ZBrushCentral

Is it possible to Reassign Axes in an .obj Model?

ZBrush Usage Questions
#1

Hi,

Let me start by providing an intro/explanation…

I am an absolutely brand new newbie to ZBrush. I have watched Meats Meier’s “Introduction to ZBrush”, and I have spent a lot of time reading through the ZBrushCentral forums.

What a cool piece of software ZBrush is! And what a shame that I am in NO WAY an artist…

I am working for a small company that has developed software for airports that allows the airport to view real-time/historical flights in an animated 3D environment over a map of the area surrounding the airport. It’s kind of like taking Google Earth and adding 3D airplane models (only the mapping resolution is better than you get on Google Earth) that are flown in the environment based on flight track data for the airport. The software uses OpenGL to draw the planes.

They have a few planes that are .obj models, and they want to increase their “fleet” of models and create decent looking airline specific “skins”/“textures”.

We recently purchased an .obj model from a guy on the internet to experiment with creating “skins”/“textures”, but the model’s axis assignments appear to be different from the other models we have. It seems that this model’s Y & Z axes are swapped when compared to the other models we have.

I can change the initial position of the model in ZBrush by importing the .obj and using Tool > Preview then changing the position, storing and exporting the model. But I haven’t found a way to reassign or “swap” axes used in the model in ZBrush.

Is there a way in ZBrush that I can reassign or swap the axis assignments used in an .obj?

Thanks in advance for any help with this,
Rob

#2

Actually, what you described with the Tool>Preview does change the axis. All you have to do is export the model at that point.

Alternatively, since you know which axes are involved you can also modify the Preferences>Importexportoptions to tell ZBrush how to flip the axes when you export a model.

#3

Also, a very simple, interactive way to permanently change model’s axes is to use the TOOL>Deformation>Rotate command… first you select the axis you want to rotate around (x,y or z), then click the slider, type in 90 (or -90 depending) and press Enter.

Sven

#4

Yep! This is actually exactly the same as using the Preview followed by the Store button. I didn’t mention it because you normally have to have the Preview open anyway so that you can see which axis to have active in the Deformation menu. :wink: But you’re absolutely right.

#5

Thank you both for the replies…

I have spent an hour or so (so far) trying the different methods you pointed out. I may be completely wrong, but it still appears that Tool>Preview and Tool>Deformation>Rotate modify the position of the model along the axis being modified. These steps do not seem to “reassign” the axes.

However, the Preferences>Importexport>iSwitchYZ and eSwitchYZ do seem like they may address the very issue I’m dealing with. The contextual help on these items explains that ZBrush may assign Y & Z axes differently from other programs.

I will continue to work with these settings and see if I can get something to work.

Thanks again for the responses! I’ll post an update here after I spend some more time working on it.

Rob

#6

The preview changes position only if you move the cross hair in the middle. If you don’t move the cross hair, it changes orientation. When you press Store, the new orientation becomes permanent. No movement involved.

Rotate does the same thing without having to press Store.

Look at it this way: The preview window shows the model’s XYZ axes (Z faces the camera). When you use the Rotate deformation or just twiddle the preview and press Store, those axes change. This is exactly what you want.