ZBrushCentral

Manipulating an entire Zspheres rig?

ZBrush Usage Questions
#1

First, sorry for the cross post in the general forum. New to this, and only after posting did I realize this was a better place for my post.

I need to scale an entire zsphere rig to fit an imported reference obj-model. According to all info I came across I should be able to scale, rotate and move the root zsphere and it’s children will transpose accordingly. In my case I can’t seem to achieve this at all. Any manipulation of the root zsphere is restricted to this one alone. Regardless if I click inside or outside the central circle. What fundamental thing am I missing here?

The only way I was able to scale the entire zsphere rig was to use deformations. But once the rigl is meshed and exported it comes in at it’s original size in 3ds Max. So I guess this is another question I have. Is there no way of permanenting a scaling by deformation, so that once you hit “unify”, the model will not revert to it’s original size?

Thomas

#2

The root zsphere and the links that lie between the root and child zspheres behave differently when scaling in edit mode. You are right to use the Tool > Deformations palette instead. But when you hit Unify you are basically back to square one. Why are you pressing Unify?

You can check the actual size of your tool in zbrush by looking at the Tool > Preview > Object Preview icon.

#3

Well, I press unify in order to get a reference of how big my Zsphere rig actually is. My objective was to resize the rig to fit with an imported reference object that was originally modeled in 3ds Max. Resizing the Zsphere rig by deformations is just a visual rescaling, not an actual one it seems. Because when I turn my rig into a mesh and export it into 3ds Max, the Zbrush object comes in ridiculously small in relation to the object I wanted to fit it to.

Surely there has to be a way to truly re-scale a Zphere rig?

T

#4

I see what you mean. I believe the problem is the Tool > Export > Scale setting which will most likely be a default value for zsphere generated geometry. Resizing by deformations should always affect the size of exported geometry.

There are various ways to go about fixing this but try the following :

  • Import your 3DS Max mesh as a new tool by selecting a non-polymesh tool and pressing Tool > Import.

  • Tool > Subtool > Append your zsphere rig to the 3DS Max tool and apply deformations to resize it.

  • If exporting now does not give you the correct scale in 3DS Max try Tool > Make Polymesh3D after you have resized the zsphere rig and then append the generated polymesh tool to the 3DS Max tool. The Tool > Export > Scale setting should be the same for the 3DS Max subtool and the appended zsphere polymesh subtool.

#5

Ok, will try this. But what of the possibility of just manipulating the root Zsphere? I came across a couple of references to this in other forum posts. Was this a former feature that was somehow redefined as a bug and removed in later versions of Zbrush?:confused:

#6

Yes, you were right that appending the Zspheres as a subtool to the imported object sorted out the scaling discrepancies upon export.

But then I get another surprise. My imported reference object from Max is a chair facing the front viewport in Max, standing on the floor in the Max world. Let’s say I want to model a person sitting in this chair. I import the object from Max. Create a root Zsphere, scale it to a reasonable size and place it on the chair. Problem is, the upside of the Zsphere is facing the wrong direction. The lighter red part of the Zphere is pointing straight into the back of the chair. In order to be able to use symmetrical creation of further Zspheres, I need to rotate the root Zsphere. But it cannot be done. I tried the transpose method aswell as the deformations method. These methods will only serve to move the Zsphere around in one way or the other. No rotation. Surely a bug, or what were the developers thinking?

I find myself loving Zbrush more and more, but I need to be able to use it in conjunction with other software without serious workarounds for this and that…

T

#7

Rotating a root zsphere with deformations or the Tool > Preview > Object Preview icon does change the orientation of the root zsphere. It is just that it is not indicated visually. If you preview the adaptive skin you can see it has an effect.

But in your case it is not necessary to rotate the root zsphere. You could just use a different axis for your symmetry. ‘X’ activates symmetry which defaults to the X axis, just change it to Y or Z in the Transform palette.

You may be able to change the way imported geometry is oriented in ZBrush. Preferences > ImportExport > iSwitchYZ and eSwitchYZ (import and export) should make your 3DS Max geometry import / export to and from ZBrush with the correct orientation. It is probably best to do a quick test.

#8

Unfortunately, none of the symmetry axis combinations worked in this particular case. I already tried.

Also tried the iSwitchYZ option. It indeed orients the imported object correctly, but curiously the normals will be flipped regardless of if I check the iNormalsFlip or not. A bug probably. But I can check the double sided display option and scale and position my root Zsphere and model my Zsphere rig. However, once I export the Subtools back into Max via subtool master, the Zsphere rig comes in with the normals flipped into Max.

But I believe I found the solution. THe best method so far has been to export and import in Max using GwObj-exporter using the Zbrush preset. No normal flipping or unexpected side effects as opposed to using Zbrush’s various switching options. Once you’re done modelling your Zspheres in Zbrush, you’ll have to use a plugin like Subtool Master to get around the scaling problems. And you indeed have to make sure to have chosen the imported subtool as the active subtool instead of any subtool that was created in Zbrush. Otherwize the scales will be all wrong once you import into Max.

The only downside to this is that you can’t limit your export to one specific subtool in Zbrush, as subtool Master will export all subtools. So much hassle. Makes me wish for GoZ for Max:p

T