It might be easier to just have an upvector null that you animate or place in a convenient position.
On Thu, Jan 2, 2014 at 3:55 PM, Paul Griswold < pgrisw...@fusiondigitalproductions.com> 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 <ethivie...@hybride.com>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 >>> <pgrisw...@fusiondigitalproductions.com >>> <mailto:pgrisw...@fusiondigitalproductions.com>> 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] <j.ponthi...@nasa.gov >>> <mailto:j.ponthi...@nasa.gov>> 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-boun...@listproc.autodesk.com >>> <mailto:softimage-boun...@listproc.autodesk.com> >>> [mailto:softimage-boun...@listproc.autodesk.com >>> <mailto:softimage-boun...@listproc.autodesk.com>] *On Behalf >>> Of *Paul Griswold >>> *Sent:* Thursday, January 02, 2014 2:02 PM >>> *To:* softimage@listproc.autodesk.com >>> <mailto:softimage@listproc.autodesk.com> >>> *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____ >>> >>> >>> >>> >> >
