a graphics library (3D) for Ultrix with DecWindows?

[mlevin at jade.tufts.edu]

    I have Ultrix 4.2 running on a VaxStation II, with the normal
workstation DecWindows stuff (no MIT X stuff, etc.). Are there any
(preferably public-domain) graphics libraries available that can work
with DecWindows and do 3D graphics?  I need it to be callable from
Ultrix C, and seen in real-time (not like saving PostScript commands to a
file, for later print-out, for example). If anyone has a suggestion,
please let me know.

Mike Levin