- Editado
making eyes look at a direction within a distance limit?
I think this is probably a feature quest as I can't think of a good way to implement this with existing tools.
I want to make eyes (or something else in other scenario) to move toward a bone target but have the distance not going outside of the eye holes to make things looks right. I can only think of a "distance constraint" that cap the distance from the eye center (of course with scaling support to match the oval shape). Any suggestion with creative way to make it work with current tools are welcome 8)
P.S.the things that my character will look at is moving dynamically on the screen that's why I want to have a moving bone to determine where the eyes should look at instead of hard coding how the eyes moves.
I just made a little project that does something similar for you 
Basically, the project takes advantage of the IK compress property that one bone IKs can activate, which makes a bone become smaller to reach a target, but not bigger if the target is far away. Inverse Kinematics - Spine User Guide: Options
If another bone is parented to the constrained bone, deactivating the inheritance of rotation and scale in the bone properties will make sure it doesn't get compressed with the IK. Tree - Spine User Guide: Properties
cool
I think this could solve my problems.
Thanks