Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!uunet!husc6!uwvax!uwmacc!uwmcsd1!marque!gryphon!crash!pnet01!haitex
From: haitex@pnet01.cts.com (Wade Bickel)
Newsgroups: comp.sys.amiga
Subject: Re: IFF for 3D packages?
Message-ID: <2070@crash.cts.com>
Date: Wed, 2-Dec-87 14:36:28 EST
Article-I.D.: crash.2070
Posted: Wed Dec  2 14:36:28 1987
Date-Received: Sun, 6-Dec-87 08:47:51 EST
Sender: news@crash.cts.com
Organization: People-Net [pnet01], El Cajon, CA
Lines: 52

mp1u+@andrew.cmu.edu (Michael Portuesi) writes:
>With all the talk about interchange programs between Videoscape 3D,
>Sculpt 3D, Forms in Flight, etc etc. I begin to wonder why an IFF
>format for describing three-dimensional objects has not surfaced.
>After all, isn't the whole intention of IFF to avoid kldugy
>conversion programs and allow various packages to work in tandem?
>
>It wouldn't be hard at all to adopt such a standard.  Everybody need
>only offer IFF capability with the next release of their package,
>with backwards compatability for the old format.
>
>
>Michael Portuesi / Carnegie Mellon University
>ARPA/UUCP: mp1u+@andrew.cmu.edu		BITNET: rainwalker@drycas
>
>"little things remind me of you...cheap cologne and that damn song too!"
>		--The Flirts, "Jukebox"


        I've been working with 3-D images and image formats.  I think
      you underestimate the difficulties in creating such a format,
      but since so many others have responded to this posting and pointed
      some of these difficulties, I will not do so.  Instead, here is my
      format:

                OBJECT  =  RECORD
                             type : CARDINAL; (* EASIER THAN USING SETS *)
                             DATA : POINTER TO LIST OF DATA;
                             CODE : POINTER TO RENDERING ALGORITHM;
                             ORIENTATION_DATA : DESCRIBES OBJECT'S POSITION
                                                  AND ORIENTATION;
                             LINK : USED TO "CONNECT" OBJECTS;
                           END;

        In this way, each object can utilize a custom rendering algorithm.
      This is very important, as the nature of the image often allows 
      significant shortcuts to be taken.  I am not in favor of any format
      for the point/triangle/polygon data, or for there to be multiple 
      formats.  I would not want to be contrained to using floating point
      data, so the format must recognize a variety of data types.

        This format works well for me. Obviously its fairly un-developed.
      Any comments/suggestions will be greatly appreciated.


                                                Thanks,

                                                        Wade.

UUCP: {cbosgd, hplabs!hp-sdd, sdcsvax, nosc}!crash!pnet01!haitex
ARPA: crash!pnet01!haitex@nosc.mil
INET: haitex@pnet01.CTS.COM