SplineSoup Posted July 21, 2016 Share Posted July 21, 2016 Hey everyone! I'm working on rigging a character for an upcoming short film and have a puzzle to bring to the table regarding hip/thigh rigging. While rolling the thigh bone on my character (and pretty much every library character), I observe a disconcerting tendency of the pelvis to simply collapse. To remedy this, I'm exploring the use of a chain of "fan" bones to distribute the roll of the thigh along a series of thigh cross-sections, giving the hips a much-needed break. I've currently tested my design with a simple tube model and the results look promising. It basically works like this: A chain of roller bones is constrained to the thigh and the thigh geometry is assigned to them. The rollers are constrained to Orient Like the thigh, but the roll is achieved by separate Roll Like constraints which gradually add up to the full roll of the thigh by the time they reach the knee. Spiffy! I was pretty proud of myself...until I brought this back to my actual character model and realized that legs are not perfect tubes! The conundrum I'm facing now is that I want to apply this principle to a thigh bone that is not straight up and down and to leg cross sections that don't perfectly line up, vertically. Between proper bone hierarchies and constraint options, I'm currently stuck. I've attached the project file with my two concept tests. Any pointers on how to create a chain of roller bones that move with a thigh but maintain their own unique pivot points along the leg so that each leg cross-section rotates, more or less, around its center? Thanks! Thigh Roll Test.prj.zip Quote Link to comment Share on other sites More sharing options...
zandoriastudios Posted July 21, 2016 Share Posted July 21, 2016 I did a Siggraph video covering this issue. I cover the fan bones for shoulder and thigh, and also smartskin: https://youtu.be/gkBmYlRwP_8 Quote Link to comment Share on other sites More sharing options...
Hash Fellow robcat2075 Posted July 22, 2016 Hash Fellow Share Posted July 22, 2016 ...The conundrum I'm facing now is that I want to apply this principle to a thigh bone that is not straight up and down and to leg cross sections that don't perfectly line up, vertically... I'll note that even though a real thigh is not a perfect cylinder, it does have a single axis that it turns around because the thigh bone is attached at a socket that it can not depart from (we hope). Quote Link to comment Share on other sites More sharing options...
SplineSoup Posted July 23, 2016 Author Share Posted July 23, 2016 I did a Siggraph video covering this issue. I cover the fan bones for shoulder and thigh, and also smartskin: https://youtu.be/gkBmYlRwP_8 Thanks for the tip. This is a fantastic overview of the rigging process and has so far shown me that I've been doing CP weighting in a pretty Jurassic way. I'm about 1/3 of the way through and ended up weighting the character's torso while I watched. Looking forward to the section on shoulders and hips! Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You are posting as a guest. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.