My object flips along my motion path

[killingtool]

Hello. I'm attempting to do the 3D smoking tutorial at http://www.highend3d.com/maya/tutorials/smoking.3d and ran into a problem I cannot seem to solve.

I've got an object which is my cigarette butt.
I've got a path which is the word "Maya" spelled out in cursive.

When I attempt to attach my object to the path, it attaches, but when I animate it, the cigarette flips back and forth between the front and back sides of my path. I want it to stay on one side of my path (the back side).

In the manual it says:

"World Up Object - Specifies the object the world up vector tries to align with if World Up Type is set to Object Up or Object Rotation Up. For example, you could specify the world up object as a locator that you can rotate as needed to prevent any sudden flipping problems as the object moves along the curve."

This speaks somewhat to my problem, so I've tried using the "Obect Up" option, but haven't been successful.

I've tried every combination in the edit box (except for the correct one supposedly), but or reference I'm currently using the following settings:

Follow: Yes
Front Axis: Z
Up Axis: Y
World Up Type: Vector
World Up Vector: 0 1 0

Any help would be appreciated.

[gmask]

To quote someone else.." Ive experienced thiskind of behaivor many times, sometimes the trick is not to cross any of the world axises(or sometimes local) in your sceneas this would cause some flipping problems, especially avoiud the origin (something to do with the maths involved)."

In otherwords try moving you curve so that it is one quadrant and not crossing the center of the world origin.

g

[stevesayer]

Technically, since we're working in 3D space, it would be an 'octant' instead of a 'quadrant.'

Sorry, gmask, just a little tongue-in-cheek ribbing... thanks for all your input here on the boards; I've been watching the past few days and you've been a real help to a lot of people! --Keep it up...

Cheers,

-Steve

[gmask]

Technically, since we're working in 3D space, it would be an 'octant' instead of a 'quadrant.'

Good point.. of course if the animation path is coplanar and perpendicular then it's still a quadrant which it sounds like his animation may very well be. Don't hear too many people throwing around octant in fact I think this is the first mention of here ever

...from my tests this is mostly a problem when you cross the origin of the the up axis.. in most cases the y and this will occur even if the path is coplanar and perpendicular.

g

[killingtool]

In reply to:
In otherwords try moving you curve so that it is one quadrant and not crossing the center of the world origin.

I tried your suggestion, and unfortunately it did not solve the problem. I posted a copy of the problem.mb file on my website at: http://www.zaske.com/problem.mb in case anyone is interested in seeing my problem.

I'm sure it's something brain-dead simple, as I'm just starting with Maya.

Well back to modeling.

[gmask]

I had a chacne to take a look at your file.. If you just want the cig to "trace" the curve then turn off follow and it won't flip.