That was the bad news, now some good news.

I saw this post only because I have a Google alert
for /applet/ (I consider it my 'duty' to let people
know the far better alternative).

Although I've had no direct experience with J3D, I
have successfully deployed projects based on JOGL
(another 'extra' API) using *webstart*.  It was
almost impossible to deploy JOGL applets *in a
web page*.

It seems some folks are already deploying Java3D
using webstart.
<http://www.google.com/search?
as_q=java3d&as_sitesearch=&as_filetype=jnlp>

In fact, it appears to be quite *easy* to deploy using
webstart, since the Java3D folks provide the API as a
JNLP extension that can be referenced from your own
(JNLP) launch file.
<http://download.java.net/media/java3d/webstart/release/java3d-1.5-
latest.jnlp>

Link to that from within your launch file, and all the
set-up and caching of Java3D should happen automatically
for the end-user.  Better still, if the J3D folks update
the API, the client gets the update automatically - at no
'expense' to your server.

On related subjects, and coming back to 'I only saw
this because..'.

The J3D group on usenet seems rather quiet, but the
Java3D forum..
<http://forums.java.net/jive/forum.jspa?forumID=70>
..at the Java3D site..
<https://java3d.dev.java.net/>
..shows more activity.

Perhaps I should also point out that many of the
comp.lang.java.programmers (I often post there, it
is a very active group) could have figured out
what I told you above.

HTH