Hello. I was playing with bendy bones and decide to build spine rig flexible as rigify but simplier and easy to animate. Instead of using bone chain for spine (like in most rigs) I used only one segmented bendy bone with standart head\tail setup with "stretch to’ constraint. I added some additional bones - pelvis, hips, legs arms and evertything works.
Spine bone is curving nice, so I almost satisfied with such rig but I have problem. If i add some bones in the miidle of this spine bone (breast bones) and parent them to spine they don’t follow spine curve when i rotating upper bone (tail bone):
AFAIK there currently is no way to easily access the Bendy Curve in order to use it as influence on rotation angels on other bones…
that’s why most spine Riggs have about on average 3 bones to simulate the spine bends…
this may not always be the case however as perhaps one could use the rotation angels of the bendy bone handles or stretch too targets…
via copy rotation constraints…
but AFAIK there currently is no way to access the curve data out of a bendy bone…
(this may change in the near future with Blender 2.8-2.9-or3.0)
Thank you for reply. So if there is no access to bendy curve that’s mean no breast bones. Anyway for cartoony characters such flexible spine rig is good for me. Hope someday they will improve bendy bones functionality.
imo using single bendy-bone for whole the body is a bit wierd. there are ribs and pelvis which are not expected to be stretched. but these bones can be used as reliable base (parent) for legs and arms (breast)). I’d recommend the following video (timestamp is pointed to spine bendy-boning)
just modify the ribs/ pelvis bone sizes to better fit the expected behavior
Anyway for cartoony characters such flexible spine rig is good for me. Hope someday they will improve bendy bones functionality.