Prop/Accessory Rigs
Sometimes you have a character or item design that does not lend itself to pre-scripting. Compiling some solutions to different problems that do not fit well under the 'modular' hat as they involve a specialized solution not likely to be used often. Meant to be a ref. sheet and jumping off point for finding a solution
Book
book rig(redesigndavid)
this rig uses 'blendWeighted' nodes to blend page joint values between the middle and the two sides.
for the page deformation, it uses a network of bound lattices ultimately shaping a master lattice that shapes the page. It's a neat system that allows for a lot of flexibility.
Fish
Auto-swim fish rig (Zeth Willie)
Noise
Ribbon
Procedural Ribbon Tutorial (J-H. Paulsen)
Anyone got any particular tips for the best way to animate a ribbon tying from two loose ends?
We do ribbons constantly..
I tend to use an curve with joints constrained along it with a matching
up vector curve that is then controlled by floating joints that can either
be FK/ spline IK/ or just translated willy nilly .
then bind a lattice to the curveConstrainedJoints and push my geo thru the
lattice. ( generally translate) as using the partial growth on extrusions
or lofts tends to do wacky things to uvs.
for an upcoming job right now I've automated the process based on animator
created curves with just flowPath for previs. then converted afterwards
into rigs. ( using a secondary curve to get the up vector ) ( its not
aired yet. so I can't reveal it )
I sometimes use flowPath motion paths, but I always give it an up vector
curve
(S. Mann)
My method was to create a curve and extrude the ribbon along it.Using a duplicate of the first curve, I made some blend shapes of the ribbon's path, then just animated between them.
When the bow pulls tight I just keyed the envelope of a high res lattice that just added in those little creases.
I did try motion paths/flow object but found maya didn't have a great way of interpreting the up vector around some of the tight loops. Unlike softimage that has a decent method to straightening these out.
Rather than blend shapes it would be possible to add cluster controls the cvs of the curve and animate that way, just depends on the time you have.
(T. Cosgrove)
Our lead Animation artist hates doing ribbons, because its a lot of brute
force.. Think animating points on a curve .
but he's also really good at it.
It's a super pain to edit afterwards
straight ahead works best.
hide things where you can ( if you can )
We've found often that you need to more imply a tie and the center can be
a separate piece of ribbon to lock it down, Often when we do physically
accurate knots ( when asked to do so ) .. It's not as interesting or
elegant.
one thing that is super cool , but you need to do some dynamic baking to
get results is the "lock curve" function.. It's awesome.. but , It's not
easy to work with.. you can't deform it, and keying it doesn't really work
, but. you can match controls, or points to a locked curve, and key those
(S. Mann)
I had to make something similar a couple years ago. You could attach yor
geometry to a motion path and then convert it to ncloth - depending on the
level of detail and deformations you need, could be overkill - . I still
have this cgtalk post on my bookmarks, take a look at Duncan's posts and
the scene file he attached.
http://forums.cgsociety.org/showthread.php?t=676298
I don't have my scene right now, but I'm pretty shure I also created
clusters in the cv curve points for an additional layer of control, and
used a Lattice foor tightening the knot.
That being said, I't wasn't a macro/hyper/close up shot, so It was a little
bit rough at the edges. When I get home I'll check my files
(E. Guisandes)
I was going to come and echo pretty much exactly the same thing as Mr Mann
said. We actually do it so often that we created a plugin for the setup
since it can be a pain for feedback and you can automate adding/removing
cvs/joints to the curve easier that way. You can also control the joints
with a spline IK with offset enabled in order to some mass conservation but
I'd recommend a more hearty scripted approach then that if you really want
to do it right.
Or just do the extrude along curve+lattice...it almost always turns out to
be faster and easier to make a quick rig the animator just creates based on
the shot than some really amazing beautiful setup for a ribbon tying when
you can spend your time rigging more interesting things ;).
(A. Weber)
How do you setup an up vector curve? I've tried to do this before and
failed. I would assume it's an expression; for every u value on curve1,
point tangent to same u value of curve 2, by finding vector between them.
R
No scripting necessary.
Duplicate your current curve
Attach a transform to it via motion path
Create the object you want to animate to the original curve with it's up vector set to object ( the one you just motion pathed)
Connect the uValue of the first motion path the uValue of the second
I'll often stick a add double linear inbetween if I need to do any offsetting.
When this next job ships I've got a behind the scenes that involves lots an lots of paths.
-=s
Unrolling Rig
Slug
We have a fairly complex character rig, kind of a slug like thing that needs to move across a surface and deform to the surface as it goes. The surface it's on is also deforming underneath it.
The solution we have is basically putting it on a wrap deformer "raft", with the wrap deformer itself constrained to the surface underneath by a bunch of geometry constraints.
It works pretty well in some situations, but where there are great differences between adjacent surface normals (the surface its on is poly) we get unwanted popping/jitter in the clusters with geo constraints. This can be alleviated a bit by smoothing the surface, and thus making the faces smaller and therefore the differences between face normal directions smaller with each smooth, but at some point this tops out and we still can't get rid of all the jitter.
One solution is to bake to keys on the clusters and edit the curves, but for a number of reasons that's kind of impractical for us, and even then I'd still like to find a way to get better results from the geo constraints to begin with to minimize the amount of editing required.(Steve Davy)
Vehicle
Auto/Manual Wheels
Wave
use wave deformer. No, just kidding
One way is to loft a nurbs surface and have a lot of curves with wave-shaped inbetween blendshape. Someone has put up a nice demo video, I'll try to find and re-link to it one of these days.