To prevent three dimension applications developed using jMonkey Engine from being pirated, a robust software watermarking algorithm was proposed. A watermark based on an initial sequence of scene-graph-traversal was embedded into the software by a numbering system. Since the initial sequence was a very important clue for extracting the embedded watermark, it should be only known by the owner. Furthermore, the algorithm for embedding and extracting the watermark was discussed. Analysis shows that the new method is more robust. And it enjoys the advantage that the size of scene graph does not be changed.
