Resetting transformations puts pivot below zero

[carrZ84BC]

I have an issue with several object in my scene where the pivots of the objects gets reset to below zero on the vertical axis.  This is a screenshot of the problem, I "Reset Transformations" before taking the shot.

The  rotor and tyre also have the problem, but the rims don't. I have reset all the tool settings and made sure they are set to world.  I have tried baking the pivots and freezing again before resetting.  I have also deleted history and tried restarting the program.  Googling the problem hasn't come up with any results for the same thing, I tried several different searches.

Any help would be appreciated.

[brentmc]

Hi,

Reset transformations does not zero out everything in the transform matrix.

Open up the attribute editor and see what the local pivot values are set to for your object:

 

With the attribute editor open you will be able to see effects of the various Reset/Freeze/Bake commands on your object.

Reset Transformation - zeros out the scale/rotate/transform fields (pivots are preserved)

Freeze Transformation - applies the current transform to the geometry and resets the transform fields (pivots are preserved)

Bake Pivots - transfers the pivot transformation into the translate field and zeros out the pivot values (you can then reset/freeze the translation as required) 

--

Brent

[carrZ84BC]

Thank you very much, this was being rather problematic for me.

[carrZ84BC]

I did a bit more working on this and after removing the vertical adjustment in the local pivot, it automatically transfer the value to world pivot and vise-versa.  Regardsless of which one the value is in, when resetting transformations, it goes to world.  How do I zero them both out?

[carrZ84BC]

This is what I get after I reset pivot.

I need the pivot to be at 0,0,0 for the program I am using the model for or it can render it in the offset position.

[brentmc]

Bake Pivots followed by Reset Transformations should zero out the pivots?

Note: Reset Pivot will set the pivots to the center of the geometry, not zero them out.

--

Brent

[carrZ84BC]

I tried that but it doesn't work.  This is the outcome of each action in succession.

Centre

Bake

Freeze

reset

I have this problem with several objects in my scene and have no idea how it happened.  I will be exporting these to be used in a game I am modding to try and learn stuff and require the pivot to be at 0,0,0 for it to render correctly.

Your help is greatly appreciated.  Thanks.

[brentmc]

Hi,

The local and world pivots are not actual attributes but fields that use the xform command to display the pivot values in object-space and world-space respectively.

If you really want to zero out the pivot channels you can use the xform command. (e.g. see the  -zeroTransformPivots flag)

https://help.autodesk.com/cloudhelp/2020/ENU/Maya-Tech-Docs/Commands/xform.html

Would probably need a (partial) scene to help diagnose this further.

--

Brent

[carrZ84BC]

I tried the xform and it just does the same thing from what I can see.

If you are willing to take a look and see what I have done wrong, it would be greatly appreciated.  I am only a novice user with no training so there are probalby many "non ideal" things I have done and some messy aspects of the scene.  Hopefully it isn't too bad.

[brentmc · Accepted solution]

Hi,

Transforms are relative to their parent (group) transforms.

Looking at the scene structure in the Outliner I can see that there is a Z translation on the Wheel_Tyres transform of -6.322 which is why your centers are below the origin.

Also note that the Wheels_Tyres is a little strange in that all the transforms are centered on the world origin.

This would make it hard to animate the wheels around their centers while also moving the whole car so you should probably look at some videos like the one I found below to understand how grouping is used in animation. 

https://www.youtube.com/watch?v=bcI2Pif_Avo

Also, maybe look at something like a basic solar system tutorial where groups are used to allow planets to rotate on their axes while also rotating around the sun. 

--

Brent

[carrZ84BC]

You sir are a legend, I checked the groups and was looking at the local pivot numbers and must have overlooked that one.  

For the game engine I am using, anything that rotates indepentantly requires a centered pivot, everything else that moves as a group requires a 0,0,0 pivot.  Some of them in the scene may have been different from the finished project as I was trying to sort out the issue.

I will have a look at the video and do more research as I do need to learn about animation, more specifically bones and movement so I can set the parameters for the drivers arms.

Thanks again for your help, I was pulling my hair out trying to find it.