Having some trouble understanding IK

[Keith_Scholes]

I must confess I am struggling a bit with understanding how IK works and I am beginning to wonder if there are some problems with it, although that might just be my lack of understanding. In particular when setting the constraint limits for the y axis no coloured circle appears to show the limits visually unlike the x (red) and z(blue) axes , this also seems to be case in the video. I have tried looking from various viewpoints such as top down but nothing is visible. Consequently, I am wondering if Blender is setting limits on the y axis at all.

Additionally at about 6:22 in the video Mike appears to move the the bone in the x axis and this movement appears to change the minimum limit for the x constraints. How does he achieve this? I have tried for some time to repeat this in my own model, but without success.

[Jaco_Pretorius]

Hi Keith

The IK section threw me off a bit also but I got there eventually… here are some things to keep in mind:

• You need to be in Pose-Mode to see the bone constraint arcs. (Shift-Tab from Object-Mode)
  
• You need to first remember to remove all of the bone-constraint-modifiers from the previous lectures… they can mess with your results quite a lot. (You can only access bone-modifiers in Pose-Mode)
• Remember that the bone-constraints apply to the actively selected bone in the view-port.
• On my system, if you are using auto-IK, then the view-port won’t update like at 6:22 in the lecture - you need the IK modifier applied to see real-time effects.
• The armature will only move like it did at 6:22 if you’re in Pose-mode, and the armature is at an angle which is less (or greater) than the one you’re limiting. If you set the value while the armature angle is in range you won’t see effects.

I hope something in there helps with your current predicament.