Feet Twisted in IK mode

[scottfredeman]

Hi Thomas,

I just emailed you a link to download this Blend File.


Thank you,
Scott

[bruno.chansou]

Same problem for me with new character. I run with mac osx 10.6.5
But I try with a more old character create on Feb. 13 (when there's no proxy) and feet don't twist when it goes into IK.

[ThomasL]

The problems seems to depend on the size of the character. When I try with the default character, which I usually do, the twist is noticeable but quite small. A child has big problems, though. I still don't understand what is going on here.

[scottfredeman]

Hi Thomas

Is there any work around in Blender settings to untwist feet after import until you guys find out what's happening? Also did you see my other post about making a script for shape keys to work like your lip sync buttons where we don't have to adjust sliders 3 times with each shape key? I love lip syncing with your one button for each mouth shape. If this can be done with any object in shape keys it would be extremely useful on any model.
Thanks
Scott

[ThomasL]

The problem with twisted toes has been resolved. It seems like roll angles are very delicate creatures for bones that do not line up with the main axes. E.g., the toe for the default character has its X axis pointing right, but for a child it points straight down. The twisting is determined by the difference between the roll and the pole angle of the IK constraint.The pole angle that is good for the adult thus twists the child's feet 90 degrees.

My solution is to recalculate the roll on import, to make sure that the toes and feet have Z up for all characters. This requires a new command in the mhx importer, which thus had to be updated. However, the child now has a new problem with the knee pole targets, which I have not understood yet.

As a workaround you can change pole angles so the knees point forward in the default position. Not sure if this is enough, though.

[scottfredeman]

Hi Thomas, Will that update be in the Mac Version of Makehuman tonight?

Are the knees so bad that it would be better for me to wait until that is Fixed before I get the update?

Thanks
Scott

[ThomasL]

As I wrote in today's blog post, the importer may need to change the rest pose. But this is character dependent, so maybe you will not have this problem.

Blender will try to bend the knee in the direction that its rest location deviates from the line between the hip and the ankle. The problem with MH's rest pose is that the knee is located almost exactly on this line. So even if the distance between the knee and the line is small for all targets, it may point in totally different directions.