@Override
    protected GeometryList getOccludersToRender(int shadowMapIndex, GeometryList shadowMapOccluders) {

        // update frustum points based on current camera and split
        ShadowUtil.updateFrustumPoints(viewPort.getCamera(), splitsArray[shadowMapIndex], splitsArray[shadowMapIndex + 1], 1.0f, points);

        //Updating shadow cam with current split frusta
        if (lightReceivers.size()==0) {
            for (Spatial scene : viewPort.getScenes()) {
              ShadowUtil.getGeometriesInCamFrustum(scene, viewPort.getCamera(), RenderQueue.ShadowMode.Receive, lightReceivers);
            }
        }
        ShadowUtil.updateShadowCamera(viewPort, lightReceivers, shadowCam, points, shadowMapOccluders, stabilize?shadowMapSize:0);

        return shadowMapOccluders;
    }
Sets the light to use to cast shadows

@param light a DirectionalLight
jme3-core/src/main/java/com/jme3/shadow/DirectionalLightShadowRenderer.java