/usr/share/java/j3dutils.jar is in libjava3d-java 1.5.2+dfsg-9ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/java/j3dutils-1.5.2+dfsg.jar
/usr/share/java/j3dutils-1.5.2+dfsg.jar