Copy Scale Constraint

The Copy Scale constraint forces its owner to have the same scale as its target.

Nota

Here we talk of scale, not of size! Indeed, you can have two objects, one much bigger than the other, and yet both of them have the same scale. This is also true with bones: in Pose Mode, they all have a unitary scale when they are in rest position, represented by their visible length.

Options

Target

Data ID used to select the constraints target, and is not functional (red state) when it has none.

X, Y, Z

These buttons control along which axes the scale is constrained.

Power

Allows raising the copied scale to the specified arbitrary power.

Offset

When enabled, the constraint combines the copied scale with the owner’s scale, instead of overwriting it.

Additive

Uses addition instead of multiplication in the implementation of the Offset option.

Space

Standard conversion between spaces.

Nota

Since scale is a multiplicative quantity, it should be combined using multiplication, and split into fractions or inverted via power. Thus the use of Power is more mathematically correct than Influence, which uses linear interpolation. The use of the Additive option is also not recommended.