Feb 1 & Feb 6
Here is a collection of information provided in the class.
Here is a link that explains gimbal lock: http://www.anticz.com/eularqua.htm
“Every system that uses Eular angles will have this problem. The reason for this is that Eular angles evaluate each axis independently in a set order.”
The solution for this is to use Quaternion.
2. Different Kinds of IK Approaches
Classic Approach ( Linear Approximation): Not efficient
– Jacobian Transpose
– Jacobian Pseudoinverse
– Damped Pseudoinverse
– Use Nullspace to achieve objectives ( can be used to solve singularity problem)
– Priority ( e.g. hands moving but want to keep feet on the ground)
Solve 1st priority with damped, 2nd with nullspace.
Priority Chain: keep projecting into nullspace
– Linear Search
– CCD ( much faster)
– FABRIK (forward and backward reaching IK)
Other Interesting papers can be found here: http://graphics.cs.cmu.edu/nsp/course/15464-s17/lectures/Feb6ReferenceList.pdf
After the class, I find not classic ways easy to implement and also, from what I have seen, have more natural result than classic ones. More research will be put into this and I will keep updating this post.