Spline IK handle slides on curve

[Anonymous]

I've been frustrated with the ik spline solver. When the control points of the curve are translated, the ik handle slides along the curve giving undesirable deformations. Someone please help...

[gautham.chandran47]

can you create a video how the deformaton working now ?

[Anonymous]

Video has been attached. The setup is IK Splined joints and 3 driving joints skin bound to the IK Spline curve to control it just like an IK Spine setup. When the driving joints are translated or rotated, it slides the IK handle along the curve. I want it to anchor at the ends of the IK joints. IK Spline settings is at the default.

[gautham.chandran47]

I don't see anything weird with that deformation. That's how it works as default. To be clear, you want the deformation at the middle to stay where it is when you translate or rotate the end?

[Anonymous]

hi I am having the same issue actually. I would like the clusters and controls to move along with the joints. Would appreciate your help

[ridvancakr]

I am having the same problem. Is there a solution? What we want is for the middle joints to move logically while the end joint remains fixed in place. I usually want this to happen in jointers that I give the stretch property to.

[stephenkmann]

by default, the joints do not lengthen and shorten along a curve using splineIK. 

 You need to add connections from the curve length, to drive the length of the joints

this might help

https://youtu.be/KmnynMhcrIA

hth

-=s

[ridvancakr]

Thank you very much, I watched the video until the end but I haven't applied it yet. This seems like a solution for me. I have a small question. Is it possible to keep the "ik spline handle" end point fixed like starting point? Beacue no matter what the starting point is, it doesn't move. I have a cord set for the bag I'm preparing. I need to keep the starting and ending points fixed at all times.

[stephenkmann]

There are several ways that come to mind .. 

1) Is to create a "stretch" setup like the one in my video.. and NOT bind to the last joint in the splineIK.    Then, Bind the curve to several joints.. ( the last joint at the end. also bind the geometry to.. This is because the curve can bend more than the joints in the splineIK..    but it can get very close.

1a) if you need the joint chain to be a single hierarchy, (ex: for game export) .  You could parent Constain the last joint to the "control" joint that the curve is bound to.

2)  use PointOnCurve constraints to place the joints along the curve. but need way to control the up vectors. (like a second curve)

3)  use "motionPath" constraint to place the joints along the curve. but need way to control the up vectors. (like a second curve)

hth

-=s

[ridvancakr]

Thank you very much, I will apply it and share the most effective result.

[stephenkmann]

you can also make a ribbon rig. 

 there are many ways to accomplish what you are trying to do

--=s

[ridvancakr]

I tried all the methods but I couldn't get the result I wanted, so the best method was to create a ribbon, thank you very much for your advice.

[stephenkmann]

with point on curve , or motionpath, you can get the exact same result as a ribbon rig using follicles or uv constraints

good luck

-=s

[ridvancakr]

Thank you, I solved the problem, I took a simpler approach, I installed a ribbon system for the cord part of the bag, and a ik-handle system with a stretch feature for the body part of the bag, then I created hierarchy controller groups, for now everything works as I want.