Franck Thomas (fthomas)

2 answers · asked · Lesson: Rivet Walk Cycle · Course: Blender Animation Bootcamp

Torso Rotation as Quaternion

Hi Wayne,

Is there any specific reason that the Torso controller is set to quaternion?

I remember you talked about quaternion usage to avoid the infamous Gimbal Lock which can happen with euler angles but I don't think it could be the case here right?

Also is it best practice to animate the rotation only on the Chest / Hips and animate only the translation on the Torso or we don't care?

And last question (for now), I think the Torso here is commonly the Pelvis bone is game engine, so to export a walk/run cycle like this (with perfect synchronize foot/translation to avoid sliding foot) is it better to animate the forward translation on the pelvis or on the root?



  • crew

    I like to set Quaternion rotation mode on all the controls that move on 3 axes (with a few exceptions)

    Yes you can get gimbal lock on the Torso, in fact it is really common if the character has to move around the scene in more than 1 main direction.  (the issue is when the middle axis rotates near 90 degrees - eg in XYZ, when the Y rotates 90, In ZXY it's when the X rotates 90 ect)

    The torso rotation is kind of like a master rotation for the entire torso whereas the chest/hips and spine are local (if that makes sense)

    In game rigs you will find a Torso control (sometimes called COG for centre of gravity) AND a pelvis (or hips) control.  This is so the whole torso doesn't rotate when you need to move just the hips.

    If it's an inplace walk.  Animate the root control moving forward then export.

    If it's a translating walk, leave the root alone and just export 1 cycle.

    Hope that helps.

  • "Copy that, HQ. Returning to Blender. "

    Thanks for the answer Wayne, I've got more questions but it can wait until I finished the Rivet walk cycle.