I have downloaded the 3 packages (j3d-core, j3d-core-utils,vecmath) in netbeans 8.0.1/Windows-Vista/JDK8.
I try now to re-build java3D project like explained in the file j3d-core/README-build.html.
So, I have started ton compile vecmath and it's OK (I got vecmath.jar).
Next I try to compile j3d-core (including the vecmath.jar I have just built) and it fails in Font3D.java at these two lines of import (Netbeans complains that the package com.sun.j3d.utils.geometry does not exist) :
j3d-core and j3d-utils can only be built as a single unit that produces the two jars as they mutually require classes found in the other package. Please use the ant script found in the j3d-core repo as a guide.
It's inconvenient, but that's just the way it is unfortunately.