Demos using a GFX mode please !

[mdwh2]

1) When Amiga demos will be GFX mode compatible ? I mean, I would like to see some demos in UAE using the P96 emulation, i.e. in full screen mode. But as long as all (all ?) demos are AGA, they can be viewed in window mode only.

I'm not sure how you mean - WinUAE at least can display non-RTG stuff in full screen mode (Display tab, tick 'Full Screen'). And I have seen a few RTG demos around, at least.

(Is anyone else unable to log into amiga.org using Opera btw?)

[mdwh2]

darkcoder wrote:
And because this extra requirment you introduce, you need to specify an hardware
which gives you some limits and you have to reach the limit of the hardware by coding. If you don't fix a limit to the hardware (and with RTG you have no limit) it's useless to use coding, just use gfx applications and an hardware powerfull enough.

It's true that when comparing the skill of coding a demo, one needs to look at the hardware it runs on, which is easier if you have a fixed level of hardware. But still, even on the PC, I think it can be appreciated that some games/demos/engines are better than others, either in terms of speed or features. I'm not sure what you mean by it being useless to use coding. And demos were popular back in the days when the Amiga's CPU speed was not fixed/limited.

@Karlos you gave a good point. However, I still don't see the sense of RTG demos for the following argument: with RTG you can use many differeent gfx boards having very different features (which IS a good thing for everything but demo-coding). If you want a demo running on all the gfx cards, you have to consider the slow ones and you don't use the most powerful features of the others. On the other hand, if you say "this demo requires ATI Radeon card" then you are forcing the use of a particular hardware.

Or you can say "this demo requires a graphics card that supports x feature". You don't have to choose between either supporting all cards, or only supporting one particular brand.

So IMHO, with these cards there's nothing left to code. For example, a 3d demo could be something like this (I am actually NOT a RTG coder so I invent function names)

First of all, as others have said, making something RTG compatible doesn't mean you have to use the card's 3D features.

I admit that I haven't kept too up to date with graphics card features in the last couple of years, but I don't think they do everything for you. Generally, they'll do things like the rasterisation for you, but other things such as hidden surface removal, particle engines, realistic physics still require coding. In your example of code, there is no magic ComputeVisibleSurfaces function (well you could send everything to the card anyway, but then it'd be slow..)

Of course yes, a simple scene done in OpenGL requires little skill, where as it's a lot of work to do in software, but more complex stuff takes a lot of skill even with OpenGL.

I understand that things like software rendering (which I have done) and AGA 'hardware-banging' (which I haven't) can be fun and require skill - but it can also be that when utilising 3D hardware.

why use programming at all? Just use Photoshop and concentrate your efforts just on the aestetical aspect.

Well some people do do that, they're called artists;) But some people prefer coding - and some of those prefer working with 3D hardware and exploring programming of areas other than low level things like rasterisation.

[mdwh2]

darkcoder wrote:
which people? If I am right since 1986 about 6*10^6 Amigas were sold. All of them can run OCS stuff.
I think at least 2*10^6 AGA Amigas exist. All these can run AGA stuff.

AIUI, the problem is not whether Amigas come with Amiga chipsets, but that either a TV or 15kHz monitor is needed. Unfortunately things like multisync monitors are rare (are there any still in production? I remember trying to get hold of one in 1998 with no luck), and things like scandoublers are expensive (if they work at all.. mine didn't), so I can imagine a lot of people preferring to use a standard monitor with their gfx card, and forgetting about chipset output (of course, it's difficult to know how many people actually do this).

[mdwh2]

darkcoder wrote:
>In your example of code, there is no magic >ComputeVisibleSurfaces

usually gfxcards have z-buffer, so you don't need hidden surface removal. Ok,
of cource t's better if you filter objects completely outside the picture.

In general, it's a lot better. For simple scenes (like a few spinning cubes), using the Z Buffer only will work fine, but larger more complex scenes will generally benefit from using things like BSP trees to remove polygons that aren't visible. Whilst using OpenGL and 3D cards in some sense makes writing any given 3D demo (or indeed, a game) easier, that just means you can write something more complex, and spend time programming other areas that OpenGL doesn't take care of.

I can see your points that you make; I guess different programmers enjoy programming different things:)

But now. Let's say I decide to do some 90% optimized code, for example to do a
radiosity algorithm. There I don't need a custom architecture, I could do that
with RTG. But I can do 90% opt code also with a PC. So way use RTG "new amiga"?

I guess I'm not the best person to answer this in that most of the 3D programming I've done has been on Windows. But I have ported some of it to AmigaOS (albeit using WinUAE). Partly because I enjoy using and programming AmigaOS (and just because I want to use RTG doesn't mean I need or want to have the fastest CPU available); partly because there seems to be less in the way of 3D engines on the Amiga where as they seem to be plentiful on Windows, so there's possibly more chance of interest if I ever get round to releasing anything:) And partly for the fun of porting to a different OS.

You wrote that you do software rendering, I don't understand if you mean that
you code raytrace algotrithms or that you use software produced by others.

I mean in the sense of 3D "polygon based" engines, not raytracing, without using anything like OpenGL.

[mdwh2]

Anyway making a demo for a 800mzh system and to IMPRESS some one, how is that possible??
by good textures??? , who will set the standard??? , its been 8 years on pc now and i am not impressed.

Just because it's a fast system doesn't mean it's not possible to write impressive stuff. The latest hardware is still a *long* way from making it possible to render scenes as realistic/impressive/complex as you want, *and* without requiring much skill on the part of the coder.

A C64 coder could ask how could anything on an A1200 be impressive, since "any" demo could be done with ease on an A1200. The point is that you don't write C64-level demos on an A1200, you write more advanced stuff.

Fair enough if you enjoy (either from a programmer's, or a viewer's point of view) the level of demos that are common on 680x0/AGA Amigas, but that doesn't mean there aren't others who are interested in pushing the boundaries on more advanced hardware. I still get impressed when I see modern graphics engines running where as there's only so much interest the likes texture mapped cubes and tunnel effects can create for me.

I don't believe making more realistic or impressive graphics is simply a case of increasing the texture resolution; it requires work from the programmer too.

As for who will set the standard, I don't see how that's any different. It's slightly harder if one demo runs better on one machine, and another runs faster on another-  but it's not like you run them on different machines when comparing.

anyway to all who still thinks that an 800mzh demo can impress yo, well OK check all ppc demos at the amiga today, and please tell me which of theese that is impossible to do on a 68k system,
on top of all i have only seen 2 really fast ppc demos on amiga , the whole point why so few went ppc with their demos is basically because of this,
the p5 ppc's are really crap and infact only (MAX) 3 times faster than a 68k system,

Presumably the AmigaOne will be quite a bit faster than the current PPC Amigas though. And the question more related to this thread is probably What AGA demos can't be done on a graphics card.

WHAT makes a good demo...GOOD code or good textures or high RES ?.

Good code. Which is possible to show off whether on a PPC gfx card Amiga or PC, 68k/AGA Amiga, or a Vic 20. Which is possible whether the machine can be upgraded or not. Whether the graphics chips sit on a card or live on the motherboard.

What would your response be to a C64 demo coder who put your arguments back towards you?

[mdwh2]

Regarding optimisation, I think it's worth remembering that there are different styles of optimisation. Doing things like hand optimising in assembler, trying to optimise every single low level instruction, and using things like fixed point arithmetic are a lot less likely to be useful on modern machines, than something like the A1200. But at the same time, there are still other ways to worry about optimising (usually more related to the algorithms being used), so it's not like one can get away with writing unoptimised code. I guess different programmers will find different things enjoyable.

lempkee wrote:
its all about making a 3d engine, and i dont find 3d impressive at all (except for maybe in games)

*nods* Well I guess this is the point; different ppl prefer different things, and there are those who find 3D stuff impressive.

since 1995 pc have been mixed into amiga demo compo's , please tell me why amiga have mostly won or got very good rankings compared to the pc ones,
and the pc had specs that was double or tripple (or like now x20) and still the amiga ones win? , also they dont say if its AMIGA or PC , they quitted that a long way back.

Presumably they are rating based on creativeness or originality or interest of the effects; if they don't know what machines it is running on, they can't be rating it on how well it's been optimised (well, unless all the PC entries were completely crap;). Indeed, if competitions can be held with demos running on differently specced machines without the viewers knowing which machine each was running on, then surely this further proves the idea that you don't need a single fixed standard platform to run demos on.