Influence

The influence slider next to each constraint is used to determine how much effect the constraint has on the transformation of the object.

If there is only a single constraint in a block (a block is a series of constraints of the same type which directly follow one another), an influence value of 0.0 means the constraint has no effect on the object. An influence of 1.0 means the constraint has full effect.

If there are several constraints in a block, the influence values are used as ratios. So in this case if there are two constraints, A and B, each with an influence of 0.1, the resulting target will be in the center of the two target objects (a ratio of 0.1:0.1 or 1:1 or 50% for each target).

Influence can be controlled with an ipo. To add a constraint ipo for a constraint, open an ipo window and change its type to constraint by clicking on the appropriate icon.

Next click on the Edit Ipo button next to the constraint you wish to work with. If there is no constraint ipo associated with the constraint yet, one will be created. Otherwise the previously assigned ipo will be displayed. At the moment, keyframes for constraint ipos can only be created and edited in the ipo window, by selecting the INF channel and CTRL+LEFTMOUSE in the ipo space.

When blending actions with constraint ipos, note that only the ipos on the armature's local action ipos are considered. Constraint ipos on the actions in the motion strips are ignored.