To convert the movement of a controller bone into a tilt for another bone, you can use a combination of transform constraints and IK constraints in Spine. By setting up a transform constraint, you can link the translation of one bone to the rotation of another. This allows you to achieve the effect where moving a controller bone results in the tilting of another bone. You can adjust the mix settings of the transform constraint to control how much the movement affects the tilt. Additionally, using IK constraints can help in achieving more complex movements if needed.

rmx Spinebot's answer is correct. I just want to add a little more because I think it might be difficult to understand just the words. For example, the following rig is possible:

The controller bone you mentioned is probably supposed to be farther away than the bone you want to move, so I created this example based on that assumption. In this example, the bone you want to move with the controller bone is constrained by an IK constraint, and its IK target bone is set to the Controller bone. This way, the bone you want to move has its own angle of rotation, but changes its angle in response to the movement of the Controller bone.

Here's a more advanced example:

In this example, the IK-target bone is a child of the IK-holder bone, which is rotated 90 degrees. Also in the transform constraint options, the Local option is enabled. This way the local transform of the IK-target bone will be modified by the movement of the Controller bone. This allows the IK-target bone to translate in a 90-degree rotated direction, i.e., upward, when the Controller bone translates to the right.

Here is the Spine project file where you can see this rig:

rmx Oh, I see, so you were referring to shear when you said tilt. Unfortunately, it is not currently possible to convert translate motions to shear. Adding the ability to allow a specific transformation to affect different types of transformations in this way is on our roadmap:
EsotericSoftware/spine-editor121
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