pouët.net

Realtime?

category: general [glöplog]
Ian: I guess I'm just a old, and all my mates already know, or dont care :)
added on the 2016-06-19 15:02:42 by farfar farfar
If you dump animation data for every single frame from maya or blender and all the demo does in real-time is the shading while stupidly playing the 200mb data blob, knowing nothing about the content, is it still real-time? Is it still a demo? Or is it just a specialized video codec?

For me, what sets real-time apart from pre-rendered is mainly that some or most semantics make it over to the "player". It's a seamless continuum of increasing semantic richness from uncompressed video -> modern video codec -> dumb frame-by-frame animation renderer -> "real" demo -> size-limited productions -> unattainable Kolmogorov complexity limit. When I watch what looks like a physical simulation in a 200MB production, I have no way of knowing if this was rendered by some commercial physics software and dumped into the data file or if it is actually happening now. I find semantic richness interesting and meaningless heaps of data boring, and I'd like to know.

For some effects, you can tell if they are really contained within the demo, e.g. a five minute sequence of multi-million-particle simulation can't be stored frame by frame, so it must be real. For many others, I can't tell and I guess I'd probably consider some recent demos more worthy of the wild or animation category than demo if I knew for sure. A size limit guarantees that what you see on your screen is actually described semantically and reproduced in real-time, instead of being a playback of dead dumb data like a video, which is why I find those categories way more interesting. Basically, all size-limited prods are way "more" real-time than many demos and that's probably the reason people outside the scene get size-limited productions easily and are confused by demos. I'd like something like a 16MB+music+libraries competition.
added on the 2016-06-19 19:22:31 by cupe cupe
Seconding the "small demo" kinda competition. 16mb is about 160 times too much tho, if the song doesn't count.

Then again, sometimes you just have a lot of data even if it's all very "realtime" -- our demo watercolour space had something like 150mb of graphics at an admittedly slightly overkill resolution.
added on the 2016-06-19 20:03:08 by msqrt msqrt
cupe: 4k procedural gfx are far from real-time ;)

If you want to be really strict, any size-limited prod should be using well-defined language and API, otherwise, it's just not _strictly_ size-limited.
There are many examples of "cheating", such as using system resources: true-type fonts, gm samples, recently also standard wallpapers - which was actually funny.
But this is like so old discussion, I'm bored myself in the middle of writing it... meh
added on the 2016-06-19 22:02:11 by tomkh tomkh
tomkh: that is not the discussion we are leading here. Whether taking external data from the system is "cheating" or not doesn't matter here.

The question is: if you ship hundreds of megabytes of precalced data with your demo, is it still realtime?
added on the 2016-06-19 22:24:21 by urs urs
If you don't ship it but precalc it for a minute or two, is that realtime either?
added on the 2016-06-19 22:47:39 by msqrt msqrt
urs: point taken, although video is just an extreme form.

I would even say that the main difference between games and demos is the possibility to precalc.

For example: one of the biggest difference is - you can totally precalculate visibility of objects along camera path. In fact it is the common practice to just enable/disable objects for pre-defined frame range.

The question how far you go with precalc. is just a matter of personal taste and honesty - obviously you can cheat everyone with some full-scene AO/reflections baked into the scene, or video-based HDR environment map, but what's the point? Does winning the party this way will make you happier?
added on the 2016-06-19 23:42:12 by tomkh tomkh
Quote:
I would even say that the main difference between games and demos is the possibility to precalc.

You can fake and precalc a whole lot in games too. And yes, sometimes it's more or less obvious that it generates wrong results (think of pre-baked shadows).
Saga: true, let's not forget Megarace series (or actually maybe it's better to forget), Phantasmagoria or even Alone In the Dark, Myst etc.. Recent games actually rather use in-game engine cut-scenes.
The thing is in demos you can always precalculate a little bit more than in games - up to everything.
added on the 2016-06-20 02:05:19 by tomkh tomkh
Quote:
When people try to explain what demos are to outsiders, they often say that the special thing about demos is that they are "realtime", which distinguishes them from pre-rendered animations. Alas, many demos also feature precalculation! So how does this go together? Wouldn't it be more honest to say that demos originated in the home computers of the 1980s, where CPU power and memory were limited and therefore computer animations could be generated only by relatively small and efficient programs? And that modern demos stand in this tradition?


There is absolutely no exclusivity between those two statements, so why do you inject a false choice between them?

You make it seem like it's one or the other, when in fact it's (blatantly obviously) both. And not only that: one is because of the other.

Ugh, not enough coffee to deal with Adok-stupidity this morning..
added on the 2016-06-20 11:04:03 by gloom gloom
Quote:
For example: one of the biggest difference is - you can totally precalculate visibility of objects along camera path

as if no games do that :)
added on the 2016-06-20 11:59:17 by smash smash
Quote:
The question is: if you ship hundreds of megabytes of precalced data with your demo, is it still realtime?


citation needed. got an example of this in a real PC demo? (of course everybody knows about those dirty amiga precalcers already)
added on the 2016-06-20 12:00:54 by smash smash
hurray for point level animation! ;)
more i read.
realtime doesn't matter.
just one effect/style/approach.
if we start to judge how much bass a track has it fast becomes a sub genre.
added on the 2016-06-20 12:08:49 by 1in10 1in10
Doesn't really matter to me. I consider any runtime that actually runs after executed and displays anything and/or produces audio. Whether it does it via realtime calculation or data file streaming is a matter of category definition, such as by compo size limit, theme, platform, etc.
added on the 2016-06-20 14:54:29 by visy visy
also one thing that strongly factors for the "demo-like" experience is the hack value of the production (or, "worksmanship" of the demo), not just purely the personal aesthetic experience of demo. Even a video player production can strongly exhibit this, like in "Bad Apple!"
added on the 2016-06-20 14:57:12 by visy visy
Quote:
citation needed. got an example of this in a real PC demo? (of course everybody knows about those dirty amiga precalcers already)
Well not hundreds, but I guess we once shipped like 90mb or so of precalced particle animations because we could and it looked cool.
added on the 2016-06-20 15:54:23 by numtek numtek
For me it's about limits.

If someone draws a book with only a pencil but it looks amazing there's an appreciation that they had some limits (see Chris Van Allsburg).

So demos have the limit that the scene has to be created from scratch 10-60 times a second. Some demos add the limit of size (256b, 1k, 4k, 64k).

I find shadertoy examples both amazing and frustrating. Amazing! You drew that from math! Frustrating! My computer is drawing something at 1fps it could do a 200fps with more traditional techniques. I think that latter part is what lots of outsiders think of demos. Movie effects companies make amazing visuals with no limits so why limit yourself. But it's those limits are what make it interesting. You did THAT with both hands tied behind your back? Wow!
added on the 2016-06-20 17:19:12 by greggman greggman
For me it's all about how many horses you can show as quickly as possible!

I'd love a 64 Horse category, where you need to show 64 horses at least somehow!

Horses man! Horses!
added on the 2016-06-20 17:28:27 by okkie okkie
The scene is all about fitting 3 horses in a citroën 2CV, although... your mileage may vary.
Horsepower!
added on the 2016-06-20 17:57:28 by Tolle Tolle
it good to see people have different expectations from demos, that way there's still many opportunities to impress people in different ways and many opportunities to do creative things! be it in 200mb, 16mb, 64k or horses.
My next demo will be playing a .mp4 video using Unreal Engine.
added on the 2016-06-20 22:25:53 by Soundy Soundy
who cares? the beauty of peer review is that your peers will review your video playback in unreal engine and deem it shit.
added on the 2016-06-20 22:37:47 by farfar farfar
Quote:
the beauty of peer review is that your peers will review your video playback in unreal engine and deem it shit.


except if your peers are these new social justice dummies who judge your work based on what you said to someone.
so, this shit video playback demo could be a winner. just lick butt and say nothing non pc.
added on the 2016-06-20 22:44:12 by 1in10 1in10
Video playback is ok as a demo, if the scene accepts it. It's all about the people and their opinion. If it's entered and accepted in a demoparty compo, then it's definitely a "prod". The people decide. Rules and logic don't decide.
added on the 2016-06-20 23:29:35 by yzi yzi

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