@Override
            public Void call() throws Exception {
                SnapshotJob job = new SnapshotJob(done, scene);
                jobs.add(job);
                return null;
            }
Takes a snapshot of the surrounding scene.

@param scene the scene to snapshot.
@param done a callback to call when the snapshot is done.
jme3-core/src/main/java/com/jme3/environment/EnvironmentCamera.java