what is he doing?

[seagulls]

I understand some of it.But its really short on explaining some bits.Needs pictures i think.

[cheasie]

he has pictures on the bottom of the post

[seagulls]

I still dont get it! :D

[cheasie]

i don't get it either, but it seems like he made the surface for the car very easily

[tilite]

http://img159.imageshack.us/img159/4536/untitled1mx9.gif (http://imageshack.us)

So the whole idea with this is creating a few perimeter curves and making a basic surface. Then rebuilding that surface and tweaking it to be more accurate to what you are really searching for.

[F001] Frame one is simple I have just created a 4 seperate curves with 3 control points.
[F002] Here I have simple adjusted the median point or the seperacte curves along the verticle axis.
[F003] And a Patched Surface (untrimmed)
[F004] Use _extractisocurve to extract the selected curves here - these are determined soely by the patched surface. Create as many or little as you need.
[F005] Here I have trimmed the isocurves with the selected perimeter curves and deleted the surface.
[F006] Simply turned on the control points for the isocurves to show they need to be simplified.
[F007] Rebuilt the isocurves (_rebuild settings: 3,3 [NOTE] you will need more control points the more coplex your intended geometry is)
[F008] Patched a new surface with isocurves

[NOTE] My geometry hasn't changed from the original patch as I never adjusted the isocurves... so;

I did this wrong: I was in a rush and it was just an oversite

What you will want to do is only build isocurves in the U or V direction (not both like I did). Once you have rebuilt them adjust the control points to inform your new geometry. Then patch. The more contol points you have the more acurate and dense and tricky the process becomes so be careful.

I do apologise for doign that wrong but hopefully it is enough to start playing with the process so I wont redo it. However I can understand how you would be confused so if you want I can do that again... tell me what you think.

[EquiNOX]

Cheasie-- This guy was explaining about another type of method on creating a surface using patch tool for complicated shape of car body. I have experienced it before... it worked great. But can also be pain in the A$$ sometimes....It applies same way when doing NetworkSrf. But only difference is, it will not be surrounded the curves, but instead you would need to trim/spit it following the curve shape. its like wraping around the skelton. HINT! It works very well if curve are smoothed out properly.
Edit: I forgot to add this.... If you are going to do car with details, Patch Surface would NOT be recommended. It can change the curve apparence when its being trimmed/spilt. Only use it to cover the complex holes.

[cheasie]

okay i get it now, thank you all for spending the time explaning this to me.

Equinox - can you elaborate more on using network surface to model objects? anything i need to watch out? (this is kind of a broad question, but i can't think of another way to ask it)

[EquiNOX]

Cheasie-- Its depends on what model you are talking about. The only thing I can tell you to make network surface smooth is to keep curve smooth. The surface is based on how curve is aligned.

If you ever adjust curves and in a way you were not sure the curve is smooth you can always rebuild curve it will align it up neatly. And other thing, I would recommend you not to attach one network into another network. To clear on this, for example if you are going to model car doors/hood seams/lines, first make surface on the whole body then spilt, create pipe and spilt again to make a gap between two surface if necessary. otherwise you would get lumpy surface if network attach together

Hope that helps

[cheasie]

EquiNOX, are you saying I shouldn't do this in the tutorial?
http://mysite.verizon.net/res1ld7l/Network1-pages/Net41.htm

there's multiple network surfaces on the body , isn't that the only way to make complex surfaces?

[EquiNOX]

Cheasie, I am not saying you shouldn't follow Wyatt's tutorial. I think his tutorial it's good place for beginner. But.... IMO, it wouldn't be such good idea to use his methods if wishing to model replica cars such as BMW, Mercedes-Benz, Ferrari and etc. Network Curves can be pain when come into complex curves.

So, what I am saying you shouldn't combine two network surface together if they don't have same rail lines. Here's picture attached at below. You can clearly see seams or "sewing" curves. I personally don't like using Network surface when modeling car, they can always be pain for me so instead I use sweep surface which work much better.... If you haven't visit cgcars....I think I saw you once before visiting CGCars... If you look at my thread on concept car contest http://www.cg-cars.com/forum/showthread.php?t=1882 (http://www.cg-cars.com/forum/showthread.php?t=1882). All I did was using Sweep surface.... no networks, few patches perhaps.

Question, I noticed you seem going through lot of frustration perhaps struggling with surface when modeling cars? I seem to see that question has been repeated from other thread at anywhere? If so, I can help you relieve your frustation just let me know.

EDIT; Sorry I forgot about attached image....
http://i12.photobucket.com/albums/a230/APrather/Seam.jpg

[cheasie]

Thank you equinox for taking the time and making a thorough explanation. Yes, i am a member in cgcars too with the same name, sometimes I ask in different forums such as cgcars, renderosity, newsgroup, or irc channel to avoid people getting mad. Model something I love in Rhino is my goal, I appreciate your help but please do so if you have free time.

[EquiNOX]

I can clearly see you have strong goals to become skilled rhino modeler especially on cars,(because of several posts you made everywhere:) ). I can understand your are afraid push someone's button becasuse you just don't understand or is struggling with something in rhino. I can also understand, not so many people does rhino modeling or yet they don't really want to spend time teaching one other basic stuffs in rhino....I been in your shoe and of course it was frustuating for me... Just until Snecx exisit in this fourm at surface workshop, he just bacame my best teacher... I FINALLY understood thing about rhino... All you need is to understand BASIC rules on nurbs.. and the basic rule applies to surface/curve continunity Not only that, but understand what those tool in rhino are for and how it is being used. Without that, lot of things would be harder for you.... AMOF, rhino is one of the easiest 3d program that I ever encountered.... once you understand that's where you would go off becoming expert.

For example.... I assure you saw thread on my caddy concept... that was as of now on how skilled I became, 4 months ago, I never understood depth about rhino except for creating simple box and sphere, combine it and use it as boolean... I didn't understand how not curves and develop surfaces just until I started off posting question in this tread last may at surface workshop thread... with all of helps and explaination from others, Again that was about 4 months ago!
So, if its possible for me, then its possible for you... So why don't we start... post something you re struggling with and I ll see if I can help you out. What do you really need to know, what are you planning on modeling?

[Arsyn]

How about starting with wires/curves of your El Dorado?? It would be nice to know how you divided the car into its seperate shapes. I think you should know how to divide the car to know how you can build it first. Nice work btw.

[Snecx]

@EquiNOX: Yep, Rhino is easy once you get the concepts of NURBS.

One thing though, while it is true that NetworkSrf is a P.I.T.A. when it comes to complex curves, it is the only way to create surface with all 4 edges matched to adjacent surfaces with tangent/curvature continuity. Sweep2 will not be able do the job for me in these situations.

I am still trying to learn how to create clean surfaces with G3 continuity without the excess isoparms. For example, try to build a clean and simple surface to join the following 2 surfaces with G3 continuity and matching isoparms.
http://img232.imageshack.us/img232/7528/clipboard01qc3.th.jpg (http://img232.imageshack.us/my.php?image=clipboard01qc3.jpg)

I'm coming to a conclusion that such situations are results from bad modelling on the curves and nothing could help to produce elegant surfaces with matching isoparms on both U and V direction in the case above. Perhaps a rebuild is needed for that.

But then if you are not so strict on having matching isoparms over the seams, NetworkSrf does the job well. :)

I'll come up with another example soon.

[cheasie]

how do you match isoparms? what's the benefit?

[Arsyn]

how do you match isoparms? what's the benefit?

Make sure the curves have the same points in the direction you need them to join. In Snecz example, if you look at the edges closest to eachother, they would have the same point count in the U/V direction.

[Snecx]

how do you match isoparms? what's the benefit?

If we start from the basics, we know NURBS surfaces are made from isoparametic curves (isoparms) which is just a set of curves. Curves are made of points and as you know they are defined with mathematical equation.

When you have surfaces with matching isoparms, it means that the transition from one surface to another is accurate because at the seam the edge curves for both surfaces matches up--they have the same point and same equation to represent them.

If you have 3 isoparms matched to 4 or 5 (any other number) then you are dealing with two different curves/equations. Under a higher modelling tolerance, you will be able to notice that two curves can be very far apart on certain areas because they are two different curves trying to be the same.

As far as I have read, matching isoparms on surfaces is part of Class A surfacing practices. The benefit is of course better and more elegant surfaces. :)

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