On 18/08/2014 09:19 AM, Stephen wrote:
> On 18/08/2014 07:58, scott wrote:
>> The balls moving like that made me remember back to those computer demos
>> in the early 90s, they always seemed to have at least one section with
>> 10 or 20 balls moving about in interesting patterns. Of course back then
>> the balls were usually just 2D sprites and the screen resolution was
>> 320x200 or something ;-)
>
> That is the one. I am sure Andrew posted an animation of that years ago
> as a homage.

About 2 years ago, in fact. ;-)

I first saw this trick on the SAM Coupe (no, I cannot find any mention 
of it on Google). I and my siblings were astounded that the computer 
could animate millions of balls like that. (In the demo, it runs as long 
as you leave it, with a ball counter in the corner constantly counting 
up. When you press a key, it switches to the next pattern.)

The "trick" is that it's not actually sprites at all. I saw a demo like 
this on the Amiga, using Bliz Basic. And it turns out, all it does is 
this: There are 16 framebuffers. It draws just ONE ball onto the next 
framebuffer, and then switches that to be the current one. That's all it 
does. It's only rendering 1 ball per frame, but because each framebuffer 
still has all the previously rendered balls on it, and there are 16 
framebuffers constantly switching, it LOOKS LIKE the computer is 
actually animating millions of balls, all at once!

I, of course, REALLY AM animating several hundred spheres, in actual 3D, 
with full global illumination. At about one frame per hour. :-P

Makes you think, though... Remember that browser-based GPU unbiased 
renderer demo a while back? If I could somehow utilise that, the entire 
animation could be done in mere *hours*...!

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