public void setZoomOutTrigger(Trigger... triggers) {
        zoomOutTrigger = triggers;
        if (inputManager != null) {
            inputManager.deleteMapping(CameraInput.CHASECAM_ZOOMOUT);
            inputManager.addMapping(CameraInput.CHASECAM_ZOOMOUT, zoomOutTrigger);
            inputManager.addListener(this, CameraInput.CHASECAM_ZOOMOUT);
        }
    }
Sets custom triggers for zooming out the cam default is new
MouseAxisTrigger(MouseInput.AXIS_WHEEL, false) mouse wheel down

@param triggers the desired triggers
jme3-core/src/main/java/com/jme3/app/ChaseCameraAppState.java