You don't want of my solution?
You can divide as you want the ring!
And the form is preserved!

>> If you already have your shape in the proper form you should turn the smooth modifier off so that it does not modify the shape of your object by shrinking it down.

True, but then, curved surface will starting to look faceted.



This work pretty well on 'cubic' kind of shape


>> But I see now that one of my assumptions of how ZBrush worked was wrong - I just assumed that as you painted it would automatically subdivide polygons down as needed to get more detail in a small localized area (maybe there is an option to enable this?)

Zbrush and Mudbox allow this, to do local subdivision ... but it's not an automatic process. You have to select an area and then subdivide it.


Well I was also miss understanding what you where all trying do here :P
But yes, actually if you only use the meshing tool to create dense enough models, this should work pretty well for some light sculpting work, no matter if there are triangles or not. For me using zbrush = subdivide you model in zbrush, so I was a little bit surprised by the discussion.

>>You don't want of my solution?
>>You can divide as you want the ring!
>>And the form is preserved!

... show me :)

Hi PaQ - an example:

Save from MoI as evenly sized polygons - here in this case I actually used triangles only, no quads of any type (it's certainly ok to use quads, this is just to demonstrate):




In ZBrush, subdivide if desired with smoothing modifier off, then I have no problems in doing displacement:



As far as I can tell everything is behaving perfectly despite having no quads around at all.

For these kinds of purposes where you have the base model formed with edges and smoothing already built into it, it is not "quad" structure that is important, it is "evenly spaced" structure that is important.

When you have the correct base shape then disable the smoothing modifier if you want to do additional subdivision and all is well as far as I can see.


If you want to use ZBrush more as a full modeling tool to make large changes to the fundamental shape, then that is a much different task. Certainly having quads could be helpful in that kind of a situation. I don't recommend using MoI generated geometry for that kind of use, but it should be perfectly fine for the kind of thing that I'm illustrating here...

Unless there is something really wrong with my result that I am not noticing?

- Michael

Hi PaQ,

> True, but then, curved surface will starting to look faceted.

It looks like you a have a low resolution starting mesh in that case.

If you divide up your initial saved mesh out of MoI to have like 10 times as many polygons as that it should reduce that problem down to the point where you can't detect it.

With a high initial and evenly spaced polygon count of MoI you should get good results from both curved pieces as well as sharp-edge ones - just applying the smoothing type division always can mess up your shape around sharp edges just like you showed previously, I mean it actually mutates your shape and changes the form which is bad if you have the shape as it is supposed to be formed.

- Michael

Like this? Divide one for the top
Twice or third for the Bottom
It's the pole who make problem so you must divide in 2 pass! like explain above;)
Export from Moi without any regulates except Quad + Triangles and Weld edges

Hi Michael,

Sure, it was just to show what's actually append to the geometry. Indeed it might be a solution and allow an extra subdivision step inside zbrush.

But all in all I still don't think it's a viable solution in real production compare to a traditionnal poly modeling.

The olga's ring will take 800 polys as a base mesh with a traditionnal poly method (parobably full quad), will allow you to subdivide it until 10.000.000 of polys in zbrush (or even more with the HD subdivision, which seems to do a smooth subdivision, you don't have the choice) whithout any shape alteration ... and you'll finish with just an image as a displacement map (+ a normal map maybe) that can be used on the low base mesh to rebuild the model in any rendering software.

What will be the polycount of the MoI base mesh ? How far could you divide it in zbrush without alterate the shape ? (curious to see Pilou example) Will you be able to just bake the displacement map, if yes how apply it back in a render engine like modo or lightwave, that can only handle displacement in sds (catmull/metanurbs) . (that means that the base mesh will have triangle pinching as the example showed above).

Time to sleep a little bit now, I hope I'll have some time to experiment it myself too.

Hi PaQ - yeah this approach will not be good for that kind of a process of trying to have a low poly count base mesh and then a displacement map in a render engine.

But that is not typically the goal of this process - instead this use is to make a highly detailed mesh that will be exported eventually as an STL file and then cut with a milling machine or done with a rapid prototype machine to eventually create a mold.

For example, a rapid prototyping machine does not understand anything about displacement maps or low poly cages or subdivision surface smoothing, it just takes a big bunch of triangles.


For the purposes of wanting to add some sculpted or relief detail to a piece that is going to be built as a mold, this whole process seems to be a very viable and good solution to me, I mean I showed an example above of the basics working.

The polygon export from MoI is completely suitable for this kind of process.


It is not going to be good for the goals that you were describing, but that is not the situation that you would use it in.

- Michael

@ Pac
I have exact same result than Michael above except the fact that I have enabled quad+tri and don't make as small as ;)
So mesh drawing is different with adorable circumvolutions :)

But I will like to know how Michael divide without the Pole problem?

Here the ZTL zip file http://www.divshare.com/download/5503850-95c 4.5 megas
300 000 polys (Top and bottom divide 3 times) OBJ was 5400 polys from Moi

(click on "Download this file") and wait 15 seconds, the downloading will be begin!

Hi Pilou,

> But I will like to know how Michael divide without the Pole problem?

I'm sorry I'm not quite sure which problem you are mentioning - is it the problem with the pole of the sphere in the original message of this thread?

If I export a sphere with "Weld vertices along edges" enabled, there is no divide problem at the pole of the sphere, if you export without welding enabled then there will be that problem.

- Michael

Also Pilou, I would recommend dividing to a smaller and finer level of polygons when you export from MoI as I showed in that previous message. To do that, use the "Divide larger than" setting and also switch the dropdown to "All" to apply it to all surfaces, both planar and curved.

You will probably want to divide it to a pretty fine level in MoI first because that will help to preserve more of the curved shape of the object, since when MoI adds polygons each new point added will be along the true original NURBS surface. Then you may want to subdivide perhaps just one time in Zbrush with the smooth option off.

If you make a much rougher version out of MoI and then try to subdivide in ZBrush with smoothing off, the original rough polygon structure will be more apparent in your model.

- Michael

It's the same problem than Olga: at the first dividing if I don't separate Top and Botom there are crash lines!

Else I have no problem for make deformation or any else transformation :)

Here some sculpt and grid texture Transparent apply (*15 H&V) on the divided mesh above

Hi Pilou, what are "crash lines" ? You mean some spikes that kind of shoot across the model?

I saw those too if using the "Smt" modifier, looks like it may be a bug in ZBrush.

To solve it turn the "Smt" modifier off before you do the divide.

- Michael

Aaaaaaaaaah!
"With SMT Button pressed mesh will be Smoothed then Divided"
Forgot this damned button (that arrive with this Boeing's Interface :)
All is fine! :)
So export from moi to Zbrush is cool in OBJ format for some crazzy sculptures

PS So my trick was useful but unnecessary :)

"With SMT Button pressed mesh will be Smoothed then Divided"

Hi Pilou,

> "With SMT Button pressed mesh will be Smoothed then Divided"

Yes - it looks like ZBrush has some kind of bug in the smoothing process, looks like it may have to do with processing polygons that have a high valence vertex in them. That's a vertex that has a large number of edges radiating out from it, which is the case in pole points like that.

Vertices with a high valence can have some difficulties in certain smooth subdivision schemes.

So turning off the smoothing process avoids the problem in ZBrush.

- Michael

Very informative thread.

In ZBrush if you turn on Polyframe while using Dynamesh you can see that the mesh is made up of quads and triangles.

Here's a cutlass made in MoI and imported into ZBrush using the method previously outlined.
MoI




ZBrush

http://www.elancejeweler.com/modeling_tips.html

Cool link Colin, Thanks!

This method is also excellent for bringing MoI models into 3D-Coat for voxel sculpting!