Paul, Research the differences between the concept of Keyframe and concept of Constraint. That should give you the basics to help you understand it better.
-- 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 3:56 PM To: [email protected] Subject: Re: path constrain Q (duh moment) 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. [https://mailfoogae.appspot.com/t?sender=pgriswold%40fusiondigitalproductions.com&type=zerocontent&guid=1c99bfe5-551f-47b9-b7ec-58d00adedee0]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 <[email protected]<mailto:[email protected]> <mailto:[email protected]<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:*[email protected]<mailto:[email protected]> <mailto:[email protected]<mailto:[email protected]>> [mailto:[email protected]<mailto:[email protected]> <mailto:[email protected]<mailto:[email protected]>>] *On Behalf Of *Paul Griswold *Sent:* Thursday, January 02, 2014 2:02 PM *To:* [email protected]<mailto:[email protected]> <mailto:[email protected]<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____
