Wednesday, June 15, 2011

3 bone leg chain or 2 bone leg chain?

After almost completing my leg rig, Dipti comments!!

Dipti- Your third leg joint is breaking, this is not correct.
Ruha- I saw few tutorials, they follow the same techniques.
Dipti- In prana these kind of characters were famous, so I am quite aware of the joint structure. You will have to create a 3 joint leg chain.
Ruha- Isn't there any other way, the DT tutorial have a horse rig and it works on 2 joint leg chain.
Dipti- That is a horse, your werewolf leg is quite different.
Ruha- @#$^, I am screwed. I have spend 3 days working out the IK FK leg and now I need to create it once again?

I am now tensed, very tensed.

I need to finish this rig soon, I don't have time :(

This is what I am talking about (I have send this question to the CG Coach tutors):

I created a 2 bone leg chain for the digitigrade , and for the third joint I added a separate bone like a human heel joint.



The issue I am having with two bone leg joint for the leg is that on translating the  leg on the right or left side the third joint doesn't maintain the angle, it seems like the leg joints are breaking. I quickly created a 3 joint leg chain to compare and show what I am talking about. What do you suggest in this, what kind of joint setup would be better?


Haven't yet receive any answer from CG coach, its been 6 days.

Why not an inverse foot 2 joint IK?
  -Because you need to manually rotate the last joint every time you translate the leg. Although its easy for me and the animators are acquainted to the inverse foot, I want to go more advanced and discard the need of creating and animating one more control. Knee and ankle are always linked together, so a setup is required to automate their relation.
  -Now if I create a 2 bone IK, it should effect the complete leg, that is the knee as well as the ankle.
  -The leg should remain STRAIGHT when you translate the IK

These are one of the prime reasons why I am researching on digitigrade leg rig which has 2 IK but still works like a 3 bone chain.


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