View Full Version : SubD TIPS & TRICKS...

 ilasolomon06 June 2002, 02:41 AMhi let's start a thread about tips & tricks on modeling methode specialy the most favorite one SubD surfaces...in MAX i made this simple box:
ilasolomon
06 June 2002, 02:47 AM
then i didn't add any polygon to it, no edge extrude or face or
vertices added...just twiking some parameter in editable mesh
& then applying meshsmooth modifier, i got this:
could anyone tell that what i did to achive those smooth/beveled
edges from that simple non-beveled box?! :)
& i must mentioned that i did nothing to mesh-smooth sub level
controls like crease edge or weight of vertices. in fact they don't work like that.

Chris
06 June 2002, 02:52 AM
:wavey: Pick me! Pick me!

errr, Smoothing Groups?

ilasolomon
06 June 2002, 02:54 AM
HAHA! yes smoothing group, but i need more detail! there is
a little trick ...

Chris
06 June 2002, 03:00 AM
um, is it checking the 'separate by smoothing groups' checkbox in meshsmooth, Mr Solomon? :applause:

ilasolomon
06 June 2002, 03:13 AM
POOF!...i'm worried i didn't understand a word of your sientific
article...sorry! more explaination pleasssse! :)
anyway...my trick is that i applied 2 mesh-smooth afterward!

this is what happend to regular mesh smoothed box:

ilasolomon
06 June 2002, 03:16 AM
by smoothing group difination:

ilasolomon
06 June 2002, 03:19 AM
by first mesh-smooth modifier with smoothing-group based iteration we have this:

ilasolomon
06 June 2002, 03:21 AM
& with second regular mesh-smoothing methode...:

Chris
06 June 2002, 03:31 AM
Dammit! So close... :( Oh well, I guess the chocolate fish goes to someone else... :bounce:

"Oops, just realized you wanted Max stuff. Well, this might be useful. Dunno how meshsmooth interpolates."

Catmull-Clark I believe, or some variation or that so your advice should be right on the button... :)

psil
06 June 2002, 09:07 AM
">>Actually, I'm starting to develop a new smoothing algorithm that retains volume with low vertex count" ...sounds good, Marc!! Will it smooth ngons?

I read in Dec issue of Computer Arts that XSI 2 has "...a subdivision algorithm that's one of the best we've seen enabling you to use polygons with any number of sides while still generating clean and smooth surfaces."

Can anyone confirm this??

genesis max
06 June 2002, 04:49 PM
I think this thread would be very usefull in understanding of how Sub-d works and your example was very usefull.

ilasolomon
06 June 2002, 09:47 PM
hope so!
ok this is a more complex test:
this is the original polygonal cage

ilasolomon
06 June 2002, 09:49 PM
now carefuly modify the smoothing groups...& first mesh smooth
by SG:

ilasolomon
06 June 2002, 09:55 PM
& with the second mesh-smooth , this time regular SubD:

ilasolomon
06 June 2002, 09:57 PM
the final touch-up:

kreno
06 June 2002, 07:50 PM
Why did you give batman an old woman's puckered kissing mouth?

ilasolomon
06 June 2002, 10:44 PM
:D sorry...will never be happened again!

kreno
06 June 2002, 10:48 PM
Ok, just don't let it happen again.... and make sure he doesn't receive nipples either you hear me?! lol

ambient-whisper
06 June 2002, 11:16 PM
Originally posted by Marc McChesney

Actually, I'm starting to develop a new smoothing algorithm that retains volume with low vertex count, unlike Catmull-Clark, Doo-Sabin, and Chaikin methods. Although Chaikin uses a corner-cutting refinement that is fairly close to the general shape, it is difficult (if not impossible) to implement that with multiple polygons. So I'm looking at something similar to Cardinal splines but more effective and easier to use.

Hmm, sorry if that was off-topic.

Oh, also, keep each vertex having four edges intersecting it. And watch your topology. It is more important than anything else while modeling (besides actually modeling the form =] ).

n-gons, while able to be subdivided by Catmull-Clark, produce pinching as a result of the average of the face being in the center of all the vertices of the face, thus resulting in huge edges that span radially...

Oops, just realized you wanted Max stuff. Well, this might be useful. Dunno how meshsmooth interpolates.

mirai has something like that. but its kinda useless since you cant retain history :/

Are3D
07 July 2002, 03:38 PM
SubD's are not very friendly to triangles. Try to only SubD quads. You won't get good deformations with that kind of topology.:hmm:

paconavarro
07 July 2002, 09:35 PM
:applause: :applause:

:thumbsup:

The Magic Pen
07 July 2002, 02:10 AM
Yes this thread = good stuff..more more more !!:airguitar :buttrock: :eek:

JFrench
07 July 2002, 01:32 PM
Like Are3D said, don't use triangles with subdivision surfaces. Even though programs like Lightwave can handle them, it doesn't provide clean deformations if the object will be animating. there is ALWAYS a way to get only quads, but if you feel you can't find a way to re-work a triangle, make a five sided face instead.

diamond quads are ok too, just don't use them in spots that will move a lot like the neck, shoulder, or thigh.

JFrench
07 July 2002, 01:53 PM
Oh, and about that Batman mesh:
First of all, like I mentioned before, triangles shouldn't be subdivided. If you want that character to be a subdiv, rework the geometry into all quads.
there is a point between the shoulder and chest where you have 9 faces all coming together at one vertex.......BAD.
You should never have more than 5 faces coming together at one vertx.

AJ
08 August 2002, 11:40 AM
*Strains whilst pulling this thread back to the top...*

Hnnnnghh.... ahhhh.

Very nice pointers about smoothing groups Mr Owl! I've never actually used them properly for anything of purpose, and now I will! :D

Oh and,

there is ALWAYS a way to get only quads, but if you feel you can't find a way to re-work a triangle, make a five sided face instead.

Which lets face it - looks brilliant anyway!

ilasolomon
09 September 2002, 07:26 AM
hello AJ_23, :) hope i find some more tips to put here.
i didn't see much n-sided polygons (not 4 sided) on that mesh,
actually those 5 sided on the neck were created by chamfering
the vertices in corners.

ggg
09 September 2002, 08:36 PM
Originally posted by AJ_23

I agree quads are often inefficient and revel the model to be quad like/grid like especially in motion, other shapes can follow anatomical deformations better.

tubby
09 September 2002, 08:59 PM
im using max but am trying to learn maya and i was wondering if there are smoothing groups in maya also? and if so where can i find the menu?:) :)

bulon
09 September 2002, 10:18 AM
hi,solomon,i cann't make it in your way ,please give me more explanation,,thanx ,,,:) bulon

bulon
09 September 2002, 10:20 AM
second step:hmm:

ilasolomon
09 September 2002, 09:48 PM
hi bulon, you should use SMOOTHING GROUPS
select the faces (polygons) in one side of the cube then
in the edit mesh>polygon sub: smoothing groups
assign an unique smoothing id to them, then in the meshsmooth
modifier set the 'result' to 'smoothing groups'.
i'll explain more if you can't do it again.

ambient-whisper
09 September 2002, 12:32 AM
instead of using smoothing groups you could also use creases. turn yer object to nurms, picn an edge and bunp up crease value.

bulon
09 September 2002, 04:02 AM
solomon,thanx!!!!
:bounce:

ilasolomon
09 September 2002, 05:22 AM
ok
this is a tip about how to work with SubD modeling in MAX like
MAYA's workflow

you are making your model by low-poly mesh, but want to see
the resulting mesh always, but MAX' 'show end result ' looks
a little unusable!, just do this:

1. make a copy of your polygonal mesh as "Reference"
2. assign a meshsmooth modifier to the Refrenced copy & set the
tesselation to 1 or 2 in viewport & 2 or 3 in rendering.
3. assign a 'mesh select' over the 'meshsmooth'
4. assign a wireframe matterial to the first polymesh & make it
'not renderable'

now you have a PROXY Polygon mesh & a smoothed version are
seperated like Maya, if you modify the "proxy mesh", the smoothed
version's shape will change but you can move the smoothed to
the left or right, scale or could use some other modifiers on it &
no need to turn on the 'show end result' & off again!
you also can turn the proxy mesh "see through" instead of "wire"

artistx
09 September 2002, 02:22 AM
I think I have a pretty good idea of what you're talking about. I never thought about doing it that way. Ila_Solomon, could you show us a screen capture of this proxy/subd setup you have in max? Thanks

ilasolomon
09 September 2002, 10:11 PM
sure!
here it is:

http://www.topleftpixel.com/ila/temp/polyproxysample.jpg

urgaffel
06 June 2003, 02:20 PM
The only downside I see to using your method is that you get a lot of useless polys... I mean, you could chamfer some edges to get those smooth corners which receive highlights instead of slapping on two meshsmooth modifiers. It will need some tweaking to get rid of pinching, but the end result won't be as dense as yours.

*edit*

I also strongly recommend browsing the subd thread here: http://www.cgtalk.com/showthread.php?s=&threadid=40373 and the Spiraloid forum for more insights about subd and how to model with it effectively...

plaguelord
07 July 2003, 03:53 AM
thanks solomon, the proxy tip is very useful!

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