Need a little help with Flex and Flex motion

#1

Alright, I’ve done the reading in the manual and I am trying this strap up with a flex motion curve so I can animate it by hand unraveling. Everytime I try and add a flex motion curve, a flex curve, with bones etc. It never works. It always flips in crazy directions. I’ve looked at every possible alternative. My last attempt was just to do it with morphs but I realize its cheezy.

Can someone show me by rigging this simple strap with any of the above so I learn how it all works. In my opinion, its made too confusing where its not as obivous as adding bones is.

#2

Wish I had a better response, but the flex flips. Flexmotion too.

THe problem occurs when two nodes surpass a 90 degree angle to each other. One solution could be to have enough points so that you don’t surpass 90grad, or to have bones which are laid on to the spline and only receive position-along-curve info - not rotation.

Not nice, I know. pmG is aware of this and I believe they are working on a solution.

#3

THen how come the wormlier works?

#4

Have you tried moving a node 90 degrees past its neighbor?

#5

As I remerbered it you could set a null as a reference for the effect to partly solve the problem, I´ll check it tonight.

#6

Getting something to “wrap or unwrap” is very subjective…depends on what you want to see happen. As Geoff showed with the toothpaste example, sometimes it’s faster to just animate the bones.

However, so you can see what might be helpful, make a bone chain of about 11 bones. Create a new expession, use inherit root, set up the parameters, rotate, and for the two numerical values, use 1 and .04.

Then set some heading or pitch keys, and watch it work. Set three keys, allowing it to overshoot the end and come back. You can see if it’s helpful, as well as play with those parameters for different looks. You may also want to experiment with inherit end.

Best,
Rick

#7

Here is an example of how to do it using a simple flex curve. I hope this is kind of animation you were looking foor. Strap rolling into itself.

Cheers,

boris

#8

this might help

#9

borisgoreta2000, when I try to dl your example it says the zip file is invalid.

#10

hi borisgoreta2000, your file reminded me that the curve flipping problem only occurs on the vertical y direction of the curve. No problem with the side overlap, so you could just rotate your flex curve on a master null.
Cool!

#11

Leebert - the file is actually a rar file. Rename the zip extension to rar. CGTalk doesn’t allow rar uploads.

#12

dobermunk - here is the same animation but curling in y direction so it is possible to do that without flipping too. You just have to go to setup->curve->curve and set type from vector to rail. Rail works much better. Cheers

P.S. Attached file is actually a .rar file

#13

Borisgoreta2000 - wow, thanks. Just checked it in the docs - don’t knopw how we’ve missed this! The spine in Marek’s rig can be done much simpler, me thinks. Thanks!

#14

great stuff…

anyone know how to control the ‘twist’ of a flex motion curve? for example on a long neck i need the ability to tilt the head to the side and want the twist to flow into the neck.

thanks
steve

#15

You could override (or additive) their bank values with the head object… reducing the amount down the neck.

#16

I’ll tell you waht I’m trying to accomplish I want this to unravel towards the camera in a spiral motion. All the help you’ve given so far is much appreciated.

#17

Just as something else to think about…there’s the old trick of morping the object in space thru te bones…

setting the bone effect with the spiral you want, and then running a morph between two positions for the object above and below the bone placement.

Not as much control as you may want if it has to do other things, but just another “idea”.

Best,
Rick

#18

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