[comp.graphics] 3D for cheap!

chas@ssc-vax.UUCP (Chas Boyd) (03/31/88)

	Why aren't there cheap dedicated 3D machines out there?  There are
   lots of applications for 3D graphics (like entertainment) that could
   be opened  up if 3D capabilities were cheaper.  Most of the systems 
   currently available seem to use custom blitters to improve two-D 
   performance.  If similar custom processors were made to run 3D pipelines
   in integer math, 3D (i.e. real time) graphics machines might result.
	Many studies have shown that maximum comprehension of 3D data is
   achieved with flat shaded polygons.  The current emphasis on colors and
   bitplanes seems only justified for art departments and IMPRESSING MANAGEMENT.
   (Managers seem to go for pretty pictures, especially when they don't
   understand the content.)
	Can any one help me with the cost estimates and benchmarks that follow?

	20Mhz 68020	using 32bit integer math for 3d transformations
	Scan line access video ram (SLAM) whatever happened to that?
	NTSC compatible display, with 8bits depth
	Under $1000 "home market" price-tag  using TV as monitor

	Wasn't integer math used on the old vector Megateks?  Do you need
   a lot of significant digits if you are only displaying 600x400pixel screens?
   Could the 68020 do 1000 3D pts per second?  What about 16 bit math?
	On most current machines, filling in the polygons is the bottleneck.
   SLAM chips would help here, and you could even use a few Z80s or 6502s as
   blitters if you had 8-bit pixels??  If you use a 68030 do you still need
   a blitter at all?
	The old Apple II had really crummy 2D graphics compared to today's
   Amiga, but now people expect pretty colors and smooth animation at the
   expense of 3D.  If we could get them unspoiled enough they might give
   up a little color to get perspective or 3D rotations.  Surely this would
   blow away the Nintendos and Segas.
	Are there any 3D transformation pipeline boards available for PCs?
	Among workstation vendors only the Iris folks seem to be targeting
   directly for 3D, the others are all still hyped on blitters and various
   shades of mauve and chartreuse for their windows.

	There was an arcade machine called "I Robot" Copyright Atari 1984
   (4 YEARS ago) that had full 3D graphics:  perspective, hidden line
   shaded polygon fill, 3D rotations and real-time animation of data bases
   involving well over two hundred polygons or 500 vertices.  It was the last
   game they got out the door before the big crunch.  Technically it has
   yet to be surpassed in the arcade market. (Current machines like Outrun,
   Space Harrier, or Top Gun are just 2D cut and paste jobs with blitters.)
   It could not have cost much over $3000 to produce, so WHY isn't this 
   technology available now?  Was it all custom bit slice?  Is it a lost art?
   Would you HAVE to use risc/transputers nowdays?
	<end rant>
						Chas.
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ksbooth@watcgl.waterloo.edu (Kelly Booth) (04/02/88)

In article <1038@ssc-bee.ssc-vax.UUCP> chas@ssc-vax.UUCP (Chas Boyd) writes:
>
>	Many studies have shown that maximum comprehension of 3D data is
>   achieved with flat shaded polygons.

I would be interested in references to the literature from the original
poster or from anyone else to such studies.

ewhac@well.UUCP (Leo 'Bols Ewhac' Schwab) (04/13/88)

In article <1038@ssc-bee.ssc-vax.UUCP> chas@ssc-vax.UUCP (Chas Boyd) writes:
>	There was an arcade machine called "I Robot" Copyright Atari 1984
>   (4 YEARS ago) that had full 3D graphics:  perspective, hidden line
>   shaded polygon fill, 3D rotations and real-time animation of data bases
>   involving well over two hundred polygons or 500 vertices.  [ ... ]
>   It could not have cost much over $3000 to produce, so WHY isn't this 
>   technology available now?  Was it all custom bit slice?  Is it a lost art?

	I own one of those monsters.  I bought on the premise that I would
dive inside and re-program the sucker to play _Starfighter_.  To this end, I
managed to get in contact with the game's designer at Atari Coin-Op.

	It turns out the 3D system is based on an AMD bit-slice setup, with
nine bits of resolution (just enough for 512 pixels across).  He pulled
every trick known to man, and a few more besides, to get that thing to
perform the way it did.  It is nowhere near to being a general 3D polygon
manipulator.  The controlling CPU is a 6809 running at 1.5 MHz.

	My conversation with the designer went something like this:

Me:	"Hi.  I'd like to get some programming information on _I, Robot_."
Him:	"You're kidding, right?"
	"No.  I wanna re-program it."
	"No, you don't."
	"....Yes I do."
	"No, you don't.  I designed that thing; I *know* what's in there.
You don't want to mess with it.  It's just too ugly."

	I'd still like to get in there and muck around with it.  I have a
6809 assembler rarin' to go......

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