Modelling: Problems with creating a clean corner for a mouth

[Dave Black]

That shading problem looks to be coming from a pole.

A pole is a vertex with less that or more than four edges emminating from it.

Terminating geometry resulting in N-gons is a common practice, though the corner of the mouth is probably not the best place for it.

Have a look through the "Theoretical Sub-D" Thread in the sub-forum...Lots of good stuff on this type of thing. It's a massive thread. Just look through the first 5 pages or so. It should explain a bit more about N-Gons, Poles, etc.

Hope that's of some help...

-3DZ

:D

[James Bending]

Blimey, i didnt know that the theoretical sub-d thread includes stuff like that. (I still am trying to define what SUB-D actually is)

But thanks alot 3DZealot

James

[James Bending]

Hello again. I am very new to 3D studio max and I have the most basic of problems with vertices that I am sure could be answered simply. I didnt seem to be able to pull out the information i had wanted from the theoretical sub-d thread, as useful as the thread may be there is alot of advanced discussion and use of terminology which i did not understand fully.

I basically need to know how this extrusion / crevice should be modelled.

From there i can work out how to create most of my other corners.

Below are images of the example corner.

http://www.jamesbending.co.uk/3DSMAX_four.gif

http://www.jamesbending.co.uk/3DSMAX_four.gif


http://www.jamesbending.co.uk/3DSMAX_five.gif

Thanks alot for your patience and time ;)

James

[Schnupps]

I suppose you are going to use meshsmooth above this lowpoly object. You should (in most cases) first do a little extrusion, like the size of the little polys before the extrusion, and than a bigger one.
And the vertices, which end in a straight edge of the poly are not so good.
For the mouth, just try to chamfer the outlining edges of the mouth, to get rid of this smoothing error.

Schnupps

[nimajneb]

I've attached a GIF show how I would begin with this. Poles are your friend, if you control their placement. This solution moves the pole back into the chest section of the mesh. I generally try to do my extrusions from a ring/loop combo as opposed to a arbitrary face. In that way, I'm continuing loops from the piece I'm braching off of, not starting new one based on artifacts of the structure. Remove the extrusion you've done, and start from an edgeloop like this.

[James Bending]

Yay! I kinda get it (i would of attached a picture of the result but FTP is playing me up), thanks alot everyone (Schnupps, 3DZealot and nimajneb) and anyone who contributed to my other thread. :)

Sorry - nimajneb yet another question, you have a 5 sided face (n-gon? I think that is what its termed as in the theoretical sub-d thread) and in the meshsmooth there seems to be a vert with 5 sides attached to it (dreaded star pattern), although not so noticeable. Anyway to make this n-gon a quad?


James

[nimajneb]

There are many ways you could quad that pentagon. However, this will not eliminate pole (in fact it may create more of them). The pentagon (or the pole) results from intersections of two or more groups of edgeloops which go in different directions. To bridge the gap between them, and some point you almost invaribily end up introducing non-quad faces. Pentagons are preferrable (in general) to tris. Both create poles when smoothed (the star pattern). I'm attaching an image to give some examples. In image one, you see the smoothed pent. Notice the pole. In image two, I've quaded the pent, introducing a new pole farther into the "chest". This pole carries into the smooth mesh. This is one of the arguments for an all quad mesh. In this way, you control the creation of poles. There is a counter argument however (gets technical) which I'll provide a link to here about the virtues of letting the smoothing create these poles for you. Again, poles are not automatically bad. You just want to control where they happen, as that they can cause problems with deformation. SImilarly pents are not necessarily bad, they can cause problems with texturing. See the linked thread for more info on that.

Pent Smoothed
http://nimajneb.com/images/pentagon.jpg

Pent Quaded - Pole, Smoothed
http://nimajneb.com/images/quad_w_pole01.jpg

In Praise of 5 Side Polys... (http://cube.phlatt.net/forums/spiraloid/viewtopic.php?TopicID=23#221)

[James Bending]

Hello,

Thank you for replying with such detail nimajneb (the diagrams were great!) I shall look into that link you provided. I now understand that its ok to have a 5 sided edge (pentagon, n-gon?)or atleast try to move it away from areas which will require animation:). Is there anywhere I could perhaps download .max files with good qaulity examples of 3D models? That might help with something to refer to. Anyway thanks alot for your time, its greatly appriciated!

James

[nimajneb]

I wish I could say yes, there's an open community of mesh sharing out there, but it's just not been the case in my experience. People spend a lot of time on their meshes, and do not want their work plagerized. I believe the 3D Festival site has a collection of character models available as free downloads. I don't know that they're .MAX files, but it would be a start. If you search out some of my old posts on Spiraloid, there's a few .max files there you could see. Also, you could see if you can get a hold of Nendo's installer. The scripts for the Motley bird character, you would like find informative.

[Dave Black]

FWIW, I have supplied a simple mouth model for use as a teaching aid on my Sub-d thread if you are interested.

You can find it here:

http://www.cgtalk.com/showthread.php?s=&threadid=40373&perpage=15&pagenumber=35

The links to the downloads are on that page.

Dunno if it will help, but I thought I'd mention it.

-3DZ

:D

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