Re: Re[2]: proposed new Media Type application/iges

Ed Levinson (elevinso@Accurate.COM)
Wed, 22 Mar 1995 10:42:09 -0500

Keith Moore and Mitra posit the following reasons for a 3D

One can forward a 2D image to a fax and you can't do that with
a 3D one.

2D viewers exist that handle multiple 2D formats; similarly
for 3D viewers. Hence different default behaviour or separate
mailcap entries for 2D/* and 3D/* make sense.

The problem for me is that these arguements can be made for a
"spreadsheet" type as well. Perhaps this points to a fundamental
problem with the MIME audio and image types, the justification for
them being at the top level is not strong. Finally, I observe that
there is an implicit identity, image == 2D. Does that need to be?

Question. Does it make sense to register IGES as application/iges
while the introduction of a 3D type moves through the IETF? The
practical experience might shed light on these issues.


On Tue, 21 Mar 1995 19:19:07 EST Keith Moore wrote:
> I suspect that 3-D models don't fit well into (2-D) image/*. Can you
> usefully display a 3-D model with a fax machine? Seems like you at
> least need to be able to interact with the model so you can change
> perspective, etc.
> By definition, *any* new type fits into application/* if it doesn't
> fit into some other category. The question is, do these types need
> some special handling beyond application/*?

On Tue, 21 Mar 1995 16:41:15 PST Mitra wrote:
> ...
> I look at this with the question, "What kinds of things can we do to these
> files", for an image the answers are things like display, scale, convert to
> another image etc, in many cases a 2D display may be willing to accept an
> image of any of several sub-types. On receiving an unknown image, launching
> a generic viewer (like xv) may make sense etc.
> The same answers apply to the disjoint set of 3D files, for example DXF,
> RenderWare, VRML, ACE, these describe a 3D object (not neccessarily a
> particular view on it), many tools can read one of the formats and convert
> to the others. Common actions include viewing from different angles,
> rotating, moving through them etc.