If you constrain an object to a path and need to maintain a
controllable orientation you usually need to set an up vector object
that you can manipulate to maintain a consistent alignment.
If you want to control the roll manually, turn off the up vector check
box and keyframe by hand with the tangent axis still turned on.
On Thursday, January 02, 2014 3:55:46 PM, Paul Griswold wrote:
That's what I thought, but giving it a keyframe at frame zero gave me
unwanted roll along the path. I probably could fix it by keyframing
the roll. I just am trying to understand it better.
ᐧ
On Thu, Jan 2, 2014 at 3:51 PM, Eric Thivierge <[email protected]
<mailto:[email protected]>> wrote:
Objects evaluate keyframes, then constraints so the keyframe
should reset the orientation then the constraint will kick in and
reevaluate the orientation for you.
On Thursday, January 02, 2014 3:49:29 PM, Alan Fregtman wrote:
Because you didn't keyframe it?
Kinematics evaluate per frame and if you jump around too
violently in
your timeline you're gonna get inaccuracies unless you lock things
down a bit by using keys or strict upvectoring. Keys give it a
starting point from onto which to evaluate the constraints on.
On Thu, Jan 2, 2014 at 3:33 PM, Paul Griswold
<pgriswold@__fusiondigitalproductions.com
<mailto:[email protected]>
<mailto:pgriswold@__fusiondigitalproductions.com
<mailto:[email protected]>>> wrote:
Yes and no. I guess more than anything I don't understand
why, if
an object has a 0,0,0 rotation on frame 0, but path
constrained.
Why when you jump from a frame back to frame 0 does it
inherit
whatever rotation it had rather than return to 0,0,0?
ᐧ
On Thu, Jan 2, 2014 at 2:28 PM, Ponthieux, Joseph G.
(LARC-E1A)[LITES] <[email protected]
<mailto:[email protected]>
<mailto:[email protected]
<mailto:[email protected]>>> wrote:
Create a path(curve).____
__ __
Create a null.____
__ __
Path animate the null to the path, set it to tangent
and set
the up vector.____
__ __
Duplicate the null making it null1. Turn tangent off,
reset
the orientation to zero.____
__ __
Create a third null, position constrain it to follow
the first
null. Second is identical in position so ignore it.____
__ __
Constrain the third nulls orientation to the first
null.____
__ __
Constrain the third nulls orientation to the second
null. Open
the top orientation constraint of the third null and
adjust
the blend weight. You may need to use a rotation
offset(probably 180 in Y) to get the appropriate
blend.____
__ __
Use the blend weight to blend from the first null to the
second null orientation, keying it to adhere to the
tangent
null as needed.____
__ __
Constrain the object you want animated to the third
null. ____
__ __
Is that what you want?____
__ __
--____
Joey Ponthieux____
LaRC Information Technology Enhanced Services (LITES)____
Mymic Technical Services____
NASA Langley Research Center____
________________________________________________________
Opinions stated here-in are strictly those of the
author and
do not ____
represent the opinions of NASA or any other party.____
__ __
*From:*softimage-bounces@__listproc.autodesk.com
<mailto:[email protected]>
<mailto:softimage-bounces@__listproc.autodesk.com
<mailto:[email protected]>>
[mailto:softimage-bounces@__listproc.autodesk.com
<mailto:[email protected]>
<mailto:softimage-bounces@__listproc.autodesk.com
<mailto:[email protected]>>] *On Behalf
Of *Paul Griswold
*Sent:* Thursday, January 02, 2014 2:02 PM
*To:* [email protected].__com
<mailto:[email protected]>
<mailto:softimage@listproc.__autodesk.com
<mailto:[email protected]>>
*Subject:* path constrain Q (duh moment)____
__ __
When you path constrain an object & have it point
along the
path as well as maintain tangency, how do you get it
to reset
it's rotations back to 0,0,0 when you scrub back to
frame 1?____
__ __
Setting a key causes unwanted rotations & setting a
neutral
pose doesn't seem to work.____
__ __
I know this is a face-palm moment....____
__ __
-Paul____
__ __
ᐧ____
