3D GUIs (was: metaphors)

[Jecel Assumpcao Jr <jecel@lsi.usp.br>]

Thierry Goubier wrote:
> On Mon, 10 Jun 1996, Jecel Assumpcao Jr wrote:
> > [current prototype is slooooow]
> If it runs only "reasonably well" on a Pentium 166, you'll have a really
> hard time rewritting it.

I am going to simply throw it away and write a very
different one. The current prototype was built just
to see how things would look like.

> The usable on every kind of computer is a very
> hard thing to achieve (using Xwindows on a 386 is far from a pleasant
> experience).

I found Xwindows quite useable on a 386 with Linux, even
when I had only 4MB of RAM! It certainly feels faster on
my machine than on a SparcStation 2.

I think the my design for a 3D engine should work reasonably
well on both slow and fast computers. It works by assuming
that people only see in details when things are not changing,
so I do quick 2D approximations when objects are moving and
then clean things up in the background when they stop. This
is ugly, but responsive on slow machines but becomes
unnoticable on faster machines. This is much like adaptive
compilation. 
 
> The second point is that the response time helps greatly; if any move is
> costly, the user will be afraid of moving.

Exactly, but I think my two step drawing method will solve
this.

> What I believe is that hyperjumps are the crucial feature, susceptible to
> get anyone lost if they jump too much. The problem is the same as with
> hypertexts, and has no easy solution without restricting the freedom of
> organisation.

Jumping from room to room would be roughly equivalent to
changing directories in most systems. Users don't normally
do it very much.

> I prefer the way the 3D file browser is done in a SGI. The best thing
> thoses new metaphors may gave us is an ability to view more things at the
> same time. Freedom of movement is important. I like Pad++ for
> this; there's a great freedom of self-tuning, to view differents aspects.

I like the PAD interface very much, and was tempted to use
it for Merlin. In fact, nothing prevents me from having
some room be PAD styled since each room is really a self
contained universe with its own rules. The problem with
PAD is that while the user can freely move about, the objects
feel as if they were "stuck" on a surface and their
relations are a bit hard to change.

> You have to remind that, when there's hyperjumping and a lack of
> landmarks, to get lost is easier.

Back to my rooms analogy with directories, just because
you have them you don't have to use them. A user can
put all his objects in a single room and never have
to hyperjump at all. And while landmarks are not built-in,
you can drop objects as Hansel and Gretel did and create
your own landmarks (as long as no one comes along and
eats them ;-).

> The second point is that automatic / computer based logical spaces are
> rather bad approximations of the user logical spaces. For example, in
> hypertexts, they're mostly useless.

My ideas is that these rooms will be manually organized.

> For this, I prefer to integrate a support for a user-defined
> categorisation, but without enforcing a strict one, like completely
> separated rooms. The second point is that we have, as human, a good
> ability to look in the large; to extract trends from a mass of data
> correctly presented. To exploit this, you have to allow differents levels
> (from an elementary view to a view-in-the-large) and a representation
> which reacts correctly for each level.

You don't have to have separate rooms if you don't want
to, as I mentioned above. And there should be many levels
of organizing objects inside rooms beyond just spreading
them around. One object might be a catalog with hundreds
of other objects for you to view (a multipage factory
morph, for example).

-- Jecel