pouët.net

@Luis: THANKS!

@rasmus: No rubber != jelly. Basically, for rubber you keep N (the bigger the better?) frames of your basic rotated cube in buffer, and you draw line X on screen as line X of Xth buffer, and that's it you have the rubber effect at no cost!

@tomcat: IFS stands for Iterated Function System iirc, the result is (often) a kind of fractal. Wikipedia is your friend: http://en.wikipedia.org/wiki/Iterated_function_system

Some OLDSCHOOL shit off the top of my head that wasn't mentioned:

- Kefrens / Keftales bars
- Border/Sideborder tricks (maybe too hw specific)
- Mosaic
- Lissajous
- VU meters (they were everywhere)/Animated VU meters (Red Sector Megademo)
- Parallax scrolling (Usually landscapes, like Dutch Breeze/Shadow of the Beast)
- Musical Band (animated band plays instruments in time to music)

Jeez, that last one takes me back :)

Think I did not see these in the list:
- LED scroller (scroll made of small "leds" that are on/off)
- Background patterns distortion (using either repeated animated blocks or color palette changes per scanlines, also used for drawing vertical distorted mini scrolltexts)
- Vector ball scrollers
- reset demos
- loading/decrunching screens
- single line gradient effect (often used on amiga on demos that looks like 16:9 aspect ratio)

I see it as normal flat polys with rasterbars in them. Stenciled polygons usually have a pattern not not just bars.

and the mandatory:
- strobo
- random putpixel aka noise
- raycasters
- sphere/pixel collision+physics (e.g. in iguana's inconexia or the pixels in fc's fishtro)

and shadebobs, never forget shadebobs!

zoomscroller (as a special case of the limited-number-of-unique-scanlines zoomer)

3D with single rotation axis (usually X): scanlinecubes (with or without texture), rotating rasterbar structures, dot objects with high dotcounts

"cube grids" (meaning the kind where only one cell of the grid introduces new frames of the rotating object, and other cells duplicate earlier frames)

favoured objects not yet mentioned: platonic solids, sierpinski pyramid, elite ships, cylinder

- kaleidoscope

They could just have drawn the stencil pictures to look like rasters bars.



The term Snurkel scroller comes from this demo: http://pouet.net/prod.php?which=8034, it's basically a bob scroller (like the one in this demo: http://pouet.net/prod.php?which=15254) but rotating on Z with precalculated rotating chars, the first one appeared in this demo: http://pouet.net/prod.php?which=26328 but the term is coming from the defjam/silents demo which was more known/popular.

There's also space scrollers (like this one: http://pouet.net/prod.php?which=31065) which are scrolltexts made from a 31 colors triangle mask where mask lines and colors (coming from a bitmap font) are selected/modified at each scanline acccording to some sine tables. I believe this triangle/copper technique was first made by Mr. Mega Mind in dexion's megademo: http://pouet.net/prod.php?which=7855 (top/right on the screen shot).

Vertical raster bars (usually wrongly called kefrens bars) were first made by metalwar of Alcatraz (center bottom on the screenshot: http://pouet.net/prod.php?which=14533) and not Detron of Kefrens, it's using a trick with the raster beam, negative copper modulos and 1 lines bobs waving on sine table.

Twisters are a bit like space scroller except they're not using a triangle mask but a rotating one, first appeared in: http://pouet.net/prod.php?which=981.

etc.

Yes, but that seems completely idiotic, as copying data is slower than filling one colour :)




The Cuddly demos (Youtube) reset screen also have a snurkel. Also April 1989. Which was first?

Wow, I can't believe I didn't know what a snurkle scroller was -- what a neat effect for only a memory cost.

that list make me sad, you forgot all the essential demo effects :(

-> GLENZ VECTORS
-> DRAGONBALL
-> JELLY CUBE

please watch Melon Dezign's "Human target".

what list :p glenz and jelly were mentioned...

Interference (moving circles) is also another popular effect, first seen in Mayhem's Paracetamol demo: http://pouet.net/prod.php?which=14814

optimouse: I thought it was/is just a blur of the original scene with grayscale filter and perhaps some contrast adjustments and a simple additive blending over the original demoeffect/scene, but correct me if im wrong.

tomcat:
Ive seen it in Digital Matrix / Legend Design. hmm. cant remember if it was in Second reality though. I think maybe the correct name is tube-starfield. but i think its called circular as well. (not sure though).

what is fluffy and wolfram?

UnOfficial Demo Effects listing from 197x - 200x:
--------------------------------------------------------------------------------
AI: Boids, Cellular automaton, Game of Life
Bars: Copper-, Raster-, Kefren/Keftale-, Parallax-, Alcatraz-, Vertical-,
Rotating-bar(s). Coppershade. Rastersplit. Border/Sideborder-tricks.
Blur: Horizontal-, Vertical-, Radial-, (Fake)Motion/Feedback-, Zoom-blur.
Bobs: Shadebobs, Vector-bobs/balls (+/- unlimited), Starbobs
Chess: Chessplane, Chesswaver, Chesszoomer
Cube: Fire, Rubber(Scanline/Slit scan), Jelly cube, Texture-feedback, Grids
Feedbk: Fire, Water, (fake)Motion blur, Zoom blur, Mosaic, Plasma,
Snow/Sand effect, interference (xor effect)
Fractal:Mandelbrot (+/- zoom), Julia (+/- morph), Quaternion Julia
Freedir:Freedirectional-planes/tunnel/sphere/wormhole/warp
(aka plane deformations).
Glow
Hypnoglow
IFS: Iterated function system fractals, Trees, Flowers
Image: Zoomer, Rotozoomer, Precalculated Image Distortion, 360 Panorama,
Sine-wave distortion logos, waving/tech tech, Lens
Interp: Linear-, Bilinear-, Trilinear-interpolated image (+/-) zoom.
Lensflares
Meta: 2D/3D-Meta-balls/cubes/toruses/tunnel/blobs
Palette:Alpha Blending/Fade-in/out, Crossfade, Melting, Cycling/Rotation
18-bit color.
Pixel: Dotballs, Noise(interference), 3D-Dot/Vector-landscape
Plasma
Precalc:Wormhole, Image Distortion, 2D Bumpmap, 2D Tunnel
Raycast:Doom-walls, Water reflection
Raytracing
Rotozm: XOR-, Image-, Chess-rotozoom
Scroll: Parallax(Horizontal/Vertical)-, Sine-, Star Wars-, Hard/Soft-, Snurkel-,
DYCP-, DYPP-, DYSP-, FPP-, BOB-, LED-, Zoom-, Spline, Multi-,
Zoom-scroller(s).
Sine: Sine-flag/plasma/scroller/distortion
Sound: VU-meters, FFT, Softsynth
Splines:Spline-ball/scroller
Sprites:Multiplexed, Infinite, Spriteborder effects
Starfld:Circular/Tube-, 2D(Vertical/Horizontal)-, 3D-Starfield.
Twister:Scanline, Voxel
Vector: Vector-dots/balls/morphing, Hidden vectors, Gradient, Distortion,
Particle-physics
Voxel: Voxel-scape/landscape/tunnel/sphere/torus/polygons/twisters.
3D: Ribbons
3D Object (Blenk, Glenz, Stencil, Metal, Wireframe, Dot)
3D Object Shading (Texture, Environment, Bump, Gouraud, Phong, Lambert,
Flat)
Techniques:
Adaptive subsampling, Gridexpander,..
--------------------------------------------------------------------------------

the listing and also some greets can be found here:
http://www.home.no/rudibs/dox/demoeffects%20list.txt

Likely only on Amstrad CPC, but :
* Split border
* Vertical screen splitting and whatever fun things can be done with it (changing the display pointer right in the middle of a line messing with the video chip)

* Flipping (showing two different images every other frame to make it look like there are more colors)

Dots :
* delay dots
And for that matter, any "delay-" effect involving actually color cycling and/or double buffering (delay-rotozoom like in RTS http://pouet.net/prod.php?which=1195 , …)

Sound : (on atari ST, CPC, Spectrum) : Sidvoices, Syncbuzzer,and whatever similar things

MIssing the Rewind button (it is realtime right) like in Lost Signal
http://www.pouet.net/prod.php?which=54945

a good example of a rubber cube is on chiptune.com/
the "twist v3"

theres some fx on there too


dont know their proper names but (some/most/all maybe have been mentioned)

parallax scroller (sotb)
water fx (waves)
copper bars (copper)
zoom scroller (greetings)
circular starfield (starfield)
plasma (plasma)

hypnoglow& Adaptive subsampling are newschool.

I'll add:
"wobble"

@ruderudy: thanks for your work!

Now someone courageous to add a snapshot/explanation behind every effect?

In http://www.home.no/rudibs/dox/demoeffects%20list.txt:

As far as i know it's only a x=sin(alpha+?) / y=sin(beta+?) curve. Wikipedia is your friend... They were used a lot for sprites/dots curves.


Maybe you can regroup them with splines under a curve category.