public DirtyRegionsIterator getDirtyRegions() {
        if (dirtyRegionsIterator == null) dirtyRegionsIterator = new DirtyRegionsIterator(this);
        dirtyRegionsIterator.rewind();
        return dirtyRegionsIterator;
    }
Get dirty regions

@return Helper object to iterate through dirty regions
jme3-core/src/main/java/com/jme3/shader/bufferobject/BufferObject.java