Hi Dr. Sassi,
Thanks for the response.
Before I mislead you, my statement above mentioning Maya was not supposed to make Cinema4D behave like Maya. While it might look that way, my real intention is that a proof that the logic is possible. In this case, the logic that it is possible to eliminate the unnecessary rotation on a Stretchy IK Chain since it is not present in Maya or in Blender.
That is why I’m looking for confirmation if this possible in Cinema4D.
Anyhow, based on your reply above, there is some sort of internal calculation in the IK tag that overrides the constraint. Be it noted that the wrist_joint is already constraint to the rotation of the goal. And it is still rotation independently of the goal. The main reason I flag is as unnecessary.
RE: no pole
This is for illustration. Just had to make it as simple as possible. With regard to pole, it doesn’t matter with or without pole. The behavior is the same.
RE: character rigs.
Yes, it is possible to separate the joints but I’m trying not to and simplify it.
Anyway, with regard to the separated wrist joints, as I checked on the file, it’s either the split joint is for the twist/bendy set-up or as a palm joint (i.e. wrist02_jnt)
Anyhow, the reason it works on the Character Rigs shipped in C4D is that the stretch is set to Position. I set mine to Bone Scale. Position set-up works well if you have split joints to bind, but not as a vanilla set-up.
In conclusion, I guess its not possible to get rid this unnecessary rotation. I must create a separate set-up for stretchy IK or provide additional constraints around the existing set-up
P.S. May suggest to compressed your videos? For instance, 1 min video can be delivered only on 10mb. The size is feasible enough for consumption as an illustration video. If you are looking for one, try Snagit.