public void setMaxDistance(float maxDistance) {
        this.maxDistance = maxDistance;
        if (maxDistance < distance) {
            zoomCamera(maxDistance - distance);
        }
    }
Sets the max zoom distance of the camera (default is 40)

@param maxDistance the desired distance (in world units, default=40)
jme3-core/src/main/java/com/jme3/input/ChaseCamera.java