ZBrushCentral

How do I create more than one polygroup?

ZBrush Usage Questions
#1

If I have a model, I can paint part of it then under the polygroups menu I can select Create from polypaint and it makes a new polygroup in that shape. If I want to then create another new polygroup, I tried changing the colour I was painting with (thinking it would interpret this as me wanting a different polygroup). But it seems to just add it to the group I already created.

So my question is how do I get zbrush to create more than one polygroup? i.e. how do I make it understand to create a new one, not just add to the existing one.

Don’t know if I am making myself clear. Hope so…

#2

I most often times use the “Group Visible” action. So just hide everything you want to not be in the group and press that button. I think the hotkey is alt/command W. If wireframe is displayed, it will change color so you know it is a separate group. If you keep hitting the button or pressing the hotkey, it will cycle through colors.

#3

The quickest way is to paint a mask (hold Ctrl and draw) where you want the polygroup and then press Ctrl+W. Turn on polyframes (Shift+F) to see the result.

One thing to remember is that polygroups should be created at the lowest subdivision level (if you have subdivided your model). This is so that the polygroup remains consistent on all levels.

#4

This is really helpful. Thanks!

One question though, I find the mask produced is quite blurry, so it’s not obvious which quads have been selected for the new polygroup. In other words, I can’t make a very precise selection. I tried adjusting the focal shift, but it doesn’t seem to make the mask brush any sharper.

#5

Masks work on points rather than polygons so they will always appear slightly blurry because points are generally shared by more than one polygon. (This means that a polygon that has two points masked and two points unmasked will only be masked by 50%.)

You can sharpen a mask by Ctrl+Alt+clicking on the mesh but this won’t get rid of the slight blur at the edge. Higher resolution meshes [more polygons] produce sharper masks but only because of the larger number of polygons.

So for creating polygroups it’s a slightly rough-and-ready solution.

For more precise control it is best to use the selection brushes (Shift+Ctrl+drag) and mesh visibility.

#6

For very precise and sharp edged polygroups, after you create them you can run the Smooth By Groups brush (in the Brushes folder) over the polygroup borders at a low Z intensity setting.

#7

ok, many thanks for these helpful replies.

#8

Actually my last post should have read “…run the Smooth Groups brush (in the Brush>Smooth folder)…”

#9

I am creating various polygroups on my tool by using the mask brush and then Polygroups > create from masked

I then clear the mask and start masking out my next polygroupBut when I then select Polygroups > create from masked it creates the new polygroup ok, but deletes the old one!

How can I just gradually mask out each polygroup in turn so I end up with several polygroups on the model?

#10

http://docs.pixologic.com/reference-guide/tool/polymesh/polygroups/

#11

Thanks. But the reason I ask a question in the forums is because I haven’t been able to find the answer in the normal channels. The pixologic docs are pretty inadequate in general. This one certainly doesn’t answer my question. All it tells you is how to create one new polygroup in various ways, not how to create subsequent polygroups while preserving the existing ones.

#12

Don’t use this method Polygroups > create from masked.

If you want to create multiple polygroups, paint a mask and then hit Ctrl+W to convert the mask to a polygroup. Then paint another mask and hit Ctrl+W again to create another polygroup. Keep painting masks and hitting Ctrl+W as many times as you need to create as many polygroups as you need.

#13

I’m not too sure I fully understand your promblem Sophie. However, just masking an area and then using Ctrl+W will make a polygroup of the masked area. Mask the next area for polgrouping and Ctrl+W to make another polygroup. Repeat as often as you want.
You did remember to “Make Polymesh 3D first?”

#14

Whoops sorry Cad, you just beat me to it. :rolleyes:

#15

Aha! Thanks both.

My my mistake was that I assumed Ctrl-W was just a shortcut for “Polygroups > Group masked”