logo
NOTICE:  This is the new PunchCAD forum. You should have received an email with your new password around August 27, 2014. If you did not, or would like it reset, simply use the Lost Password feature, and enter Answer as the security answer.
Welcome Guest! To enable all features please Login or Register.

Notification

Icon
Error

Options
Go to last post Go to first unread
PATRICK DRAKE  
#1 Posted : Thursday, January 15, 2009 4:40:45 PM(UTC)
PATRICK DRAKE

Rank: Junior Member

Joined: 12/18/2008(UTC)
Posts: 11

I was wondering if there was a better / faster way to skin these curves (layer geometry) than the way I did it. I tried several times to use the skin with guide option but, every time a non acceptable surface was made. Thanks for any advice......
Patrick
File Attachment(s):
DOME QUESTION.zip (188kb) downloaded 6 time(s).

You cannot view/download attachments. Try to login or register.
Tim Olson  
#2 Posted : Friday, January 16, 2009 2:41:36 PM(UTC)
Tim Olson

Rank: Senior Member

Joined: 2/2/2007(UTC)
Posts: 5,446
United States

Was thanked: 498 time(s) in 352 post(s)
Originally Posted by: PATRICK DRAKE Go to Quoted Post
I was wondering if there was a better / faster way to skin these curves (layer geometry) than the way I did it. I tried several times to use the skin with guide option but, every time a non acceptable surface was made. Thanks for any advice......
Patrick


Hi Patrick

You might want to also try the cover with guide curves. With this surface option, the guide curves can cross each other.

Regards

Tim
Tim Olson
IMSI Design/Encore
unique  
#3 Posted : Friday, January 16, 2009 6:27:07 PM(UTC)
unique

Rank: Senior Member

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

Originally Posted by: PATRICK DRAKE Go to Quoted Post
I was wondering if there was a better / faster way to skin these curves (layer geometry) than the way I did it. I tried several times to use the skin with guide option but, every time a non acceptable surface was made. Thanks for any advice......
Patrick


Hi Patrick,

I'll be honest, so far the surface tools in VC have confused me, I think this is more down to me lack of using them. I see your method works ok but rather a lengthy process. In Rhino this is called a Network surface and I used your 5 curves to create the surface attached (brought into VC) the surface took 10secs to make ;)

Im about to download Shark and start testing so I would be most interested to see if you can build it in the same way & speed as Rhino....someone kindly put up an avi?? :D
File Attachment(s):
Dome_ph.vc3 (100kb) downloaded 7 time(s).

You cannot view/download attachments. Try to login or register.
PATRICK DRAKE  
#4 Posted : Saturday, January 17, 2009 7:48:34 AM(UTC)
PATRICK DRAKE

Rank: Junior Member

Joined: 12/18/2008(UTC)
Posts: 11

Tim,
The cover with guides is not available in Viacad (that is what I have) - unless I am missing something? I looked at your advanced surfacing tutorial and it shows the cover with guides option but, you are using Shark.
Paul,
Rhino is what I use mostly and am aware that "curve network" surfaces these curves in a few seconds, however, although it takes a little bit longer "loose loft" makes a much better surface in Rhino. I am experimenting with Viacad because the solid modeling, filleting, shelling, and ability to edit curves without deleting or, scaling them seem much more powerful than what Rhino offers. So far though (one month) I am still using Rhino for most everything......
Patrick
Tim Olson  
#5 Posted : Saturday, January 17, 2009 3:04:45 PM(UTC)
Tim Olson

Rank: Senior Member

Joined: 2/2/2007(UTC)
Posts: 5,446
United States

Was thanked: 498 time(s) in 352 post(s)
Below is a quicktime movie showing the dome surface created using a couple of surface types.


Net Surface (ViaCAD 2D/3D +)
--Add a point entity to the top and duplicate one of the arc cross sections to close.

Skin with Guide (ViaCAD Pro +)
--Add a point entity to the the top

Cover with Guide (Shark +)
Note isolines, not a degenerative surface as other types.


http://www.csi-concepts.com/Demo/videos/dome.mov



Tim
Tim Olson
IMSI Design/Encore
unique  
#6 Posted : Saturday, January 17, 2009 4:15:11 PM(UTC)
unique

Rank: Senior Member

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

Originally Posted by: PATRICK DRAKE Go to Quoted Post

Paul,
Rhino is what I use mostly and am aware that "curve network" surfaces these curves in a few seconds, however, although it takes a little bit longer "loose loft" makes a much better surface in Rhino. I am experimenting with Viacad because the solid modeling, filleting, shelling, and ability to edit curves without deleting or, scaling them seem much more powerful than what Rhino offers. So far though (one month) I am still using Rhino for most everything......
Patrick


Nice to see another Rhino face around these parts;) You have come to the right place if you wish to take advantage of the solid tools within VC and the Shark...im here for that very seem reason..Ohhh and also for M.T.O.S to produce drawings etc. I use my Rhino4 with VC all the time and I intend to keep it that way.....although VC/Shark will do 75% of what we do soon :D

btw: The reason I called it a network surface in rhino was down to _NetworkSrf

Tim Olson wrote:
Below is a quicktime movie showing the dome surface created using a couple of surface types.


Thanks for the movie Tim !!
PATRICK DRAKE  
#7 Posted : Sunday, January 18, 2009 4:32:31 PM(UTC)
PATRICK DRAKE

Rank: Junior Member

Joined: 12/18/2008(UTC)
Posts: 11

Tim,
Thank you so much for the video - it really explains alot !!!
Patrick
zumer  
#8 Posted : Monday, January 19, 2009 8:11:40 PM(UTC)
zumer

Rank: Senior Member

Joined: 11/4/2007(UTC)
Posts: 515

Was thanked: 1 time(s) in 1 post(s)
Originally Posted by: Tim Olson Go to Quoted Post
Below is a quicktime movie showing the dome surface created using a couple of surface types.


Net Surface (ViaCAD 2D/3D +)
--Add a point entity to the top and duplicate one of the arc cross sections to close.

Skin with Guide (ViaCAD Pro +)
--Add a point entity to the the top

Cover with Guide (Shark +)
Note isolines, not a degenerative surface as other types.


http://www.csi-concepts.com/Demo/videos/dome.mov



Tim



Tim, what is your formal definition of a "degenerative" surface? I had a look at your CSi-Concepts advanced surfacing PDF, and it looks to me that it means that a number of u or v control points are coincident in space. Is it that simple? I don't know, and as a result it's somewhere between jargon and arcane invocation.

murray
Tim Olson  
#9 Posted : Monday, January 19, 2009 10:16:38 PM(UTC)
Tim Olson

Rank: Senior Member

Joined: 2/2/2007(UTC)
Posts: 5,446
United States

Was thanked: 498 time(s) in 352 post(s)
>>it looks to me that it means that a number of u or v control points are >>coincident in space. Is it that simple?

Yup that's it!


Tim
Tim Olson
IMSI Design/Encore
zumer  
#10 Posted : Monday, January 19, 2009 11:53:40 PM(UTC)
zumer

Rank: Senior Member

Joined: 11/4/2007(UTC)
Posts: 515

Was thanked: 1 time(s) in 1 post(s)
Why is that undesirable? Does zero separation make parametrisation of the surface irrational at the coincidence point? If that's the case, does the kernel choke and burp up the messages we see once in a while, or do you override with additional error handling?

murray
Steve.M  
#11 Posted : Tuesday, January 20, 2009 7:18:48 AM(UTC)
Steve.M

Rank: Senior Member

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

Was thanked: 1 time(s) in 1 post(s)
I also at first thought it was my lack of knowledge in the correct use of the surfacing tools, but the mov posted by Tim as shown I was using the tools correctly and it is just the output surfaces that are quite unexpected.

Looking at the examples:

Net surface. That produced a surface that was pinched at the join of the added curve pic 01 shows the surface in shark using zebra, the loss of tangency clearly shows.

Skin with guides: I currently have the shark demo version 5.5 build 823 for checking the surface tools, but cannot build the surface as shown. I am given an "Acis error" of "Net curves Intersections are not monotonic" (see pic 02)

Cover with Guide. The results where rather strange. Although the surface had continuity it was in ripples over the surface. I have attached a screen grab pic 03, but it does not really show how rippled the surface actually is.


I do use Rhino a lot for producing surfaces so ran a "surface from network of curves" and produced an acceptable result on first attempt, which I imported into shark for comparison. (pic 04)
Steve.M attached the following image(s):
01 net.jpg (45kb) downloaded 5 time(s).
02 net g.jpg (28kb) downloaded 5 time(s).
03 g cover.jpg (45kb) downloaded 5 time(s).
04 net surf rhino.jpg (50kb) downloaded 5 time(s).

You cannot view/download attachments. Try to login or register.
Tim Olson  
#12 Posted : Tuesday, January 20, 2009 8:40:33 AM(UTC)
Tim Olson

Rank: Senior Member

Joined: 2/2/2007(UTC)
Posts: 5,446
United States

Was thanked: 498 time(s) in 352 post(s)
"Net curves Intersections are not monotonic" (see pic 02)

Steve, I fixed this is recent build.

I'm not familiar with the Rhino network surface. Does it require you pick mxn curve network? Do you need to create a point?


Tim
Tim Olson
IMSI Design/Encore
Steve.M  
#13 Posted : Tuesday, January 20, 2009 9:47:58 AM(UTC)
Steve.M

Rank: Senior Member

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

Was thanked: 1 time(s) in 1 post(s)
Hi Tim.

Originally Posted by: Tim Olson Go to Quoted Post
"Net curves Intersections are not monotonic" (see pic 02)

Steve, I fixed this is recent build.
Nice one.

Tim Olson wrote:
I'm not familiar with the Rhino network surface. Does it require you pick mxn curve network?
By default Rhino will attempt to sort the curve order, it does work well most of the time, but sometimes Rhino will not be able to sort and will ask for manual input for the UxV curves.

Tim Olson wrote:
Do you need to create a point?
No, I joined the 2 open curves and split the closed curve into 4 for the network (see pic).

The splitting of the closed curve was what I was originally doing in VC/Shark when I first started using the surfacing tools for that kind of surface, but always got the error "Surface U and V are in the same or opposite direction"


Regards,

- Steve
Steve.M attached the following image(s):
rhino net.jpg (23kb) downloaded 6 time(s).

You cannot view/download attachments. Try to login or register.
Tim Olson  
#14 Posted : Wednesday, January 21, 2009 3:27:43 PM(UTC)
Tim Olson

Rank: Senior Member

Joined: 2/2/2007(UTC)
Posts: 5,446
United States

Was thanked: 498 time(s) in 352 post(s)
>>Net surface. That produced a surface that was pinched at the join of the >>added curve pic 01 shows the surface in shark using zebra, the loss of >>tangency clearly shows.

Yup, your right it sure does. I suspect this is because I used a point on the top and it does not have blend tangents for a point. The zebra looks good by the bottom curve, but the closer it gets to the point, loses tangency along the seam.

Tim
Tim Olson
IMSI Design/Encore
Steve.M  
#15 Posted : Friday, January 23, 2009 5:31:24 PM(UTC)
Steve.M

Rank: Senior Member

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

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

Originally Posted by: PATRICK DRAKE Go to Quoted Post
I was wondering if there was a better / faster way to skin these curves (layer geometry) than the way I did it. I tried several times to use the skin with guide option but, every time a non acceptable surface was made.


There is no "skin with guide" option in VC, so I am not sure as to what tool you where attempting to use. The surface you posted, did you produce that in VC? If so by which method. I have looked at this but have not been able to produce a single surface that I find acceptable. I can split the surface construction up into a quad and skin, which surprisingly, does give good results (certainly not a method I would attempt in Rhino), so I am interested in your comstruction method.

Regards,

- Steve
Steve.M  
#16 Posted : Friday, January 23, 2009 5:48:41 PM(UTC)
Steve.M

Rank: Senior Member

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

Was thanked: 1 time(s) in 1 post(s)
Originally Posted by: Tim Olson Go to Quoted Post
I suspect this is because I used a point on the top and it does not have blend tangents for a point.
I will admit that I have not had much success when adding a point for a surface construction, but simply thought it my lack of knowledge on its use.
Is this then just a case of how Acis works?

More study and much more playing with VC needed.

Regards,

- Steve
PATRICK DRAKE  
#17 Posted : Tuesday, October 13, 2009 7:42:31 PM(UTC)
PATRICK DRAKE

Rank: Junior Member

Joined: 12/18/2008(UTC)
Posts: 11

There is no "skin with guide" option in VC, so I am not sure as to what tool you where attempting to use. The surface you posted, did you produce that in VC? If so by which method. I have looked at this but have not been able to produce a single surface that I find acceptable. I can split the surface construction up into a quad and skin, which surprisingly, does give good results (certainly not a method I would attempt in Rhino), so I am interested in your comstruction method.

Regards,

- Steve


Steve,
sorry I took so long to respond to your question about how I constructed the skinned surface I posted. Yes I used ViaCad Pro to make it. I experimented first by drawing a 2 inch diameter circle and making a 1 inch arc to the top. Instead of using a rotational surface (which is easy) I knew I needed to use a skin to a point because of the dome shape. I needed to know how many cross sectional profiles I needed to make an accurate skin and then it dawned on me: change the 1 inch arc to an interpolated spine then turn on control points and put a circle at each control point level. It works perfectly but, in order to describe a half circle you need ten descending profiles - alot of work!! On the dome I took the largest arc and converted it into an interpolated spine and used its control point "levels" on all the other arcs. I scaled ellipses to fit the points and then skinned them. If you look at my original drawing on here and turn on all the layers you will see what I mean.....
Patrick
ZeroLengthCurve  
#18 Posted : Wednesday, October 14, 2009 11:03:33 AM(UTC)
ZeroLengthCurve

Rank: Senior Member

Joined: 5/15/2008(UTC)
Posts: 985

Thanks: 15 times
Was thanked: 31 time(s) in 22 post(s)
I am not at my laptop to try this, but would an alternate way of doing this be possible by intersecting solid spheres, then turning them to lines/surfaces? Before or after converting solid to surface, it might be possible to add iso lines or cutting planes or actual surfaces or shapes to use for cutting or dividing any lines/surfaces. This might get past the "unacceptable" or deformed surfacing...

Just a thought (and, maybe a bad one since i'm not at my laptop, but i wanted to get the thought out in case anyone faster than i can try it and comment on it or say it's not doable and end the thread i injected...)
Users browsing this topic
Guest
Forum Jump  
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.