public float getGravity() {
        return character.getGravity();
    }
Alter the character's gravitational acceleration without altering its
"up" vector.

@param value the desired downward acceleration (in physics-space units
per second squared, default=29.4)
jme3-jbullet/src/main/java/com/jme3/bullet/objects/PhysicsCharacter.java