6 Replies Latest reply on Nov 15, 2010 8:26 PM by aefilter

# X-rotation bug?

When doing a 3-d rotation is appears that the x-rotation is on the global X-axis, not the layers axis while the other two rotate the layer's axes. The easiest example of this is to rotate a shape or solid on the Y-axis 90 degrees then rotate the other two axes. The X and Z axes appear to merge into one.

Is there a work around for this, aside from redoing my whole projects using the orientation?

A zipped project can be found here:

http://www.zeveisenberg.com/dropbox/Rotation.aep.zip

• ###### 1. Re: X-rotation bug?

I was able to repro this behavior but only if i do the steps in the same order as you. If i rotate x or z first, and then Y, everything works as expected. Very weird indeed.

• ###### 2. Re: X-rotation bug?

A 2D layer always rotates around what becomes the Z layer when the layer becomes 3D. X and Y rotation (not orientation) is always around the X and Y axis of the world while the Z axis and therefore rotation in Z remains perpendicular to the XY plane. If you take a close look at what is really going on when you rotate you'll discover that rotating Y to 90º doesn't really cause X and Z to merge, it's just point where X rotation according to the world lines up with the Z axis of the layer.  This is the difference between orientation and rotation.

You'll clearly see that the layer rotates relative to the world and not relative to the layer when you try other angles.

I've attached some arrows to your comp so you can see the effect. This isn't a bug, it's the way the 3D world was designed.

The only way to use rotation properties to animate rotation relative to the layer and not to the world is to press the W key, make sure local axis mode is selected, then grab only the X or Y axis of the layer and drag. You'll notice that when you grab X or Y all of the rotation properties change, but when you grab the Z axis only those values change.

• ###### 3. Re: X-rotation bug?

As Rick said, perfectly normal behavior. The rotation axes just incidentally are perfectly aligned in such a case, eliminating the difference between local coordinates and world coordinates. Since AE uses a fixed rotation order, you will have to use Null objects and parenting to separate the individual rotation planes, if it's really a problem. Or you could of course write your own rotation expressions, of course. You can get some of that cleared out by watching this little beauty here:

http://www.guerrillacg.org/home/3d-rigging/the-rotation-problem

It's for 3D programs, but the issue is pretty much the same.

Mylenium

• ###### 4. Re: X-rotation bug?

Rick, I've taken the liberty to add a comment on this on the help files based on your post. Hope you don't mind.

Mylenium

• ###### 5. Re: X-rotation bug?

Don't mind a bit Mylenium. I've had a half written tutorial on animating 3D layers in AE on the  back burner for months. I guess it's time to finish it. It covers solutions to this and other common problems.

• ###### 6. Re: X-rotation bug?

Rick, did you ever post any of those 3D tutorials?

Rich