CGTalk - Subdivion Sufraces, Good\Bad ?

ME3D

03-06-2002, 10:57 PM

I have a big fan of the solid modeling feel of sub-d's.
I definitly believe its increased my speed and detail in modeling. This isnt just because sub-d's are kick as or somthing I think its really more due to the fact they're intuitive....gave me a new approach to modeling.

Jhonus

03-07-2002, 01:00 AM

what about texturing with Subdiv's in Maya?

i heard there were a few 'issues'.

eat food.

Lyr

03-07-2002, 01:07 AM

none that I have encountered. They texture just polygons.

Jhonus

03-07-2002, 02:06 AM

interesting...

so are there any major advantages/disadvantages over using subdivs as opposed to the connectPolyShape method?

are subdivs slower, faster or the same as polys when it comes to displaying them in the viewports?

Grooveholmes

03-07-2002, 03:03 AM

Subd's are awesome and they are very fast until you start refining the detail alot. Once down to the 4th or 5th lvl of detail they tend to gobble up memory pretty bad. But you really or rarely will need to refine to that level. It'll also bog down pretty bad when you switch to poly proxy mode in order to do things like extrusions and merging verts. Luckily you'll should only have to stay in that mode breifly. I can't comment the texturing end of it. I can't even get my stinking uv's right for good old fashioned polygons. All in all the the goods far outweigh the bads. Go ahead and play with it.

ME3D

03-07-2002, 10:06 AM

Texturing in sub-d's works fine for me, but in version 3 it was screwed up. All fixed now so......all smiles.
Grooveholmes: I tend to just get a base with the poly cage of sub-d's first.
Then go for the detail in the standard mode. Mostly never returning to the cage. This keeps the speed up and eliminates any "quirky" things that may change due to extrusions.

Lyr

03-07-2002, 11:57 AM

Hey ME3d, have you played with propogate hierarchy at all? pretty strange feature, but I bet it can be damn useful.

ME3D

03-07-2002, 12:37 PM

Uh...... LYR
Im afraid you have me at a loss. Where could you direct me to for documentation on that? (its not in help files.)

Anchuvi

03-07-2002, 01:23 PM

So the general feelign is they are good then...

How are they when rigging the character ? Is it as easy as when riggin pollys ?

Lyr

03-07-2002, 09:10 PM

Hehehe there is no documentation for the propogate hierarchy feature =( It's on the shape node of the subd under hierarchical edit behaviour, it defaults to ignore, but propogate does some funky some stuff. Try modelling something in hierarchy mode, switch to poly proxy, turn propogate on and then use split poly and cut over the area you modeled with hierarchy edits.

ME3D

03-07-2002, 10:24 PM

LYR,
Thats not funny man.......
You have too much time on your hands! Go get to work dammit!

Now really, Thats cool I'll check it out. I would like to find some more diversity within my sub-D modeling. My side short is taking more time at present, so it isnt allowing me to delve into many areas. I'm focusing on rendering, lighting,texturing, aspects to stay semi focused.
Thanks for the tip.

Lyr

03-08-2002, 12:08 PM

Heheh yeah I try to stay focused too. Maya is just too damn deep to allow me to stay focused on one thing for too long. I should just delete the node and mel command referance docs from my hard drive, they are just too damn distracting.

ME3D

03-11-2002, 12:17 PM

LYR,
Got a break and checked that out a bit further. Looks like the problem I usually have in modifying the polys after details have been added in standard mode is fixed.
Thanks man. I have just gotten use to only doing base modifications in the poly mode of sub d's then focusing on the details in standard. Looks as if the mesh instability is mainly due to the propagate hierarchy being defaulted to ignore. Adaptive lines stayed intact even on a complicated character model!!!!!.

Who needs poly's and nurbs when you have sub-d's!
Thanks again for the tip.
You entering the challenge this month? May be fun to get you, me, and alex into this one. If work is slow I have a chance.

Lyr

03-12-2002, 03:02 AM

That's awesome you figured out what the hell that was for. I guess I need to work on my testing methods a little more. Perhaps I will start to work more with subd's now, been mostly sticking to poly modelling and the doing fine detail work with subd's like fingernails and subtle plane breaks.

I probably won't be doing the challenge this month, got too much crap I have to stay on top of, really rough workload this semester.

ME3D

03-12-2002, 07:45 AM

LYR,
Too bad no time for the challenge. I honestly dont have time either, but as usual i'll try and overextend myself....lol
Although the gods thing was not my first choice.
Where are you attending school at?

Sub-ds for fingernails was mentioned.....lets post a pic each and talk technique. Although the technique may change now you've found the options for propagate.

ME3D

03-12-2002, 10:03 AM

sub-d ALFRED hand (early stages at about 5hrs in)
Alfred here is quite a bit further now, but this model is pretty standard for quick detailing. Sub-d's easily won me over, even though I still build in the best suited modeling area for the project ( nurbs, polys) I seldom have cause to stray far from sub-ds as my main model.
Yes they are cool!:cool:

Lyr

03-12-2002, 10:16 AM

Cool, I'll probably be building some fingers tomorrow, I'll try it with subd's and propogate and see what happens.

Also I go to the Academy of Art college in San Francisco USA. It's pretty cool, but the teachers in the 3d dept are way to easy when it comes to crits.

ME3D

03-12-2002, 10:22 AM

The details on the new version are somewhat more detailed, but I think the propagate may warrant a quick redo. Maybe this weekend. So much to do so little time.

Lyr

03-12-2002, 10:26 AM

Wow propogate makes that much of a difference?

ME3D

03-12-2002, 11:58 AM

Without sounding to stiff I must quote the great Mies Vanderoeh( dont know if thats spelt correctly)

"God is in the details"

Just kidding....Yes it does make a pretty big difference, as i thought about it....Im still a bit afraid of using it on a model thats pretty far along in the standard hiearchy. But its really alot more use during the modeling process to switch back and forth, like sub ds are meant to, but as I said before the previous version and this one are unstable as to results. The propagate seems to fix this....

Lyr

03-12-2002, 01:30 PM

Ok, this is too cool. Been messin around with it a bit more. Why the hell did AW auto gimp subd's? and why the hell didn't they document the propogate flag?!?! Absolutely unreal. Oh well get the word out, subd's aren't broken.

It seems to be stable on meshes with fairly deep hierarchies, albiet slooooow. And sometimes a display bug will pop up showing the model to be detached along an edge, but it's really not. And when switching between proxy and standard the hierarchy edits will "flatten" out and you will need to "fluff" your higher level edits by doing a quick a trasform on a lower lvl to get the lower levels back to normal size

Heh, I wonder if the guys in charge of the docs are among the unemployed now.

Lyr

03-12-2002, 01:39 PM

If you have done hierarchy edits on a mesh with propogate set to ignore, you cannot change it to propogate and continue editing your mesh, it will do some really nasty things to your mesh if you do.

So far it seems that polys converted to subd's with the resulting subd mesh having levels beyond 0 are immune to this if you turn propogate on before doing any edits.

rsalonen

03-12-2002, 09:15 PM

Hey ME3D, regarding that hand (which looks really awsome! ;) ), do you start with a subd cube or do you like make a polygon cube and then convert it? what's the best method?

ME3D

03-13-2002, 08:40 PM

Lyr with what you just wrote you should be the person covering documentation, testing.....lol
Wonder if you could send that to A/W to place in?
Yeah the person documenting was probably also programming, so A/W should really just pony up and hire some kid to do the documenting. Or we could all just start sending in our findings...hehe

Vetque
Thanks. I still use the poly> then convert. Since it automatically places in 2 section fro the sub-d cube. But you cant do much to the cube before converting so I try and stick to the basics, number of sections>convert to subD.

SpaceJASE

03-16-2002, 06:41 PM

I guess I'm not clear yet (from this thread and a bit of experimenting) on what "propogate" is doing to my model and if it's good or not. Is a propogated model more stable or something? I'm curious now...

I was down to level 3 and those details seem to have been lost somewhat.

Have y'all skinned a propogated model and an un-propogated model and noticed a difference?

Lyr

03-16-2002, 08:25 PM

The apparent loss of detail is a display bug, it's really still there, move the faces around the detail around a bit then undo. You might also get a bug that makes it look like the surface is broken, but it's not.

SpaceJASE

03-16-2002, 10:04 PM

yeah, I got the broken surface thing and it went away after moving some verts.
I couldn't get my detail to come back and everything was jacked all to heck... until I did "clean topology" and it fixed itself...

funky

Lyr

03-16-2002, 10:12 PM

Perhaps the subd mesh needs to be updated in a certain manner to correct that. It definately warrants looking into.

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