Amiga Boing Demo - Colorcycling?

NoX1911 · 07 January 2008, 23:13

Hi,
some guy told me the amiga boing demo is just color cycling. I don't think so and believe its real vectorgfx.
There seems to be more than one version since the original was kinda buggy. I took the version tagged as 'old' at pouet.net (26.340 Bytes) and recorded it for review.

This version shows a "ghosting" effect after the red squares with brighter red pixels. These are not video compression artefacts. The pixels are genuine.

What do you think?

Amiga Boing Demo Video:
http://sharebase.de/files/hmqjBCtAUZ.html

Mirror:
http://www.egoshare.com/82a4e79af6b4...ngdemomp4.html

5MB - 1min - 50fps
MP4/h264/AAC

ohforf · 07 January 2008, 23:30

LOL... color cycling

The Answer is... guess where ?
http://piru.dyndns.org/~p/temp/boing.asm

NoX1911 · 08 January 2008, 00:37

Someone captured a pic to check the palette. There are slight color variations because of OS3.1 but color positions seem to be intact.

Hmm, this really looks like color rotation.

Edit: I'll try to recapture the picture with genuine conditions (Kick13) if someone can tell me how to do so?

NoX1911 · 08 January 2008, 01:54

It's definitely color rotation.

Here are both the original captured iff file and MP4 video of the animation:

ohforf · 08 January 2008, 03:49

Hmm... using color cycling to fake the Ball rotation would be smart.
Moving the Ball by color cycling seems impossible. Must be a BOB.
So a legendary Demo that helped selling the first Amigas is in fact
a totally fake 3D Engine ? Funny Stuff.

I will try to find that in the disassembly... later.

NLS · 08 January 2008, 09:46

oh come on people...

heavy · 08 January 2008, 13:32

take a look at the code
hmm...the init and draw globe are called at the start, but not during the mainloop. (real vectors calculated and drawn with mathlib and gfxlib)
seems to only move bitmap, poke colors into the copperlist (7 or 8 colors swapping) and play sound

too bad

Shoonay · 08 January 2008, 13:42

Quote:

Originally Posted by ohforf

So a legendary Demo that helped selling the first Amigas is in fact a totally fake 3D Engine ?

Ouch.

A psychiatrist is needed. Fast.

viddi · 08 January 2008, 14:43

Well, color cycling IS a cool effect, isn´t it?!
And it was something new and special in 1985.

The A1000 could do it in realtime though.

pmc · 08 January 2008, 16:04

I agree and, let's face it, I'm not sure the overall effect would have looked any better if it were coded in a more machine resource intensive way. Why make things more complicated than they need to be? - it still looks cool as it is now and especially in '85!

Photon · 08 January 2008, 17:17

Of course it's color cycling. What's mystifying is how they failed to run it full framerate... I guess they used libraries. If I'd do it, the frame loop would take less than one scanline. (< 0.3 % cpu time.)

NoX1911 · 08 January 2008, 17:33

What do you mean by 'full framerate'? It runs at 50fps. That is pal full framerate.

heavy · 08 January 2008, 17:50

Quote:

Originally Posted by Photon

I guess they used libraries.

all the demo was made with libraries : graphics, intuition, maths...
the vbl sync used 1 WaitTOF.
the good idea is how the globe was drawn for the color cycling

NLS · 08 January 2008, 19:49

Quote:

Originally Posted by heavy

too bad

why?

not really - still Amiga rulez in my book
(and this comes from a guy with three PC at home - one of which an 8800GTX game-power-plant)

Jope · 09 January 2008, 20:36

Heh, if you load it from floppy on a 68000 Amiga and immediately flip WB to back, you can even see it building the bitmap with the wrong palette, it's immediately obvious then that it's color cycling. :-)

Color cycle was a really common Amiga trick back in those days. Waves in the sea (Ports of Call), golden shiny logo (Defender of the Crown), heck even the Xmas scene tutorial in DP1 made heavy use of color cycle. :-)

Christian · 01 February 2008, 12:33

I remember that the boing demo was re-created on the Amstrad CPC back then lol.

I think it was a type-in in Amstrad Action or something (or maybe on a cover tape?) and that it used colour-cycling. As the Amstrad couldn't move a big object around like that I think they used a trick.

From what I remember, the CPC could hardware scroll the screen (really fast) like 8 pixels at a time, and the grid gaps were 8 pixels too. So the whole screen (grid and all) was bouncing around, but the grid looked like it was not moving. The same colour-cycling trick was used for the ball rotation.

Pretty clever really.

Haven't seen it for about 20 years though so my memory is a bit sketchy

(goes off to look for it)

Edit: I think it was called "Blitter"

Sune Salminen · 01 February 2008, 13:32

I remember seeing the boing demo on the 9" screen of a 68k Mac - In black and white.

I'm sure it's out there somewhere.

NLS · 01 February 2008, 14:52

The same demo is also available for C64.

DDNI · 01 February 2008, 17:02

Quote:

Originally Posted by Christian

I remember that the boing demo was re-created on the Amstrad CPC back then lol.

I think it was a type-in in Amstrad Action or something (or maybe on a cover tape?) and that it used colour-cycling. As the Amstrad couldn't move a big object around like that I think they used a trick.

From what I remember, the CPC could hardware scroll the screen (really fast) like 8 pixels at a time, and the grid gaps were 8 pixels too. So the whole screen (grid and all) was bouncing around, but the grid looked like it was not moving. The same colour-cycling trick was used for the ball rotation.

Pretty clever really.

Haven't seen it for about 20 years though so my memory is a bit sketchy

(goes off to look for it)

Girv was heavy into Amstrad back then..... Maybe he has it?

21 January 2013, 04:20

Quote:

Originally Posted by Sune Salminen

I remember seeing the boing demo on the 9" screen of a 68k Mac - In black and white.

I'm sure it's out there somewhere.

It's called Vanlandingham.

07 January 2008, 23:13	#1
NoX1911 2064 Join Date: Jul 2005 Location: de Posts: 231	Amiga Boing Demo - Colorcycling? Hi, some guy told me the amiga boing demo is just color cycling. I don't think so and believe its real vectorgfx. There seems to be more than one version since the original was kinda buggy. I took the version tagged as 'old' at pouet.net (26.340 Bytes) and recorded it for review. This version shows a "ghosting" effect after the red squares with brighter red pixels. These are not video compression artefacts. The pixels are genuine. What do you think? Amiga Boing Demo Video: http://sharebase.de/files/hmqjBCtAUZ.html Mirror: http://www.egoshare.com/82a4e79af6b4...ngdemomp4.html 5MB - 1min - 50fps MP4/h264/AAC Last edited by NoX1911; 07 January 2008 at 23:20.

08 January 2008, 00:37	#3
NoX1911 2064 Join Date: Jul 2005 Location: de Posts: 231	Someone captured a pic to check the palette. There are slight color variations because of OS3.1 but color positions seem to be intact. Hmm, this really looks like color rotation. Edit: I'll try to recapture the picture with genuine conditions (Kick13) if someone can tell me how to do so? Last edited by NoX1911; 08 January 2008 at 01:03.

08 January 2008, 13:32	#7
heavy noodle Join Date: Jun 2007 Location: europe Posts: 247	take a look at the code hmm...the init and draw globe are called at the start, but not during the mainloop. (real vectors calculated and drawn with mathlib and gfxlib) seems to only move bitmap, poke colors into the copperlist (7 or 8 colors swapping) and play sound too bad Last edited by heavy; 08 January 2008 at 13:47.

01 February 2008, 12:33	#16
Christian Zone Friend Join Date: Aug 2005 Location: Gloucestershire Age: 51 Posts: 218	I remember that the boing demo was re-created on the Amstrad CPC back then lol. I think it was a type-in in Amstrad Action or something (or maybe on a cover tape?) and that it used colour-cycling. As the Amstrad couldn't move a big object around like that I think they used a trick. From what I remember, the CPC could hardware scroll the screen (really fast) like 8 pixels at a time, and the grid gaps were 8 pixels too. So the whole screen (grid and all) was bouncing around, but the grid looked like it was not moving. The same colour-cycling trick was used for the ball rotation. Pretty clever really. Haven't seen it for about 20 years though so my memory is a bit sketchy (goes off to look for it) Edit: I think it was called "Blitter" Last edited by Christian; 01 February 2008 at 18:23.

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07 January 2008, 23:30	#2
ohforf Registered User Join Date: Dec 2007 Location: Germany Posts: 30	LOL... color cycling The Answer is... guess where ? http://piru.dyndns.org/~p/temp/boing.asm

08 January 2008, 03:49	#5
ohforf Registered User Join Date: Dec 2007 Location: Germany Posts: 30	Hmm... using color cycling to fake the Ball rotation would be smart. Moving the Ball by color cycling seems impossible. Must be a BOB. So a legendary Demo that helped selling the first Amigas is in fact a totally fake 3D Engine ? Funny Stuff. I will try to find that in the disassembly... later.

08 January 2008, 09:46	#6
NLS Ancient User Join Date: Apr 2007 Location: GREECE Age: 50 Posts: 758	oh come on people...

08 January 2008, 14:43	#9
viddi Moderator Join Date: Apr 2006 Location: Germany Age: 44 Posts: 4,007	Well, color cycling IS a cool effect, isn´t it?! And it was something new and special in 1985. The A1000 could do it in realtime though.

08 January 2008, 16:04	#10
pmc gone Join Date: Apr 2007 Location: completely gone Posts: 1,596	I agree and, let's face it, I'm not sure the overall effect would have looked any better if it were coded in a more machine resource intensive way. Why make things more complicated than they need to be? - it still looks cool as it is now and especially in '85!

08 January 2008, 17:17	#11
Photon Moderator Join Date: Nov 2004 Location: Eksjö / Sweden Posts: 5,606	Of course it's color cycling. What's mystifying is how they failed to run it full framerate... I guess they used libraries. If I'd do it, the frame loop would take less than one scanline. (< 0.3 % cpu time.)

08 January 2008, 17:33	#12
NoX1911 2064 Join Date: Jul 2005 Location: de Posts: 231	What do you mean by 'full framerate'? It runs at 50fps. That is pal full framerate.

09 January 2008, 20:36	#15
Jope - Join Date: Jul 2003 Location: Helsinki / Finland Age: 43 Posts: 9,864	Heh, if you load it from floppy on a 68000 Amiga and immediately flip WB to back, you can even see it building the bitmap with the wrong palette, it's immediately obvious then that it's color cycling. :-) Color cycle was a really common Amiga trick back in those days. Waves in the sea (Ports of Call), golden shiny logo (Defender of the Crown), heck even the Xmas scene tutorial in DP1 made heavy use of color cycle. :-)

01 February 2008, 13:32	#17
Sune Salminen Dinamáquina Join Date: May 2002 Location: BH/Brasil Age: 49 Posts: 370	I remember seeing the boing demo on the 9" screen of a 68k Mac - In black and white. I'm sure it's out there somewhere.

01 February 2008, 14:52	#18
NLS Ancient User Join Date: Apr 2007 Location: GREECE Age: 50 Posts: 758	The same demo is also available for C64.

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