John Carmack on id Tech 6, Ray Tracing, Consoles, Physics and more

J

johns

Isn't "ray tracing" an analog approach to graphics?
I remember it was all about "beam steering" on your
crt which gave you smooth lines OK, but they relied
on phosphor latency ????? Holy Cat! Back to the
beginning of time we go. Drag out your 20 msec
LCD monitors just to start.

Frankly, I think they should take a "serious" look
at the new Excel Graphics Engine that is included
in Microsoft Office 2007. An Excel spreadsheet
makes an excellent bit-mapped display, and imagine
a 3D coordinate system of 3 Excel spreadsheet
pairs on each axis. It would be a simple matter to
dither a coordinate pair for line smoothing, and the
data structures needed are already built-in. It would
take very little futher research to complete this
engine and bring it to the Microsoft Gaming market.

johns
 
B

Brian Siano

johns said:
Frankly, I think they should take a "serious" look
at the new Excel Graphics Engine that is included
in Microsoft Office 2007. An Excel spreadsheet
makes an excellent bit-mapped display, and imagine
a 3D coordinate system of 3 Excel spreadsheet
pairs on each axis. It would be a simple matter to
dither a coordinate pair for line smoothing, and the
data structures needed are already built-in. It would
take very little futher research to complete this
engine and bring it to the Microsoft Gaming market.

Someone's been reading Gamasutra; a lengthy article on this precise
subject appeared there this past month.
http://www.gamasutra.com/php-bin/news_index.php?story=17749
 
B

Bob Myers

johns said:
Isn't "ray tracing" an analog approach to graphics?

In short, no.

I think you have the term "ray tracing" confused with
the concept opf a "vector-scan display."

Bob M.
 
B

Bob Myers

johns said:
Yes. What is the difference?

Two completely different things.

"Ray-tracing" is a technique used in computer graphics in
which light is modeled as individual "rays," which are mathematically
"traced" from their source, as they reflect off various objects in the
scene, and then to the viewpoint of the hypothetical viewer
or camera (or the other way around). Imagine starting with a particular
spectrum and intensity of light, and both are modified as the rays
are reflected by the objects in their path. Do this with a very large
number of rays, and you can get a very good-looking image including
natural-appearing reflections, shadows, and so forth. It can also produce
accurate modeling of refractive effects - e.g., the appearance of objects
as seen through a lens, or water. (It turns out that the "rays" are most
commonly traced from the supposed viewer or camera point back to the
source, rather than vice-versa, for reasons of computational efficiency.)

A "vector-scan display" is a type of display device (now
for the most part obsolete, at least in its CRT-based form,
although there have been some laser-based displays which
are basically "vector-scan" devices). Instead of building
up an image as a regular pattern of lines, and varying the
intensity of the light as that pattern is scanned (as in a
raster-scan CRT), a vector-scan display works by essentially
"painting" the outlines of objects to be displayed on the screen,
typically (as noted) a fairly long-persistence CRT. This method
works very well for making clear, sharp images of a simple
"line drawing" sort, but producing images of "solid" objects
and doing full color are both virtually impossible.

Bob M.
 
J

johns

I believe we touched on ray tracing in one AutoCAD
class I took ( AutoCAD 11 ). My vector days were
with an Apple II .. or a ZX80 .. I forget. Starting to
sound like JC wants us all running Quadro 5600s
on quad cores ... and crappy games. One 5600
costs more than my entire game box, and my
game box is an 8800 in a Duo 6750. Lord !

They need to get busy at Intel, and put all of this
on one chip.

johns
 
B

Bob Myers

johns said:
I believe we touched on ray tracing in one AutoCAD
class I took ( AutoCAD 11 ). My vector days were
with an Apple II .. or a ZX80 .. I forget.

I seriously doubt that you had a vector-scan display
on either of those, actually.

Vector-scan != line-drawing in general.

If you want to see what a real vector-scan display
looks - or at least LOOKED - like, take a look at
this:


Bob M.
 
J

johns

I had an Analog Devices chip that would do
beam steering on an old scope. That is all
I remember that looks like the YouTube demo.
I think I remember a book on graphics on
an Apple II, and one of the chapters was
"vector graphics", and I went through the
excercises, and actually drew one line
across the TV screen. My biggest, world
class, achievement at the time was getting
the letter "A" programmed right in the middle
of the screen. Those were the days. JC was
probably in diapers.

johns
 
B

Bob Loblaw

johns said:
I had an Analog Devices chip that would do
beam steering on an old scope. That is all
I remember that looks like the YouTube demo.
I think I remember a book on graphics on
an Apple II, and one of the chapters was
"vector graphics", and I went through the
excercises, and actually drew one line
across the TV screen. My biggest, world
class, achievement at the time was getting
the letter "A" programmed right in the middle
of the screen. Those were the days. JC was
probably in diapers.

johns

It's pretty ironic since at your age you're the one wearing the diapers now.
 

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