This is something I’ve done in the past and I’m experiencing amnesia as I can’t recall how I did it.
I select the bone in pose mode.
A Follow Path constraint is added.
In the Target field I enter the name of the curve to follow, then press Enter.
The field remains blank which means Blender does not like something.
I know that I need to Parent the bone to the path, but they are two different objects. When the armature is selected and I shift-click the path then press ctrl-P and choose “Follow Path”. Blender immediately displays a very noticeable bug.
My mesh, which was in front view (numpad “1”), shifts to the top of the window and is in a top-down view (numpad “7”). All the numpad-view keys (1,3, 7) change their viewpoint. Numpad-1 becomes -7. Numpad-3 remains numpad-3 but the viewpoint is rotated 90 degrees, so my character is vertical, head towards the left of my monitor and looking down. Numpad-7 becomes numpad-1 with a 180 degree rotation with my character upside down.
Can someone please comment on my parenting problems and then this Blender bug?
Don’t parent anything to the path curve. The way you explained it is correct: select bone in pose mode and type the name of the curve as target. The only reason for a blank field is incorrect syntax or case. There’s a difference though, in adding a constraint in Pose mode and Edit mode.
When I did this successfully before, I would select the bone in Pose mode. Then add a Follow Path constraint and fill in the fields.
My curve is named “pranayama.L”. But when I enter that name into the Target field of the constraint, it is not accepted. I then switch to object mode, select the path, and verify the name is “pranayama.L”. Why this does not work is beyond me!
Going postal over a simple Blender problem seems a waste of good ammunition. These should be the necessary steps:
** Pose mode
** Select bone
** Add Follow Path constraint
** Enter name of path as Target
If your foundation is not correct, the result cannot be correct.
After a great amount of time just futzing with Blender, I discovered that the name of path was actually different than my belief. Problem solved.
What I learned is more important. When a problem occurs, one must continue analyzing until every aspect of the task is found to be faulty or correct. After gaining enough knowledge, then changes can be made.
Now I need help with constraints. A simple “Follow Path” constraint appears a bad choice because when my arm bone is constrained and the Z (or other) axis points along the path, the arm assumes rather strange positions. I need one joint, the base of the wrist, to follow a path. Depending on the axis selected to remain parallel to the path, the arm assumes different (and all anatomically uncomfortable) positions.
You need to put an IK solver bone in there somewhere (wrist) and constrain it to the path. That way the (unhindered) IK chain does what it’s supposed to do; follow the solver. If you constrain one of the IK bones to the path then the FollowPath constraint fights with the IK constraint.