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Steve.M  
#1 Posted : Sunday, July 13, 2008 8:22:30 AM(UTC)
Steve.M

Rank: Senior Member

Joined: 6/18/2008(UTC)
Posts: 978

Was thanked: 1 time(s) in 1 post(s)
Hello,

Due to the problems with the surface G1/G2 (reported here http://forum.punchcad.com/showthread.php?t=1263) I have been building from curves. I have been finding some problems, so have again gone back to basics.

On the xy plane I drew 2 splines at tangent leaving a gap so the "join" would then, as the user guide states
Quote:
Join Curve:
The join Curve tool is used to smoothly join 2 curves. Joining of the curves will create a single curvature continuous curve from the original curves
The results do not show that.

As the example:-
Pic 1: 2 spline tangent curves
Pic 2: The join made
Pic 3/4: Curvature check showing bad curvature

Pic 5: Curve Blend/join made and checked in Rhino

Regards,

- Steve
Steve.M attached the following image(s):
01.jpg (5kb) downloaded 5 time(s).
02.jpg (6kb) downloaded 5 time(s).
03.jpg (14kb) downloaded 5 time(s).
04.jpg (14kb) downloaded 5 time(s).
05.jpg (14kb) downloaded 5 time(s).

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unique  
#2 Posted : Monday, July 14, 2008 1:13:53 AM(UTC)
unique

Rank: Senior Member

Joined: 6/24/2008(UTC)
Posts: 591

Hi Steve,

Hmmm Yeah that is strange....I hadn't come across that yet because I have been sketching degree 1 curves thus far and that combination provides G0 results. However, something is wrong with this command - Tim ??

A more appropriate cmd might be 'smooth fill curve' otherwise known as a blend curve...this can found in the fillet/chamfer palette.
Steve.M  
#3 Posted : Monday, July 14, 2008 3:59:59 AM(UTC)
Steve.M

Rank: Senior Member

Joined: 6/18/2008(UTC)
Posts: 978

Was thanked: 1 time(s) in 1 post(s)
Hi Paul,

unique wrote:
A more appropriate cmd might be 'smooth fill curve' otherwise known as a blend curve...this can found in the fillet/chamfer palette.


In 2d space the "smooth fill curve" does appear to be better than the join, but go into 3d space and the "smooth fill curve" gives some very strange results, I was leaving those examples/questions until some feedback from the developers on the already opened questions I have.
unique  
#4 Posted : Monday, July 14, 2008 5:17:52 AM(UTC)
unique

Rank: Senior Member

Joined: 6/24/2008(UTC)
Posts: 591

:D ohhhh dear I see what you mean.

The smooth blend in the file attached is how it should look ?
File Attachment(s):
3d Blends.zip (2kb) downloaded 6 time(s).

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Steve.M  
#5 Posted : Monday, July 14, 2008 5:46:16 AM(UTC)
Steve.M

Rank: Senior Member

Joined: 6/18/2008(UTC)
Posts: 978

Was thanked: 1 time(s) in 1 post(s)
Hi Paul,

unique wrote:
The smooth blend in the file attached is how it should look ?
Which attached file? (edit: you added the file as I was posting: I will look later)

Those I attached to the first post are showing the "Join" which should be giving correct curvature.

The "Smooth fill curve",.. I am not yet completely sure what it is doing,.. it looks like some extension to the original lines to an interception point, then a blend is made from the new end points,.. which is not what is expected/wanted.

I have attached 2 pics showing 2 curves (both on different planes,.. but the planes are at 90)

Pic "Rhino" shows a blend in Rhino, which then does give me a number of options (G1/G2 etc) and results expected
Pic "Shark" is the result of a "Smooth fill curve" with no additional option given, and not expected/wanted

I did attempt a "Join" between the curves in Shark,, but there was no good curvature.
Steve.M attached the following image(s):
Rhino.jpg (61kb) downloaded 5 time(s).
Shark.jpg (33kb) downloaded 5 time(s).

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