So I’ve been trying to use Spline Ik to animate this scarf, and I keep running into a big problem. For some reason the spline updates one frame late compared to my controllers. I have no idea what is causing it and I’m thinking it’s probably a bug. Does any work-around exist for this problem, or do I have to resort to FK animation to do this?
Hmmm… That’s a somewhat complex thing, even though it looks simple on the surface. (A bit of a head scratcher.) Might be a cyclic dependency in there, given extra bones controlling the bones that hook the spline.
Looks like you’re trying follow the general shape of one curve while manually animating in a sinusoidal wave on another curve. Is that what’s going on in there? (Not obvious at first until bone layers are messed with a bit.)
It’s hard to tell, but the type of animation you’re looking for might be easier with a soft body on just the spline controlling the object rig. Then control IK/FK with influence slider. If you don’t like softbody, there’s one more way similar to what you’re doing, but using a mesh object “string” (maybe there’s a better term, it’s a linear chain of edges) with a cloth modifier.
I had a similar issue with my spline tongue rig (in my wip) where it would lag in the ui but then it would render out correctly , I never found out what caused the lag it will be interesting to see what the possible solutions are if any.
This is for a game rig. It needs very precise control and the animation must loop.
it must also be exported to fbx, So I can’t use simulations like softbody and cloth and such.
FBX export does not remove the lag either unfortunately.
I’m thinking that I might be able to export this piece separately and move the in/out points of the animation. But it’s such a tedious workaround.
@Pauljs75_: You are right that there are two layers of bones controlled by two different splines. the first chain makes it easy to place the end points and the second one follows the controllers parented to the first one. There are no cyclic dependencies. I’ve used this trick in Cinema4D and there it works fine. The delay is there even if you just use a single spline. It just seems to be doubled if I have one Spline IK dependent on another (two frames delay instead of one). This leads me to belive that it is a bug in how the Spline IK is updating.
