline tool and replaced the original. It then lofted fine.
Henry used an easier method. Polylines can be a bit tricky sometimes. If there is the slightest gap or overlap at the intersections it'll cause a problem.
« Last Edit: September 16, 2015, 05:09:48 AM by DonCW »

Logged
DonCW
2017 Pro with Light Works Plug in
2018 Platinum
2020 Platinum

Windows 10
There's so much to learn and not much time left to learn it.


* September 15, 2015, 11:21:55 AM
#3
got the error of ACIS solid type is selfintersecting or invalide; null pointer to body given.

Can I ask how you created them ?

There are double nodes - see attached, this can confuse TC not knowing where to start the loft (at least that's my theory), whilst it is best not to have double nodes, one way to reset is to select a node in edit mode and right click - choose break, then right click - choose close, do this on both polylines then it will probably loft, but personally I'd avoid double nodes.
« Last Edit: September 15, 2015, 11:26:28 AM by Andy H »

Logged


* September 15, 2015, 01:30:20 PM
#4
got the error of ACIS solid type is selfintersecting or invalide; null pointer to body given.

Can I ask how you created them ?

There are double nodes - see attached, this can confuse TC not knowing where to start the loft (at least that's my theory), whilst it is best not to have double nodes, one way to reset is to select a node in edit mode and right click - choose break, then right click - choose close, do this on both polylines then it will probably loft, but personally I'd avoid double nodes.

Hi Andy,

It's a new day with something new for me to learn, how did you find the double nodes?

Logged
DonCW
2017 Pro with Light Works Plug in
2018 Platinum
2020 Platinum

Windows 10
There's so much to learn and not much time left to learn it.


* September 15, 2015, 04:06:04 PM
#5
how did you find the double nodes?

Hi Don,  its just that I've seen it a few times on the forum over the years, fortunately there weren't many nodes, so I just grabbed each one and started to move it, then click cancel if the node was ok.

Logged


* September 15, 2015, 06:04:59 PM
#6
First of all, Thank you all.
With Henry's hint, I found that it is not really connected for the upper polyline.
Andy, I can't recall how the double nodes occurred, as I make it the same way as lower profile.
I could only think of when I trimmed the unwanted parts, I made some mistakes there.

My finding, with Henry's hint :) , is the same as Don's.
After exploded once, I use 'chain polyline', as attached, and found the disconnection.
After use 'meet 2 lines', then rejoin, it works.

I am not sure if it is a right way or any other better approaches to find the disconnection, but it works for me.
Any suggestion on finding disconnection (more efficient way) would be appreciated.

Thanks again, all.

Best Regards
Simon  , a happy user :)

Logged
=================
Yuansheng Tsai
tsai.yuansheng@gmail.com

Windows 10 Pro
TurboCAD 2015 Professional 64-bit - Platinum Edition
Version: 22.2     Build: 90.0


* September 15, 2015, 07:04:22 PM
#7
First of all, Thank you all.
With Henry's hint, I found that it is not really connected for the upper polyline.
Andy, I can't recall how the double nodes occurred, as I make it the same way as lower profile.
I could only think of when I trimmed the unwanted parts, I made some mistakes there.

My finding, with Henry's hint :) , is the same as Don's.
After exploded once, I use 'chain polyline', as attached, and found the disconnection.
After use 'meet 2 lines', then rejoin, it works.

I am not sure if it is a right way or any other better approaches to find the disconnection, but it works for me.
Any suggestion on finding disconnection (more efficient way) would be appreciated.

Thanks again, all.

Best Regards
Simon  , a happy user :)

The right way is the one that works ;-)

Henry H

Logged


September 17, 2015, 01:11:44 PM
#8
Hi Guys,

I am encountering a problem I have not met before.

I have a section of a boats hull which is part of the plans for a model contsructed using the sandwich method.

I have developed polylines for the top and bottom of this section which I offset and then loft.

The loft works fine in surface mode but will not loft in solid mode, nor will the resultant surface convert to solid so that is can be shelled.

Other sections loft in solid mode and can be shelled.

Thank you
Bob

Logged
TC 14 Deluxe, TC 19 Pro
Windows 7, 64bit 8GB Ram


* September 17, 2015, 02:01:30 PM
#9
Hi Guys,

I am encountering a problem I have not met before.

I have a section of a boats hull which is part of the plans for a model contsructed using the sandwich method.

I have developed polylines for the top and bottom of this section which I offset and then loft.

The loft works fine in surface mode but will not loft in solid mode, nor will the resultant surface convert to solid so that is can be shelled.

Other sections loft in solid mode and can be shelled.

Thank you
Bob

Please post the .tcw, Bob.

Henry H

Logged


September 18, 2015, 04:50:20 PM
#10
Hi Henry,

The tcw Nobby 1 is attached

Regards
Bob

Logged
TC 14 Deluxe, TC 19 Pro
Windows 7, 64bit 8GB Ram


* September 18, 2015, 05:04:35 PM
#11
Hi Henry,

The tcw Nobby 1 is attached

Regards
Bob

I don't see any polylines in that drawing, Bob, nor anything else that could serve as lofting profiles.

Henry H

Logged


September 18, 2015, 05:58:15 PM
#12
I am sorry,

The polylines have been removed. However if you look at the coloured sections aligned vertically to the keel you will note that one of them is a surface, namely No3 up from the bottom and the others are solids. The remainder have not been manipulated to change them from the imported stl file to tcw solids which is the aim of the exercise.

I have a habit of trying always to remove unnecessary items from the drawing, sometimes to my detriment. All the completed sections were derived using exactly the same parameters, i.e. 2 splines of a half section, mirrored then added to make a whole, offset by 0.75"and finally lofted as a solid.

I guess if the lack of drawing objects makes it impossible to provide any clues then I will start again from the stl import and see if the problem replicates.

Thank you
Bob

Logged
TC 14 Deluxe, TC 19 Pro
Windows 7, 64bit 8GB Ram