I am trying to render citygml files. I am using NWW for rendering purpose. I have used citygml4j library to extract the GroundSurface, roof, and walls geometry, and was able to render them. But due to the huge data specification of citygml, I am having troubles with more complex files. So I am looking for some java library that can convert citygml file to kml data format, which can be easy visualized in World wind. I have seen the 3dcitydb and found that pretty cool, but couldn't find any set of apis that can be used for my purpose.(haven't completely explored that).
Does there exist some java library that can fulfill my purpose?