How to use Back To the Center (Applied usage and usage of "Change the World-Aaxis" Mode)

Symmetrically editing object placed with tilt and return it to original location easily.
How to use Back to the Center plugin for Zbrush (Applied usage and usage of Change the World-Axis Mode).
It is described in Ver.1.0.1.
The basic usage is here.

(Table of contents)

Manual update history

2019/01/29 Manual release

Understanding the basics

First of all, please understand how to use basic usage.

Application 1 (Place cubes for locating in parts)

For example, in this way, we will place cubes and parts for locating in one subtool. Each way please freely.


This cube is referred to as "Reference Object"
(Hereinafter abbreviated as RO)

Please be sure to locate RO at the center of the part on the left and right. Be careful with the operation of Gizmo when placing. It is meaningless if it's not at center.

Hide by CTRL + SHIFT + double click immediately before BTC plugin execution

Since RO is hidden inside the part, in order to draw a transpose line, it is necessary to hide the visible part itself every time. Therefore, BTC set draw mode at the end of each Steps.
The raeson why, on Zbrush, except in draw mode, you can not use the non-display function by "CTRL + SHIFT + double click".

In addition, this non-display function is working when selecting the rectangle tool(SelectRect) or lasso tool (selectLasso). Lasso tool has a 2nd non-display function which hide only a poly loop. (Try selecting selectLasso and CTRL + SHIFT + click on a edge.)

But in this case it is inconvenient because you can hide only a poly loop unintentionally.

So, when executing the plug-in, the rectangle tool is automatically selected. (For this reason the window with "skip" button pops up at the initial startup.)

Other than that it is the same as the basics usage of BTC

In addition, the size of this RO is almost irrelevant to the accuracy of the rotation angle, so it is OK even if it is small or large.
I've tested the relationship between the size and rotation accuracy using object of size 0.01 and 10 ^ 8 (100 times magnification 4 times) larger one, but there were not enough difference for me.

Application 2 (Symmetrization of rotated parts without RO)

In order to do this,

  1. Originally symmetric mesh
  2. An axis is necessary at the center in the left-right direction on the mesh

These two conditions are mandatory. So, asymmetric objects such as made by sculptris pro mode can not be perfectly located symmetrically. Because it's not possible to draw the action line correctly in step 1 of BTC (In other words, it's not possible to select two symmetrical vertices).

Moreover, if there is no center axis in the left-right direction on the mesh, the center axis can not be moved to the origin because you can not select the centerd vertex correctly in step 3 of BTC .
So it is safe to make a mesh with a center line (centered edge) when making symmetrical objects. (For example, a dice with 24 polygons is safer than a dice with 6 polygons.)

Application 3 (When restart of Zbrush is required)

The BTC keeps the rotation and movement information in the memory. So, if Zbrush falls due to an unexpected error etc during modeling work after Step 3, the rotation and movement information will also be reset. Then you can not restore the location from the memory.

In order to avoid this tragedy, before the step 1 I have implemented a question window to make a backup of the subtool. If you have created a backup subtool at Step 1, you can restore the location after Zbrush restarted.

Restoration procedure

  1. Execute BTC to Step 3 with making backup subtool
  2. At this time, make a 2nd backup as a precaution
  3. The rotation and movement information is set in the memory by the procedure so far
  4. Select subtool that has been modeling work
  5. Execute Step 4
  6. The selectedd subtool is restored to the original location based on the information in the memory

You can return to the original location with this. The backup subtool is very important, so I've been careful about the implementation. For example, after you create the backup subtool and rename it, BTC hides the backup sabutool, reselect the original subtool and manipulate it so that you don't modify the backup itself.

I'd also considered implementing deleting function of the backup sub-tool after the restoration, but since there is a risk of erasing the erroneous subtool, it only displays a dialog message to delete it manually.

Working over several days is possible with Application 3

Using the technique of Application 3, you will be able to shut down the PC after saving ZPR. It's also possible to work over several days.

Change the World-Axis Mode

Change the World-Axis, abbreviated as CWA.
In the explanation in the basic usage and the applied usage, one subtool was rotated, moved to the origin, and returned to its original location after sculpting.
On the other hand, the function of CWA is to rotate the whole object coupled to one subtool and move it to the origin ( the world axis).

In this image the world axis is in the center of huge duck-like creatures. The image is directly in front.

The girl's face has been symmetrical by CWA, and the world axis is set near the forehead. The image is directly in front.
As all the objects are rotated and moved, there is no locational misalignment between the objects.


As a result, no misalignment occurs between the objects, so you can rotate it without worrying about the censoring error of rotation among the objcets .


In order to use CWA, it is necessary to combine all visible subtools into one.
If you use Transpose Master, you can easily combine and disassemble, but there are also caveats. (Described later)
The safest thing is to manually merge all the subtools, but since it's difficult to disassemble propely same as previous.
Again we recommend using Transpose Master.

Workflow of CWA

  1. Confirm that there are no hidden meshes in each displayed subtool (If included hidden meshes, unrecoverable error occurs when disassembling subtools on Transpose Master. Vertex mismatch error. See Subtool Master usage in Zbrush user guide .)
  2. (Or excute Del Hidden for all subtools in display state)
  3. BTC is applied and the origin of the world axis is set with your favorite location / angle
  4. Disassemble subtools in Transpose Master
  5. Sculpting working
  6. Combine subtools with Transpose Master
  7. Return it to the original location with BTC
  8. Disassemble subtools in Transpose Master

If there is a pedestal, you can return to the original location by repeating steps 1 to 3 twice


In CWA, if you prepare a pedestal in advance as shown in this figure, you can return it to its original location simply by rotating and moving it with BTC that does not assume restoration. As for what it says, instead of step 4 to restore, by using BTC Return the whole objects to original location by aligning the orientation and location of the pedestal to the world axis.

While BTC is based on one round trip, CWA can restore its location by applying BTC twice.

Benefits of CWA

  • CWA does not rotate single subtool by itself, the combined one subtool rotates, so the locational relationship of the subtools does not change. So CWA is effective when you want to keep their locational relationship perfectly.
  • Although the angle of the camera changes, you can sculpt symmetrically while watching the whole, so it is easy to balance parts to sculpt.
  • Since there is no need to keep rotational location information in memory, if ZPR preservation is done, there is no anxiety of Zbrush restarts, so it's easy mentally.

The disadvantage is depending on Transpose Master.

There may occur a problem with Transpose Master (Vertex mismatch error etc).
If you don't use Transpose Master, you can safely use CWA. But you need to conbine and disassemblethe necessary subtools manually.It's not very realistic.


Together with basic usage, we have introduced all the functions of Back To the Center.
I pridefully think it's a mistake-free plug-in that can be used conveniently.
Function expansion will be planned in the future. Please donate when you are satisfied.


I'm waiting for your donation.

End of document.

Below is my memo and don't mind.

今回の創作活動は約2時間30分(累積 約745時間)