Alien head - geometry grieves

[Skaven252]

Heya all,

First off, I'd like to say: I've been itching to get back to ZBrush. The reason for me just occasionally dropping in and commenting lately, has been that we've had an insanely busy period at work, and I haven't had time for anything else. Now I finally have at least some time.

So, for starters, I decided to model a Khausar head in ZBrush. "Khausar" is an alien species of my creation, that looks something like a cross-breed between a wolf, a lion and a rat. Heavy Warhammer 40k influence, of course. I have already made several drawings of the species in 1997. Here are some:

:b2:Head studies (http://www.futurecrew.org/skaven/artwork/gandakk.gif)
:b2:Growling (http://www.futurecrew.org/skaven/artwork/warcry.gif)
:b2:Berserker (http://www.futurecrew.org/skaven/artwork/PanzerRat.jpg)

First off, I started with a unified skin of a ZSphere lump. It worked nicely, until halfway through the production I went like, hey, I'd actually like its mouth to be open. So I masked the lower portion of its jaw, rotated it to open it, then masked the mouth area and hid the polygons. And got really nasty, jagged edges. Then I thought I could even out the polygons by creating a Unified Skin, but it didn't help much, plus a lot of detail was lost in the process. See below:

http://www2.zbrushcentral.com/uploaded_from_zbc/200310/user_image-1065079550wbb.jpg

That one went to the trash bin. Oh well. So my next approach was to create a ZSphere Adaptive Skin, to produce a bit better base topology for the head. BTW, the initial ASkin looks very much like a dinosaur head. ZBrush seems like a great too for producing dinosaurs. I guess Pixolator knows this, having seen his recent teasers? :)

Anyway, after a while of modeling, dividing and sculpting I started getting some nasty creases in the smoothed & divided version of the model, which I can't seem to get rid of (circled in the large version). The reason is the underlying topology with badly angled, overly long edges, which seems really hard to fix. Man, sometimes I wish I could weld/divide individual vertices. :(

http://www2.zbrushcentral.com/uploaded_from_zbc/200310/user_image-1065079806acq.jpg

I thought I'd share the results so far with you, and ask if any of the seasoned ZBrush veterans here have any advice. How should I continue? All comments greatly appreciated! Thanks.

(The ears, you wonder? My plan has been to model those separately. Same for the teeth.)

[Bonecradle]

Hi Skaven

It is hard to tell what the problem is like without seeing the mesh for the latest model with creases.

If it is still low poly, you should be able to get rid of them by dividing and smoothing more. It is usually best to smooth after each time of dividing so long as it doesn't remove wanted details. But it sounds like you did that already.

[Skaven252]

Thanks Bonecradle,

The fourth small model in the upper right corner actually is the mesh. The large one is a version where the Smooth, Subdivision and Edge Smoothness parameters have been increased. With Quick Edit mode and Polyframes the head looks just like the one in the upper right corner.

(I'll post a larger version later, if needed)

[Bonecradle]

Ah, OK :)

It looks then like the creases are from buckled individual polygons, rather than from problems with the mesh, which seems very clean.

If you don't mind increasing the number of polygons, do a divide (or maybe two) and then smooth it.

[Frenchy Pilou]

Hi SKa
Why not divide and smooth "just" the aera concerned ?
Pilou

[cameyo]

Hi Skaven252,
maybe the problem is with TRI polys...i can see some of these (TRI) in your last model (before skin)...
But i have no solution (export and import may help).

cameyo

[Skaven252]

So it is a known fact that triangular polygons cause these kind of problems? Hmm, that's good to know.

[PusGhetty]

Hey Skaven,
Cameyo is right about the tris... There are two work-arounds for this though:

1. Before you mask an area of the adaptive skin mesh for dividing you must export the adaptive skin as an .obj and then import it back in again. For some reason ZBrush doesn't like mixing tris and quads unless you force it too. Once you import the model back in you can then mask and divide to your hearts content. Though I caution you to realize that when you divide certain areas of the mesh you cause the mesh to be asymmetrical.

2. Secondly you can just build up the model with subdivisions of the mesh as a whole. This will keep the mesh intact and completely made out of quads... this is the preferable way as far as I know.

Check out this link (http://www.pixolator.com/zbc-bin/ultimatebb.cgi?ubb=get_topic&f=4&t=000598). It's too bad, but either way means that you will have to resculpt this cool creature.
Best regards,
Michael

[Zoid]

Hi Skaven,

I have the same problem, too much work and not enough time for ZBrush. When I have time,I have been exploring making very detailed ZSphere models with tight corners like around eyes and mouths. It is very interesting to read about the tris and quads thing. I like to stay with all quads because they work well in Lightwave subdivision modeling. Bonecradle is right, you get less kinking with a denser mesh, I like to start at '3'. Here is a quick script I made. If you see anything in it that is helpful I can add some notes and explanations to it.
CrocHead.txt (http://www2.zbrushcentral.com/uploaded_from_zbc/200311/user_file-1065113375rxz.txt)

I like your creatures. I am making something similar that looks like a dragon-dog.

[Skaven252]

Thank you, everyone, for your comments.

Oh well, I guess I'll have to start over once again, this time sticking with quad polygons and dividing a bit more daringly. I shouldn't be afraid of using a huge amount of polygons, anyway. ZBrush seems to handle them just fine.

BTW, looking at the jagged edges of the creature's open mouth in the first image, I got this thought. This idea. Wouldn't it be cool if there was a feature that allowed you to stroke a line across the model, and the program would re-arrange the polygons and turn the edges so that there would be a uniform edge traveling along the stroke? It would be great for creating smooth corners in places like eyelids, or the edges of the lips, and such. Just a thought.