دانلود کتاب به همراه DVD فایل ها و تمرین آموزشی نرم افزار ZBrush به زبان فارسی ZBrush Organizing geometry using polygroups

آموزش گام به گام ZBrush  به زبان فارسی

00:01:36  So I'm going to hold Ctrl+Shift, drag  a selection here, let go of the Shift

00:01:43  key, this polygon will disappear.

00:01:48  You can see why it's a good idea to  practice using the Ctrl and Shift selection

00:01:52  technique, because it is something  that you will do fairly frequently.

00:01:56  Just this little part of the upper lip  is still visible. So Ctrl+Shift, release

00:02:02  the Shift key. There we go.

00:02:04  Once again, Ctrl+Shift, drag around  selection, release the Shift key, and let

00:02:13  go. One more time right there. Then  these polygons over here; Ctrl+Shift, drag

00:02:21  around, release the Shift key. These,  Ctrl+Shift release the Shift key, and

00:02:31  there we go, we have our lower lip area.

00:02:35  I'm just going to do a couple more  over here, and then again down here,

00:02:40  Ctrl+Shift, release the Shift key, and  let go. So now what I can do is I can go

00:02:45  to my Masking palette right here, its  part of the Tool palette, to load it right

00:02:51  here. Masking is available right  here. Do Mask All; I'm going to

00:02:56  Ctrl+Shift+Click so I can see the rest  of the model. Press the F key so I can

00:03:02  zoom out, and do Invert.

00:03:06  Now I have this area available for  working, it's been isolated, and I have the

00:03:11  rest of the model is masked,  so it won't be changed.

00:03:14  For example, if I make my changes to  my lower lip and then I clear the mask,

00:03:18  and then I suddenly realize, oh, I  would like to make some more changes to that

00:03:22  lower lip. Well, now I have to repeat  that entire process again, what I just

00:03:27  went through, to make that selection,  and that can get very, very tedious.

00:03:32  The solution to this problem is to use  Polygroups. When you create a Polygroup,

00:03:36  you organize part of the model, and  that organized group is always there for

00:03:41  you, available to isolate or to hide as needed.

00:03:45  To create the Polygroup you start by  using the same technique. I'm going to

00:03:49  zoom in again, and let's create a  Polygroup just for the mouth area.

00:03:53  So I'm going to hold Ctrl+Shift and  drag my selection just around the mouth

00:03:58  area here, let go of the pen from the  tablet. Now I have the mouth isolated. I

00:04:06  just go to the Polygroups subpalette,  which is right here, beneath Masking. I

00:04:11  will hide some of these so  it's a little bit easier to see.

00:04:14  So I will go into Polygroups, and I  just do Group Visible, and you will see the

00:04:20  color is changed. This doesn't  actually change the color on the model; if I

00:04:24  unhide the rest of the model you will  see what's going on here. I will press

00:04:27  Ctrl+Shift+Click on the canvas, and there we go.

00:04:30  If I turn Frame off, you see the color  is still all the same. When I turn Frame

00:04:36  on, the color coding lets me know which  parts of the model are in which groups.

00:04:42  So if I want to isolate the mouth  again, I don't have to repeat that entire

00:04:46  process, all I have to do is Ctrl+ Shift and Click, and now the mouth is

00:04:52  isolated. If I Ctrl+Shift and Click on  it again, now I have everything that's

00:04:56  not in the group visible and the group  is invisible. If I Ctrl+Shift, Click on

00:05:01  the canvas, back to having  both of my groups visible.

00:05:06  I'm going to go through the process  one more time, maybe we will do the eye

00:05:11  area here. So Ctrl+Shift, start to make  my selection on the canvas, and let go.

00:05:19  Now I just have my eyes visible here.  That flipping is just a quirk of ZBrush.

00:05:25  It happens on pretty much all  computers. I'm going to press Group Visible.

00:05:32  Now, I Ctrl+Shift, Click on the canvas,  now I have three groups. I have the

00:05:37  mouth area and I have the eye area.

00:05:39  If I want this to be isolated, I  just Ctrl+Shift, and there we go.

00:05:45  Ctrl+Shift+Click again, it's inverted.  Ctrl+Shift+Click on the canvas, I have

00:05:53  everything available.

00:05:55  Now, any polygon that's part of the  model can only be in one group at one time.

00:05:59  In other words, if I decide to make a  group for the nose; Ctrl+Shift drag this

00:06:05  area here, and I will get some of this  group too, and then I'm going to let go,

00:06:09  so just have the nose area. So I have  this area and these two areas, which are

00:06:14  in three different groups. If I do  Group Visible, a new color is applied. I

00:06:19  Ctrl+Shift, you can see I have three  groups. It's a little bit more obvious to

00:06:25  change the color. So I Ctrl+Shift +Click there, do Group Visible.

00:06:31  So what I'm showing you right now is  every time I press Group Visible you see

00:06:35  the nose changing colors. This is a  good technique if you decide that you don't

00:06:39  like the color that's been assigned to  your group. One reason why you might not

00:06:43  like the color assigned to the group  is that it's too similar to the other

00:06:47  Polygroups. But now it's  a little bit more obvious.

00:06:49  I have this fuschia group, this purple  group, and this green group, and sort of

00:06:54  the orangish golden group, but you  will notice what has happened is, these

00:06:58  polygons that were part of the green  group have now been overwritten with the

00:07:02  fuschia group. So polygons can only  be part of one polygroup at a time.

00:07:11  When I'm working on the face and  something that I'm going to be creating,

00:07:14  facial expressions for instance, if I'm  making morphed targets for an animation

00:07:18  program, such as Maya from a face model,  I will usually start by organizing the

00:07:23  entire model into polygroups based on  what I know I'm going to be working with

00:07:27  a lot. So I will isolate the upper lip  from the lower lip, I will isolate each

00:07:32  eye into its own polygroup, parts of  the cheek, the chin, the eyebrows, and so

00:07:37  on and so forth.

00:07:38  Then I will save the model, because  the polygroups are saved with the model.

00:07:41  Every time I load this model I will see  the same polygroups. Then I can quickly

00:07:45  go in and isolate those sections. So  if I want to work on the eyebrows, I can

00:07:50  just click on that. I just Ctrl+Shift+ Click on part of the polygroup. Maybe I

00:07:56  will do Mask All. Ctrl+Shift+Click on  the canvas, invert the mask. Now, I can

00:08:04  just work on this area without  worrying about changing any of the other parts

00:08:09  of the model. It's just  this part that's been isolated.

00:08:12  Polygroups persist on different  Subdivision Levels. So I'm going to clear the

00:08:17  mask here and just increase the  Subdivision Level by going to the Geometry

00:08:22  palette and moving the slider up. You  can see, Polygroups are still there.

00:08:27  A lot of power and a lot of options  there for working with the models. The main

00:08:39  purpose of Polygroups is just to  organize your model so that you can reduce the

00:08:42  amount of selecting and masking on  the same parts of the model. I would

00:08:47  recommend taking some time to practice  with the Selection tools and practice  organizing a model into Polygroups,  you will find it in the long run, it's a  huge time saver.