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 < [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]> 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:* [email protected] [mailto: >> [email protected]] *On Behalf Of *Paul Griswold >> *Sent:* Thursday, January 02, 2014 2:02 PM >> *To:* [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 >> > >
