View Full Version : rotate on axis not aligned with world

08-06-2007, 10:43 AM
I seem to have lost a portion of my brain -- I can't recall how to accomplish this.

I have an object that sits at about a 55 degree angle on the world pitch axis. It has an axle that extends straight out, and it rotates on this axle. I've placed the pivot point at the center of the axle, but none of the rotation axes are aligned with it, thus rotating it on that axle is pretty near impossible.

Any notions as to how to do this?

Screenshot below:


08-06-2007, 10:59 AM
Pictrix to the rescue.... v_roll is one that I know. A LW built in solution doesn't spring to mind, but I may have lost the same brain portion..

08-06-2007, 11:07 AM
Thanks for the quick response, but one little problem -- that's a modeler plugin (right?). I need to do this in layout. For animation purposes.

08-06-2007, 11:08 AM
ahhhh. In that case, i'll need to think again..

08-06-2007, 11:13 AM
Doesn't 'rotate pivot' work for you? It would be easier if you could do it like in the aforementioned v_roll and choose two points to align it with but it should work.

08-06-2007, 11:35 AM
Rotate pivot doesn't seem to be working the way I expect. I select the tool, rotate on the pitch axis 34 degrees, which brings the bank axis perpendicular to the axle. Then I switch to the rotate tool, to rotate the axle, and the axes are all screwed up. Furthermore LW reflects a 34 degree pitch rotation on the object -- I thought rotate pivot isn't supposed to affect that.

Example here:


08-06-2007, 11:43 AM
I found something that works, sort of. If I rotate the pivot pitch at a -56 degree angle, the heading axis winds up oriented properly when I get the rotate tool. Dreadfully counterintuitive, but it gets me where I need to be. So +34 looks like it should work, but -56 actually does. Go figure.

Thanks for your help cagey, and if anyone else wants to clear up the whys, I'm all ears.

08-06-2007, 11:52 AM
I can't download your clip, but if you require something more complicated than a simple change in the pivot angle then you are best parenting to a null. That way the objects whole pivot point will be rotated with it and you can use that in combination with the null to control all the settings.

08-06-2007, 12:01 PM
That's a pretty good idea. I'll give it a shot. Thanks.

08-06-2007, 03:03 PM
you can create a bone in modeler based on the two points of your axis.
Then set a weight map to 100 % on your object.
Back to layout, convert bones, set to weight map only, and rotate.

08-07-2007, 10:02 AM
Thanks jeanphi. i wound up using a combination of techniques (including your suggestion). All my joints work well enough now.