Welding Question - Polyloop

eezydo · 2nd March 2007, 04:58

Hello,

I'm totaly new to Amapi and just messing around with the demo of 7.5 .
As a CAD-Guy I'm mostly interrested in NURBS Surfaces.
This is my Question : The Manual tells me that the Weld-tool can compute a single surface to replace a number of connected surfaces.
I tried this on a surface objekt consisting of 16 four-sided subsurfaces and I
couldnt make it work.
The catch is : this surface-objekt was derived through catmull-clarck smoothing of a simple mesh. Is it possible that this funktion doesnt work on
catmull-clarck-smoothed surfaces ? - or am I just doing something wrong ?

I Really want to know !!

eezydo

Thomas · 2nd March 2007, 09:53

can you post a screencapture of your scene before the welding?

eezydo · 2nd March 2007, 10:44

Oops!! - never have attached anything to a post.
-- Do I uploaed with "my photos" or via "manage attachments" ?
-- well I'll just try .

and thanks for the fast reply !

eezydo

edit : surface after and before smoothing.
-- no it's not a female torso -- happened by accident

Thomas · 2nd March 2007, 11:05

The manual explain this feature for two nurbs surface to create one. In your sample, you use polygonal surfaces and not NURBS surfaces

eezydo · 2nd March 2007, 12:21

Hi Thomas,
The smoothing was done via NURBS-smoothing ! -thus resulting in a NURBS-Objekt. - The scene-info tells me this and I have veryfied by exporting
IGES and STEP, which both give me real surfaces. Unfortunately with bad curvature near joining edges. - Thats why I had the idea ....
(Of course I know this is asking a bit too much.)
But I may have had a principle missunderstanding:
I guess That the Catmull-Clarck Objekt allthough made up of multiple surfaces,
is considered a single Objekt. Which is probably why, in Welding-mode ,the
" weld objekts" button is not active - so theres nothing to weld.
- I've tried tricking around it by reimporting an open nurbs -File.
Then I get to pick all the surfaces as single Objekts. - That does enable me to weld (veryfied by sceneinfo) but not to create a single surface.
Single surface -option on or off has the same result: Welding yes, but single surface no.
For CAD-Guys this would have been incredible. - As you probably know a lot of people are trying to find a closer link between Conceptual mesh-work and subsequent CAD -construktion. (Think of PTC's "Pro Concepts" and "ISDX" or CATIA's "Imagine and shape" -- but who the hell can afford them

).
Nevertheless I think Amapi is very usefull ! - So maybe with my next spare Euro's ......

eezydo

Thomas · 2nd March 2007, 17:20

If the curvature is your problem, their is a trick (thanks to Olivier Drion ;)
Apply a level one catmull clark smoothing on your polygonal object and collapse the Dynamic Geometry. Then, apply a NURBS smoothing.
The result will be heavier, but you won't have anymore the curvature problem.

eezydo · 5th March 2007, 14:11

Thanks Thomas and Olivier !

I tried this out and it works nicely. this is very usefull - I love it.

2nd March 2007, 04:58	#1 (permalink)
eezydo Vertex Join Date: Feb 2007 Posts: 4	Welding Question Hello, I'm totaly new to Amapi and just messing around with the demo of 7.5 . As a CAD-Guy I'm mostly interrested in NURBS Surfaces. This is my Question : The Manual tells me that the Weld-tool can compute a single surface to replace a number of connected surfaces. I tried this on a surface objekt consisting of 16 four-sided subsurfaces and I couldnt make it work. The catch is : this surface-objekt was derived through catmull-clarck smoothing of a simple mesh. Is it possible that this funktion doesnt work on catmull-clarck-smoothed surfaces ? - or am I just doing something wrong ? I Really want to know !! eezydo Last edited by Pete Exxtreme; 2nd March 2007 at 08:55.

2nd March 2007, 09:53	#2 (permalink)
Thomas Always learning new stuff Join Date: Jul 2002 Location: Merignac, France Posts: 11,319	can you post a screencapture of your scene before the welding? __________________ Polyloop owner & Administrator - no support by PM or email. Polyloop [EN/FR] - Meuuh [FR +16 ans] - Totyo [FR] - Pixologic [JOB] - Le ZBlog [JOB] - La3dpourlesnuls [FR]

2nd March 2007, 11:05	#4 (permalink)
Thomas Always learning new stuff Join Date: Jul 2002 Location: Merignac, France Posts: 11,319	The manual explain this feature for two nurbs surface to create one. In your sample, you use polygonal surfaces and not NURBS surfaces __________________ Polyloop owner & Administrator - no support by PM or email. Polyloop [EN/FR] - Meuuh [FR +16 ans] - Totyo [FR] - Pixologic [JOB] - Le ZBlog [JOB] - La3dpourlesnuls [FR]

2nd March 2007, 12:21	#5 (permalink)
eezydo Vertex Join Date: Feb 2007 Posts: 4	Hi Thomas, The smoothing was done via NURBS-smoothing ! -thus resulting in a NURBS-Objekt. - The scene-info tells me this and I have veryfied by exporting IGES and STEP, which both give me real surfaces. Unfortunately with bad curvature near joining edges. - Thats why I had the idea .... (Of course I know this is asking a bit too much.) But I may have had a principle missunderstanding: I guess That the Catmull-Clarck Objekt allthough made up of multiple surfaces, is considered a single Objekt. Which is probably why, in Welding-mode ,the " weld objekts" button is not active - so theres nothing to weld. - I've tried tricking around it by reimporting an open nurbs -File. Then I get to pick all the surfaces as single Objekts. - That does enable me to weld (veryfied by sceneinfo) but not to create a single surface. Single surface -option on or off has the same result: Welding yes, but single surface no. For CAD-Guys this would have been incredible. - As you probably know a lot of people are trying to find a closer link between Conceptual mesh-work and subsequent CAD -construktion. (Think of PTC's "Pro Concepts" and "ISDX" or CATIA's "Imagine and shape" -- but who the hell can afford them). Nevertheless I think Amapi is very usefull ! - So maybe with my next spare Euro's ...... eezydo

2nd March 2007, 17:20	#6 (permalink)
Thomas Always learning new stuff Join Date: Jul 2002 Location: Merignac, France Posts: 11,319	If the curvature is your problem, their is a trick (thanks to Olivier Drion ;) Apply a level one catmull clark smoothing on your polygonal object and collapse the Dynamic Geometry. Then, apply a NURBS smoothing. The result will be heavier, but you won't have anymore the curvature problem. __________________ Polyloop owner & Administrator - no support by PM or email. Polyloop [EN/FR] - Meuuh [FR +16 ans] - Totyo [FR] - Pixologic [JOB] - Le ZBlog [JOB] - La3dpourlesnuls [FR]

2nd March 2007, 10:44	#3 (permalink)
eezydo Vertex Join Date: Feb 2007 Posts: 4	Oops!! - never have attached anything to a post. -- Do I uploaed with "my photos" or via "manage attachments" ? -- well I'll just try . and thanks for the fast reply ! eezydo edit : surface after and before smoothing. -- no it's not a female torso -- happened by accident

5th March 2007, 14:11	#7 (permalink)
eezydo Vertex Join Date: Feb 2007 Posts: 4	Thanks Thomas and Olivier ! I tried this out and it works nicely. this is very usefull - I love it.

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