#IK advice?
3 messages in this thread
After working with special effects makeup and animatronics for years, I was
delighted to finally get bones and IK for 3DS. My first assignment for myself
was to create a realistic articulated human head. Well, work is under way and
it is looking pretty good, but I am trying to do some tricky things with IK to
get my bones to behave like actuators I would create for a mechanical head.
Maybe someone who has mastered the IK IPAS can help me out.
I have a series of bones running through the upper and lower lips. What I want
to do is set up the IK chain for each lip so I can grab the bone in the center
of each series and move it around and have the bones on either side follow,
with the chain anchored at the corners of the mouth, sort of like a rope tied
at both ends to posts. Is IK capable of this?
Also, I am having problems getting dampening to work right. I need the jaw
bone to rotate without moving the rest of the head until it reaches its limits,
but it affects the head when it is moved at all. I have tried to play with the
dampening setting with no success.
Does anyone have any advice?
Thanks
Mitch
I am not sure equating bones with armatures will work very well. I did make up
and prosthetics (did you ever take Dick Smith's make up course?) and all that
on an amateur (occasional professional) basis for a while before I got my
current job, and I approached bones the same way and found it doesn't quite
work the way you think. The manual says use fewer, larger bones, but I have
found that more and smaller seems to work better, with carefully placed anchor
bones.
I am not an IK expert, but I don't think you can use IK as you desire. It
sounds like you want more of an elastic type of movement, and as far as I know,
IK doesn't have any type of setting to accomdate this type of movement.
You might be better off making many small boxes around the lips, and link them
to a center object behind them in the throat.
I got that idea from Glen Melenhorst and it worked a lot better than the way I
was trying before. You might want to try it.
Hi Mitch,
<< What I want to do is set up the IK chain for each lip so I can grab the
bone in the center of each series and move it around and have the bones on
either side follow, with the chain anchored at the corners of the mouth, sort
of like a rope tied at both ends to posts. Is IK capable of this? >>
This doesn't sound too different from moving a human pelvis and keeping the
feet placed on the ground while using IK. I would have 2 dummy objects placed
at the corners of the mouth. You could use either Interactive or Follow to move
the mouth_center_bone and then use the Follow Object to solve for the end
effectors' placement to the static mouth_corner_dummies.
This is very similar to keeping feet on a moving/flexing diving board while the
body is compressing/elongating.. Please see the following file if you haven't
reviewed it yet..
File Info for FLIP.ZIP
Section: Mesh/Project Files Contributor: 73172,1351 Size: 95951
Submitted: 10/21/94 Type: Binary Accesses: 15
Title: IK Backflip
Keys: IK FLIP R4
This is an example of using IK a number of different ways. A woman doing a 1
1/2
back flip off of a diving board. There was no keyframing of the board or the
woman on my part. All movement solved for by using IK. This zip includes a
solved version and an unsolved version so that the R3 users can compare the
two files. Note also the flip.zip (a flip.fli) in the Animations section of
the lib. IK'd and uploaded by jonas.
[dl time at 2400 baud: 7 min]