ZBrushCentral

Retopo not making faces..need help!

ZBrush Usage Questions
#1

I’m trying to make a very simply hand mesh. It seems like Zbrush can’t calculate these faces around the fingers properly.
I’ve deleted and recreated these edges countless times now, so I know they’re there, all vertices are attached to each other…but still I get these holes where the faces should be.
Is there an explaination? Is this type of retopo. impossible to do? This is really frustrating, I dont’ know what to do now because I really need to retopologize my mesh AND keep Zbrush’s subD levels…

I’ve attached a pic, the one on the left shows just the edges, the one on the right is the adaptive skin.

Attachments

zbrushretopo.jpg

#2

Strange. You say you redid the area seaveral times. Did you switch to “move mode” and try moving the points to make double sure they are connected to the right points or not loose? If all looks right, maybe the problem goes back a little futher that you didn’t redo.

Do you have projection on with your skin preview when this happens?

As you redo it, do you hit the A key to quickly switch back and forth the skin preview each time adding a new line to make sure it made the polygon, and hopefully find out when it goes wrong if it was working along the way for a bit.

Also, since you will project, try to that the points outside the mesh, doesn’t have to be perfect as the moment you do projection with subd levels, it will rearrange the mesh to best work with the projection.

#3

Also, looking at the image, almost looks like where the two lines meet between the fingers are not counted, and then creates a wall there with line circled in dark below.

Just to be sure, make sure the brush size is down to 1, the smallest, because if there are loose points there, a larger brush might move them all.

This is a problem most will have as they retopology, by clicking wrong or missing a point. Which is why it’s suggested to quickly hit A to preview as you work.

But I understand your frustration, I’ve had many things that just seem impossible to overcome after exhausting all options.

#4

Fingers (and toes for that matter) can be a particularly tricky part to retopo. One of the main issues, at least with me is, that you can often see points that are actually underneath the finger and can sometimes mistake them for the top points. It almost looks as though that’s what’s happening here. Nice hand, btw.

#5

This is really a problem with the algorithm’s inability to know what is inside the mesh, and what is outside, due to the fact that you just have a lot of quads/tris defined by the edges and all interconnected. I’m not saying theres anything wrong with the mesh, but unless you make the retop mesh higher res around the fingers it will never work.
I wrote a little about this here:
http://www.zbrushcentral.com/zbc/showthread.php?t=44876&page=11&pp=15&highlight=rhumba

The problem is avoided if you make the box a 5-sided extrusion, that way there are no valid 4-sided polys on the inside using the edge loop edges. I hope this makes sense, its not that easy to explain. This is happening where your fingers join the hand since there are valid 4-sided polys at the knuckles.

#6

Thanks for all the replies.

rhumba: Yes that’s what I was afraid of…seems like the algorithm just can’t support creating this type of mesh at this time.

The odd thing about it however is that it’s not only about the parts of the mesh that are right between the fingers, but it can happen with any 4 sided object, because if you look in my picture it even happens to the top parts of the fingers-although not all fingers. You’d think it would take the edge that is connecting the vertices into consideration and make a face.

I added a ring of vertices/edges to the insides of all the fingers, and it has now fixed the problem. Although I would have liked to keep the fingers low, 4 sided, but I have to compromise at this point.

Timothy: Yes I was using the Move verts tool, plus switching back and forth to/from preview mode, but I did not have project on at this time. I do want to project the mesh in the end though.

#7

In the famous and epic thread that Plakkie started (topology and Flow Lab), I 've posted a workaround that deals with the exact same problem!

 I thought then that was a temporary ZB3 bug but now I understand there is something in the algorithm.
 
 This workaround i discovered is still the only way to keep this 4sided topology,
 
 here is the [link](http://www.zbrushcentral.com/zbc/showthread.php?t=44876&page=32&pp=15&highlight=topology+flow)

i forgot to say than you can reconstruct and go tou your desired low topology

 I hope it's clear!

And for everyone that cares about retopology I suggest not to post anything until they search this thread :slight_smile:

#8

yiannis t. im too having this problem, in fact despite my threds for weeks havent had any answer. I just had a look at the work around and will try this but does this mean that il be producing a higher poly base mesh than needed using this method?

In part d where it says sellect the last mesh you made which is at Level 2, does this have to be made at Level 2 for it to work? Id like to keep my low poly mesh as my base.

Thanks.
*EDIT

I found in Page 37 of the retopo thread that the low poly mesh cant be reconstructed. http://www.zbrushcentral.com/zbc/showthread.php?t=44876&page=37&pp=15&highlight=topology+flow