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path constrain while keeping initial position
show user profile  digs
changed my nick, never liked the old one

I don't recall ever finding a way to do this - i have a nurbs curve with 100 points, I want to have 100 helpers spaced perfectly across the curve

that easy enough with snapshot - i get my helpers exactly over their points on the curve, but when I use path constraint, is shoots them all to 0% of the path - for some reason a curve with 100 points (or 99, etc) won't put the 50th point at 50%, so there's no good way of getting back to that perfect initial position

any thoughts?

(looks like a curve wont "make fit" over 100pts, i think that's what's messing with my percents... i need something close to 100 then)

- Mike Sawicki
read 458 times
9/16/2014 9:44:20 PM (last edit: 9/16/2014 10:09:40 PM)
show user profile  herfst1
Path constraint auto-makes a keyframe at 0 and 100. Delete the one at 100. Now shift drag your helper along a bit (as many times as you like/require). Say you made 5 in total, click on the second one and type "20" into the percentage (in the right-hand menu), select the third one and... last one will be "100."

As far as I know that's the only way to do it precisely.
read 456 times
9/16/2014 9:52:04 PM (last edit: 9/16/2014 9:52:27 PM)
show user profile  digs
I was affraid id have to shift drag them... looks like that's what its going to be
read 454 times
9/16/2014 10:08:58 PM (last edit: 9/16/2014 10:08:58 PM)
show user profile  digs
it seems like percents should work, but i need to have the helpers exactly on their points (i will be skinning the curve to these 100 helpers)

I'm trying to figure out how to get a nurbs curve with 101 points - i think that will work...

1 point at 0%, 1 point @ 100%, and 99 other points in the middle... that should be 101 points all with equal percents 0.o

or so you'd think?

- Mike Sawicki
read 449 times
9/16/2014 10:16:49 PM (last edit: 9/16/2014 10:16:49 PM)
show user profile  digs
here's a visual

The arrow controllers will control the overall shape up the underlying curve - ie, rotating those controllers will make a very wavy shape...

the orange global controller has three parameters, one of which (when translated to 0) will retract the yellow axis tripods backwards along the curve - these yellow helpers are the guys path constrained to the curve -

i need their position to be exactly where they are now when I apply the path constraint (which is exactly where the green box helpers are) --- the green box helpers and light blue ik goals will be position constrained to these yellow axis tripod helpers, so the entire rig can collapse in on itself

the only issue i have to figure out is a way of making the yellow helpers snap to the green helpers

- after applying a path constraint I can't seem to use snaps properly, and eyeballing it is sketchy, since I am position constraining green to yellow - if its not perfect, there will be a small jump when applying the position constraint

-edit- the post gods are cruel

change timeline to the number of points on the curve, apply path constraint to helper, scrub animation untill helper is in position, delete animation from helper
read 440 times
9/17/2014 1:55:01 AM (last edit: 9/17/2014 2:00:15 AM)
show user profile  herfst1
I'm not sure what you're doing, exactly, but if you need it to animate a wave motion you can rig up an ffd with a wave modifier above your skinning layer and animate the wave motion. It will mean having to parent the ffd to the rig (bit tricky, forget how I did that).
read 431 times
9/17/2014 3:48:11 AM (last edit: 9/17/2014 3:48:11 AM)
show user profile  digs
this is a catheter.. its got 4 sections (tubes) that need to retract/extend individually but follow a single path - it travels through an incision in the shoulder into some veins located in the heart - it just needs to be flexible enough to travel through all the different veins, and rotate together along the local x axis when the veins start branching, so it can make the tight turns

im getting some good animations now tho, could post up the vid when its all rendered
read 427 times
9/17/2014 5:36:23 AM (last edit: 9/17/2014 5:45:38 AM)
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