PDA

View Full Version : ok whoa,wait, why polys instead of nurbs pathes again??


anoe_nomus
09-25-2003, 06:12 AM
ok, why would anyone want to split polys and extrude edges and/faces when they can just built a single optimally parametized surface, i mean achieving a fully one to one surface with polys for a character is almost nonexistent, what is the deal with 5 sided polys, i mean i did a simple smooth operation (in maya of course, what else) and the places where i had 5 sided faces, the parametization went bezerk... (trying to triangulate)

besides the ease of texturing (altough not all the time)polys are great.. but i think polys should be used for previz of andimation and rigging /or influence objects, and not for organic surfaces.
i mean in videogames they look good, for low poly counts... but if you do not know the basics of continuity and tengency (well known with nurbs), polys have no business in organic modeling.
(i split an edge and extrude that edge then i have 0 tengency between the 3 surfaces... that sucks ass)
I'll stick with Nurbs and take the texturing pain for each patch. thank u very much.
God, i lost it, i was just trying to make a simple polygonal head cheez, Maya's poly tools are great.. for building environments and non organic surfaces.

this is just my 2 cents

anoe_nomus
09-25-2003, 06:24 AM
oh yeah edge loops suck ass too... what about when i'm animating, how the hell is the surface suppose to deform when a vertex for the cheek is near the eye and one really really near the eye, when my mouth moves the eye "always moves" (although u can wheigh the vertices... still un-intuitive though for polys
... BTW i do not hate modeling with polys, just modeling detailed characters with polys always manages to piss me off...
with nurbs i have sontrol over every single isoparm spans edit points etc....

Marcel
09-25-2003, 08:39 AM
ok, why would anyone want to split polys and extrude edges and/faces when they can just built a single optimally parametized surface,

Because it is really hard to make a single optimally parametized surface with NURBS and make it look good? :)

SheepFactory
09-25-2003, 08:52 AM
I feel polygon\sub-d modelling is more like sculpting and allows me to focus on my model as opposed to the technicality of nurbs surface modelling.

j3st3r
09-25-2003, 09:54 AM
Hey boy...if you have any doubt about subdivs, checkout Geri`s Game, Toy Story 2, Gollum, and many other CG characters which has been produced with Subdiv.

You are trying to approach subdiv with a very NURBSish thinking.

There are technical, and artistical issues as well. With NURBS, you create curves, and surfaces, than attach them together, and try to convince the program during animation not to tear the patches apart.

With poly, you may model your model in a continuous surface, with a very flexible topology. Edge loops. Think of edge loops as the outlines of the charater. Muscle lines, wrinkles, folds on skin, on clothes, etc. With NURBS you don`t have such a freedom.

For the question, why would anyone...

It`s much better to have total technical, and artistic control over a model. I like to SCULPT my models intuitively, with few tools (especially splitting polys, extruding edges, etc), instead of spending my time with prethinking of stitches, surface tangents and other technical issues. One to one surface...I used to follow the following rule: What is one surface in real life, it is one surface in CG as well. So the skin from the top to the toes is one continuous surface. Cloths may be separated at the stitching, if you prefer, etc. And it is soooooooo easy to cut a wrinkle into the model exactly there where it is necessary...

Polymodels used to be subdiv cage, like your NURBS hull. with subdivision, you refine your cage, and you`ll recieve a smooth surface (again check out latest cg characters in films, which ARE mostly subdivs). You can use camera dependent subdivision values, etc.

Texturing. I don`t think, that a multipatch NURBS surface is easy to texture. Your UV is limited to one patch. Therefore each patch has a unique texture...Lot more work. With proper UV technique you can use lesser (even one) texture per model...I`m gladly pay that price, if I can do modeling with polys/Subdivs.

You misunderstand the poly technique. Check out the topics, visit www.metagons.com (look at wiredepot in Digital Sculpting section), try to find models of Bay Raitt, Ambient Whisper, Stuzzi, Rene Morel, Steven Giesler, Francisco Cortina, Mario Ucci, and many of the most talented folks around the world. And give Wings3d a try. Maya is very weak in polymodelling, because most features are buggy, or look unfinished.

Sorry for the long anser, but I hope, if you take a little more time, you gonna see, what are polys/subdivs benefits over NURBS when it comes to character modelling.

anoe_nomus
09-25-2003, 11:43 AM
oh i see now, polygons rule, i will switch to polygons, and miss out on all the good time i spend thinking and planning a character's deformation, continuity etc. since a poly model is a single surface (yay).
:shame:

well polys are not a bad modeling medium, and textring is freaking easy as hell... i just fell more like an artist with nurbs :buttrock: :buttrock:
oh well, i will try one more model, and read some insights on edgeloops and 5sided polys...

j3st3r
09-25-2003, 12:39 PM
5 sided polys are not a big deal...edgeloops are the best way to define your character.

And please, take a little surf around those names I`ve mentioned. I think, they`ve got a goooood reason why they are modelling in polys/subdivs and not in NURBS. Pixar has left NURBS for subdiv in character creation...

But, if you feel, you are more productive with NURBS, and it conforms the best to you, then why would you change?

Would you post some characters you`ve made? I became curiuous. I was modeling in NURBS few years ago, and I tried the subdiv (inspired by Geri`s Game), and it fits me much better than NURBS.

ambient-whisper
09-26-2003, 08:26 AM
Originally posted by j3st3r


You misunderstand the poly technique. Check out the topics, visit www.metagons.com (look at wiredepot in Digital Sculpting section), try to find models of Bay Raitt, Ambient Whisper, Stuzzi, Rene Morel, Steven Giesler, Francisco Cortina, Mario Ucci, and many of the most talented folks around the world. And give Wings3d a try. Maya is very weak in polymodelling, because most features are buggy, or look unfinished.


you can try to find my models thats fine. but not at metagons. haha they chose to show the worst piece of crap ive made over there.. doh haha. gonna have to talk to logan about replacing it with something more usefull and not a 2 minute sketch that looks like an abstract mess.

spakman
09-30-2003, 10:26 PM
Sooner than you think, it won't matter. If somebody is fast in NURBS, it will make it into the same engine as stuff like Polys, Sub-D's, Patches.

*edit: Don't alarm it darn it, isoparm it. But if ya lolly, better use poly. :D

marioucci
10-11-2003, 06:09 PM
Ok Martin, thats enough!!!!!!!!!

I know more about you from Travis than from u!!!!

My icq is 158050417
my MSN marioucci@hotmail.com

my email loganarts@uol.com.br

send me ur wires NOOOWWWWWW

We can also host ur timelapses (it was always a problem wanst it?)

PS. 2 minutes sketch?? haha ok!

cheers mate

Loggie

gmask
10-11-2003, 06:39 PM
I have a hybrid approach.. I like to rough out surfaces usign nurbs because you can rebuild th epatches to the appropriate degree and add isoparms easily and then covnert them to poly, merge and then eith r convert to smooth poly proxy or sub-d.

For certain type sof objects working directly with polygons make more sense but I do feel that nurbs can giv eyou more flexibility initially with organic shapes.

In the end a full nurbs model doe shave paramerterized UV"s gogin for it but they are still difficult to texture because gettign all the patch son one sheet is as difficult as unwrapping a single poly mesh model.

j3st3r
10-11-2003, 06:53 PM
To be honest, I think that hybrid approach is more time consuming than the pure version of any approach. I think there is a misunderstandig of poly tools an subdiv tools.

With maya (well known, it`s polygonal tools not so good as mirai`s Lightwave`s or even Wings3d`s), maybe you have more problem. But in Lightwave I used to spend only 4-5 hours (at most) with modelling, half an hour or one to Lay the UV out. If you have the proper poly tools (loop handling, edge cutting, etc), you have the ability to model more freely than NURBS. You are not limited to a NURBS patch`s UV space. You can add new edge`s (think of edgeloop as an isoparm) easily accross many polys. Etc.
I think poly (more precisely Subdiv) is the way to go, when it`s about modelling organic object. Although there are many talented NURBS modeller, I think polys are much more productive, and intuitive tools than the more technical NURBS technology

Peace, freedom, happiness

gmask
10-11-2003, 07:11 PM
Originally posted by j3st3r
To be honest, I think that hybrid approach is more time consuming than the pure version of any approach. I think there is a misunderstandig of poly tools an subdiv tools.


I think you aren't understanding my approach as
at all.. I only use the nurbs to rough out shapes and ignore parts of the process like stitching and tangency between patches.. once you have converted to polys you dont; ahve to worry about those things.

Most programs use beziers to generate polygions .. you can do the same thing with nurbs.. it's just another tool.

Persoanlly I don't feel like the sub-d tools in maya are plentiful enough to be useable. Also it would be really great if we could get an edgeloop tool in Maya that would offset from existing edges so you can create new edges.. much in the way that you an insert isoparms in a patch.

You say in LW you spend 4-5 hours modelling what? a box? be more specific and while you are at it if you are going to be boastfull would you mind showing this model you did in 4-5 hours.

The OP uses Maya.. so withotu having a platform specific arguement please keep in mind that he uses Maya... otherwise in soem program you would really have the optiont o use Nurbs.

j3st3r
10-11-2003, 07:46 PM
Ok, man.

This is at the end of a 4 hours session: http://w3.enternet.hu/matefy/AsianUpdate.jpg

And that`s another one: http://w3.enternet.hu/matefy/SuperHeroHead.jpg

And I understood your approach, I think very well.

gmask
10-11-2003, 08:06 PM
Originally posted by j3st3r
Ok, man.

This is at the end of a 4 hours session: http://w3.enternet.hu/matefy/AsianUpdate.jpg

And that`s another one: http://w3.enternet.hu/matefy/SuperHeroHead.jpg

And I understood your approach, I think very well.

Seems like a doable thing to do in 4-5 hours with my approach. Maybe I will time myself next week.

although I will say that I noticed that 4 hours passed in your WIP thread from where you posted the first verison of the head and the version you show an image of here.. so...

I will also say that it's is more than just tools that determine how fast someone is at modelling. I have seen people who could draw something amazing but couldn't get the hang of modelling on the computer or vica versa. Some people take to one technique more than others.

The main problem with Nurbs is mantaining tangencies and for the most part there are few reasons to use them from anything outside of product design or industrial engineering.. in those areas they still rule because the engineers need the accuracy and the control.

I talso sounds like these are far from your first model spof ehads you have ever done. Whereas the OP is not nearly as experienced.. otherwise he'd allready know the answer to these questions.

j3st3r
10-12-2003, 07:25 AM
You are right about the tools. If someone feels comfortable with NURBS, why to do things other ways? I feel more comfortable with polys, you feel comfortable with NURBS at the beginning then polys, etc.

It really doesn`t matter what method you choose, but the result is important. And if the result is excellent, why stick with methods?

I spent really a total of 4 hours doing this model. I have my job, where I do graphics for the upcoming Terminator 3: War of the Machines game, and I have my clients, to who I make highresolutional characters. This woman is just a sparetime jig. Without any deadlines or so.

Visit my site at http://w3.enternet.hu/matefy where you could see more of my work. In general my heads took about 2-5 hours to complete (with UV mapping), while the bodies (depending on the details) took more (I never measured the time). And all were done in poly/subdivs in Lightwave.

In my experience people without drawing skills suffer with modelling. They spent to much time on details, that aren`t necesary to display, hard to find proper forms, outlines etc. But that`s my experience only. Ok, drawing skills doesn`t mean modelling skills as well

Marcel
10-12-2003, 12:58 PM
4 hours for to get to that point is very quick indeed, especially because it looks very smooth and finished overall.

Do you have an tips or trick on how you speed up your workflow?

gmask
10-12-2003, 05:53 PM
Originally posted by Marcel
4 hours for to get to that point is very quick indeed, especially because it looks very smooth and finished overall.

Do you have an tips or trick on how you speed up your workflow?

Model the same type of object over and over over over and over again until you know where each polygon is going before you create it. If you made as many heads as this guy you would leanr a few things along the way to be sure.

Practice makes perfect

jeremybirn
10-12-2003, 06:19 PM
Originally posted by Sheep Factory
I feel polygon\sub-d modelling is more like sculpting and allows me to focus on my model as opposed to the technicality of nurbs surface modelling.

That's exactly it.

I used to model more with NURBS, and had to spend alot of time on the issue of how to fit them together, or how to add detail to them in one area without having too many chords bunched up in another area. Now I model more with poly/subd's (and sometimes with NURBS curves or surfaces as a starting point) and I can focus more on the form and shape, and worry less about the geometry.

-jeremy

j3st3r
10-12-2003, 06:56 PM
Marcel, in addition to gmask I suggest you that do not edit a model to the end of times...I suggest, to restart your model whenever you ar enot satisfied. RESTART, and you will follow your mistakes, and you can see your progress. Try to be not tempted to reuse parts. Practice is the key for speedy and efficient modelling.

gmask
10-12-2003, 08:34 PM
Originally posted by j3st3r
Marcel, in addition to gmask I suggest you that do not edit a model to the end of times...I suggest, to restart your model whenever you ar enot satisfied. RESTART, and you will follow your mistakes, and you can see your progress. Try to be not tempted to reuse parts. Practice is the key for speedy and efficient modelling.

Definately.. many times you can remake a shape in the same amount of time it take to repair and the second pass will be much mroe effeceint. This makes sense if you are workin with a single object.. not so much if it is a model with losts of little parts.

cheesescone
10-16-2003, 11:53 AM
i agree with j3st3er.
no one uses nurbs anymore.... well in a commercial environment anyway. polys are quick and get the job done.
as for 'nurbs are good for organic'...! i have this argument time and time again. you mustnt be looking at nature (organic) very closely....it is not dead smooth/uniform with perfect curves!!! open you eyes.
maya's poly edits are crap, thats why people go on about nurbs.
let not the technical smoother the art!:thumbsup:

CGTalk Moderation
01-16-2006, 05:00 AM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.