Proceedings, VRML 99, Forth symposium on the virtual reality modeling language, Paderborn, Germany, February 23-26, 1999 - Bauer, C. (Christian); Diehl, Stephan; Balaguer, Jean-Francis; Spencer, Stephen N.; Association for Computing Machinery. Special Interest Committee on Computer Graphics; Association for Computing Machinery. Special Interest Group on Data Communications; VRML Consoritium; Gesellschaft für Informatik (Association for Computing Machinery, 1999)