I assume you are not applying an up vector and the object is demonstrating a “roll” when setting back to frame 0? In other words its obeying the tangency expected at Frame 0 but not the roll, is that correct?
If that’s the case its because it is acting like a “position” constraint at a point along the curve which is also inheriting curve tangency as a constraint also. If no up vector is applied it will attempt to inherit as much of the orientation as possible because it’s a constraint and not a keyframe. If it was an explicit keyframe it would do what you expect, else you need an up vector to control the rotation. When the object was at 0,0,0 at Frame 0 it is assumed that there was no orientation keyframe, at least that is the assumption with available information. If it just happens to be 0,0,0 because that was its creation state or whatever, it does not know what to return to if it was not keyframed or some other constraint is set to control the roll. -- 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 3:33 PM To: [email protected] Subject: Re: path constrain Q (duh moment) 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? [https://mailfoogae.appspot.com/t?sender=pgriswold%40fusiondigitalproductions.com&type=zerocontent&guid=32127dcd-8809-4e8a-802b-b5226d0875ae]ᐧ On Thu, Jan 2, 2014 at 2:28 PM, Ponthieux, Joseph G. (LARC-E1A)[LITES] <[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]>] On Behalf Of Paul Griswold Sent: Thursday, January 02, 2014 2:02 PM To: [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 [https://mailfoogae.appspot.com/[email protected]&type=zerocontent&guid=be00b853-9de5-4b01-accd-845f578f950d]ᐧ
