unraveling internal rotaions of a curve

# 1 13-12-2011 , 04:42 PM

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Location: vienna

Posts: 1,095

Ahoi!

I have a question concerning the flipping of attached objects to a curve used as motion path.

I´d like to do a short movie with a camera rapidly moving along a complex model. therefor I made the geometry live and painted a curve on it. now when I attach the cameraGroup, or any other object to the motion path, alot of flipping occurs. (which makes it impossible to have a clean directional straight forward animation for the camera. not even speaking of using the option "bank")

question: is there any workflow to rebuild the curve or build it from scratch in a way so the attached object is animated along that curve without those sudden and random rotation flips? Best would be to have it oriented in a normal constraint style (defined by the models surface). is this even something which can be taken care of in the beginning by processing the curve itself, or does it need multiple curves and constraints for camera, camera_up and camera_aim...? or can a curve somehow get unraveled by rotating the CV´s? (I know thats not possible but how does a curve store this internal rotation of itself?)

any input/ideas would be great!

everything starts and ends in the right place at the right time.

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# 2 13-12-2011 , 05:06 PM

The thin red line
Join Date: Aug 2009

Location: England

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I used a locator above a mesh and perented it to the mesh then used that as a up vector on the motion path, the mesh did follow the motion path around without flipping..........dave

Edit:I just tryed it could not get it to work again

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Last edited by daverave; 13-12-2011 at 05:30 PM.

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# 3 13-12-2011 , 05:24 PM

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sound reasonable and I would do it that way if the model was somehow flat. but it has a cube shape (little more complex) and the camera goes around all sides. so there is no general "up". but I could animate the locator around the model as well, you are right. but I can´t use "bank" then, right? and what about the local Y-rotation (if Y is the up vector) it would need to be contrained as well. so this leads to an ell-constraints-solution.

but anyway - thank you for your idea!

any possibilities to fix the motion curve?

everything starts and ends in the right place at the right time.

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# 4 13-12-2011 , 05:37 PM

The thin red line
Join Date: Aug 2009

Location: England

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Some thing stange is going on with my motion path, I have change the vector to normal and its not flipping? Im sure I have tryed that before, Im getting old...........dave

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Last edited by daverave; 13-12-2011 at 05:40 PM.

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# 5 13-12-2011 , 06:49 PM

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hm.. I created some random surface, painted a curve and applied a camera. turns out that this time the motionThing behaves like it should. hm... seems I´m not able to recreate that error. this sucks user added image