constraints or expressions for size a bone

[Malo]

Good evening everyone,
I am looking for a way to give the same size of a bone to another bone by the constraints or expressions. Anyone know how we do it?

[Rodney]

I know you can have a bone revert to the size of another via the 'Scale Like' constraint.

One way to do that would be to set that up as a 'On/Off' Pose and then you could toggle between any size set and the original/source bone it is constrained to.

In this same way you can set one bone to be a percentage of the length of another as well.

 

Added: An interesting aspect of creating the constraint within a pose is that it give us a method to tell A:M to ignore the command (in this case of copying the length/scale) when the pose is turned off. If the length/scale of the bone should always be the same length then no pose control is necessary. Of course even then there are alternative ways to interact with the scale... for instance, by using/animating the constraint settings themselves.

[itsjustme]

If the bones are the same size to start out, you can use a "Scale like" constraint. If the bones are different lengths to start out, you can use an Expression similar to the one in this Project. If you have a more specific description, there might be several other methods that could be used...like a simple percentage Pose or Smartskin.

 

Hope that helps, Malo.

bone_sizing.prj

[robcat2075]

I'll add that the "scale like" constraint has a "scale scale" parameter so if the two bones are not the same size before the constraint is applied the "scale like' constraint could still make them so when it is turned on.

[Malo]

Thank you all for your answers !
I'll study it all tonight.

[Malo]

That helps, David! Thank again!