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Tech and Homebrew => Turbo/PCE Game/Tool Development => Topic started by: Dicer on June 20, 2016, 10:20:29 AM
Title: Demoscene, how much of this f*ckery could the PCE do??
Post by: Dicer on June 20, 2016, 10:20:29 AM
Ah the Demoscene, making hardware do all sorts of neat stuff, the peak for me were the C64 and Amiga Demoscene, which used a lot of the same trickery to achieve some mind blowing visuals for the machines they were running on.
How possible would it be to pull some of this visual trickery on the good ole PCE, I know there are a few examples, but I think it could go further.
Best Amiga Examples.
Hell even some Atari 2600 Demo action
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: Arkhan on June 20, 2016, 02:19:04 PM
Some of those 3D effects, and the FMV like stuff is possible. It's just out of place on PCE.
Chris Covell has done some similarish stuff.
SOME of the scaling/rotation stuff would be a bit of a pain in the ass.
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: ccovell on June 20, 2016, 02:29:03 PM
Cool effects can be done, but things like filled polygons & rotation... the PCE cannot do very well. A lot of the transparency, cut-out, stretching effects that the Amiga pulled off by shifting around bitplanes & playing with the scroll registers can be done on the PCE with few problems.
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: Bonknuts on June 20, 2016, 05:12:10 PM
Demos pretty much boil down to how can you exploit as system (cpu registers, hardware, how it all interfaces, amount of ram). Demos tend to build or decompress items into ram as well (setup prescaled frames during runtime VS stored format) - the PCE doesn't do so well in that area if it's a hucard platform (8k of ram). Special effects can be done on the PCE, exploiting the planar format, but you need fast bandwidth and that usually means storing graphics in ST1/ST2 embedded opcodes (bloating its size). Planar sucks for fine pixel placement, so you need 8 offsets of images (couple that with embedded bloat). Some really interesting things can be done on the PCE, but it's starving for ram for these kinds of things.
The PCE hardware is also pretty straight forward, so not a whole lot of "unique" things can be done with it. You basically have to really think outside the box and come up with your own new effects. Watching other demos helps gives ideas, but prepared to write some really crazy code (complex, convoluted, etc).
There are a handful of hardware tricks you can do on the PCE that emulators don't handle. They aren't super fantastic, but the trick is finding something that exploits them. I haven't tested it, but I have a theory about how to gen lock the cpu to the video display inside an hsync interrupt (which could be useful for a couple of effects). There's the undocumented VDC regs 3 and 4, which use the VRAM read register to do weird things (it's a bitmap of the 16bit map that sets thing on/off on the VDC). Half height sprite mode (which can be changed per scanline to do vertical warping stuff on the sprite layer). 128x128x16color byte bitmap mode (with free transfer/erase via vram dma). Or a 64x128x256color byte bitmap mode (128x128x256color for SGX). The bitmap modes can be horizontal or vertical sequential - allowing for a fast raycaster engine. Using the VCE to do stretch pixel interference on screen (in whatever patterns). Stuff like that.
I started doing some demo effects and saving them individually, but never got around to putting it into a fancy demo. Presentation is everything, and while I can code and make crazy effects... making/designing great looking demos isn't my thing.
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: touko on June 21, 2016, 04:17:21 AM
Mooz did some nice 3D effects on PCE . https://www.youtube.com/watch?v=Rw0oNsbWjpI
http://www.pouet.net/prod.php?which=62012
And also nice chiptunes by octapus ..
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: Bonknuts on June 23, 2016, 11:00:41 AM
So.. when are we making a demo?
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: crazydean on June 23, 2016, 01:39:15 PM
I'm a bit confused by all this. I'm not very familiar with the Commodore or Amiga, but the 2600 demo just seems unbelievable. I haven't seen any 2600 game that looks remotely close to anything that was on the demo, not to mention the music. So, why is that? Why were there no games that looked or sounded that good?
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: Sadler on June 23, 2016, 02:39:14 PM
That's the point :D Adventures of Batman & Robin is close.
Edit: on the Genesis, which I guess doesn't have much to do with the topic.
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: Dicer on June 23, 2016, 05:27:18 PM
I'm a bit confused by all this. I'm not very familiar with the Commodore or Amiga, but the 2600 demo just seems unbelievable. I haven't seen any 2600 game that looks remotely close to anything that was on the demo, not to mention the music. So, why is that? Why were there no games that looked or sounded that good?
Demoscene basically "codes to the metal" pushing the very limits of the machine, and even somehow breaking them...they can do this because they aren't programming in logic or hit detection or anything a game needs. It's always been fascinating to see how far they can go, PC demos aren't as interesting unless they are the size restricted ones (ala 4k 64k comps) because what they accomplish in a space smaller than a blank word document is utterly amazing sometimes.
4kilobytes, insanity....
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: Arkhan on June 23, 2016, 09:57:20 PM
The one thing I could never stand about demos is when they put dumb scrolling text as effects are occurring.
They always read like some announcer/commentator at a dog show or gymnastics event.
I'm a bit confused by all this. I'm not very familiar with the Commodore or Amiga, but the 2600 demo just seems unbelievable. I haven't seen any 2600 game that looks remotely close to anything that was on the demo, not to mention the music. So, why is that? Why were there no games that looked or sounded that good?
Although special effect techniques are much more commonly known and shared today, the main reason is rom size.
There are homebrew games like that and the 2600 even has Super Mario Bros now.
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: touko on June 24, 2016, 02:31:01 AM
PCE or SGX ?? Some ass to kick in the titan team ?? :mrgreen:
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: Bonknuts on June 24, 2016, 05:32:18 PM
Meh.. I don't care about rivalry or competition. I just wanna make great stuff on the PCE. That said, the Titan demo was OK. Genesis fans loved it, so I guess that's what counts. Kinda expected quite a bit more for such a popular platform though.
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: touko on June 24, 2016, 08:07:17 PM
It was a joke :wink:,just for fun,not for starting a demo war .
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That said, the Titan demo was OK. Genesis fans loved it, so I guess that's what counts
It's a very enjoyable demo, with good music and very good transitions, the effects parts it's the standard parade,but well paced.
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: touko on July 18, 2016, 12:18:08 AM
That's an effect you can do on SGX : https://www.youtube.com/watch?v=b-6VxCA-4Z0
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: ccovell on July 18, 2016, 12:32:19 AM
No, the above effect you can easily do on the PCE with the background and overlaid sprites... or with a bit more difficulty with just the BG and dynamic tiles.
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: touko on July 18, 2016, 01:57:59 AM
No, the above effect you can easily do on the PCE with the background and overlaid sprites... or with a bit more difficulty with just the BG and dynamic tiles.
Seems a little bit difficult to do the same on PCE without any compromise .
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: elmer on July 18, 2016, 03:38:52 AM
Seems a little bit difficult to do the same on PCE without any compromise .
Really, why???
Sprite layer for the foreground/text, and the wave done in the background layer with hblank interrupts.
Am I missing something that it was doing?
That may be the least-talented "demo" that I've ever seen for the Amiga.
<EDIT>
Perhaps I am ...
I guess that you're thinking that the halfbrite on the text layer is going to be the problem.
I'm not immediately sure how I'd do that on the PCE, but I'm guessing (at the moment) that it could possibly be done with sprite-priorities. Touko ... is that the bit that you're thinking of that would need the extra SGX BG layer?
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: touko on July 18, 2016, 04:24:30 AM
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Sprite layer for the foreground/text, and the wave done in the background layer with hblank interrupts.
Yes you can do that of course, but your sprite bandwidth should be the limiting factor here (for text and others stuffs) . But i don't see how to do the transparency effect . :-k Amiga works in 320 pixels.
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Touko ... is that the bit that you're thinking of that would need the extra SGX BG layer?
Not only that, you could use the VPC to fake transparency, coupled with some hblank interrupts it's easy to do(and almost free),and you have all your sprites available for some other stuff .
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: Bonknuts on August 03, 2016, 08:49:32 AM
I could do it without sprites, on PCE. And with two more sine waves with overlapping transparency. :)
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: ccovell on August 04, 2016, 03:19:56 AM
No, the above effect you can easily do on the PCE with the background and overlaid sprites... or with a bit more difficulty with just the BG and dynamic tiles.
Haha. I only say that because I had a similar working demo effect, but with overlapping moore-spiral effect and with translucent text over it.
OK, you guys shamed me into actually thinking about how it could be done just like that video (or better).
I get it now. The sine-wave and semi-transparent text is (relatively) easily achieved by writing into separate bitplanes within a BG tileset and then organizing the palette properly.
If you're doing that in the BG, then there's no problem in making the screen 320 pixels (or 512 pixels) wide ... and then doing multiple layers and also something else with sprites.
Neat!
But ... what a fraking waste of programmer time! #-o
It also makes me even less impressed with the "demo" video and the crew at "insane" than I was before.
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: Bonknuts on August 08, 2016, 11:02:25 AM
Hey now... I have a some demos effects stashed away for a demo... one day. Can't be showing them willy nilly without presentation ;)
That's going to be one heck of a demo when you finally get the time/desire to work on it! 8)
Here's the main problem: Demos need to have good design and presentation. While I can do cool FX - art, design, and overall presentation is not my forte. I mean, I can wing it but it's best of I could collaborate with someone else on this. A team, actually.
Just look at Titan demo on the Genesis/Megadrive. It's not really technically impressive IMO, but it looks great. Nice artwork, music, animation, flow, etc. And that's what matters in the end.
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: Arkhan on August 11, 2016, 07:37:34 PM
Demos don't need good design and presentation.
All you need is a eurowank dance tune, scrolling text with you rambling about what's on screen + shout out to your peeps, and then some flashy effects framed by a static border that looks cool.
lol
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: Dicer on August 12, 2016, 01:35:02 PM
All you need is a eurowank dance tune, scrolling text with you rambling about what's on screen + shout out to your peeps, and then some flashy effects framed by a static border that looks cool.
lol
You just nailed about 98% of old school demoscene...
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: ccovell on August 12, 2016, 01:59:47 PM
You just nailed about 98% of old school demoscene...
The keyword being OLD school. If you release more than one demo with just a logo and a scrolltext, you'll get very low marks from current demosceners.
That's why I made the distinction...
A lot of the trademark "techniques" are still in play for older machines, but the way they are pushed and presented these days are a big step up.
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: touko on August 13, 2016, 07:31:09 AM
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Just look at Titan demo on the Genesis/Megadrive. It's not really technically impressive IMO, but it looks great. Nice artwork, music, animation, flow, etc. And that's what matters in the end.
i agree, but it's not so easy to do some of the standard PC's demo effects like seen on C64, because you can doing some incredible mid scanlines's stuffs with timed code.
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: elmer on September 20, 2016, 06:30:32 AM
Bonknuts:
I just saw Stef's Genesis version of the Bad Apple demo, and saw on the forum thread that you were posting about doing a PCE version.
Was that ever finished? If not, is it still work-in-progress, or has it been abandoned?
Another Genesis thread with interesting compression ideas: http://gendev.spritesmind.net/forum/viewtopic.php?t=1489
I didn't finish it because 2.5megs (SF2 mapper) would have been too little storage for both audio and video (compared to the other systems; Genesis and SNES). I didn't want to give the wrong impression of the PCE. The video compression I was working on, was turning out quite well though.
Maybe we could re-visit this idea since the new TED allows up to 4megs. The PCE can do 8-10khz software decoding of ADPCM pretty easily (I modified Sarsie's source code); it could be even faster if the PC side encoder handled over flow instead of the PCE playback driver handling it via saturation.
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: elmer on September 20, 2016, 08:31:26 AM
I didn't finish it because 2.5megs (SF2 mapper) would have been too little storage for both audio and video (compared to the other systems; Genesis and SNES). I didn't want to give the wrong impression of the PCE. The video compression I was working on, was turning out quite well though.
That makes sense ... IMHO there's little point in doing it if it can't look as good as, or perhaps even better than, the other 16-bit machines.
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Maybe we could re-visit this idea since the new TED allows up to 4megs.
Yep, that might be enough for the video.
512x224 video would be lovely, if it could fit. :wink:
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The PCE can do 8-10khz software decoding of ADPCM pretty easily (I modified Sarsie's source code); it could be even faster if the PC side encoder handled over flow instead of the PCE playback driver handling it via saturation.
The PCE was the 1st CD-ROM console featuring full CD-AUDIO playback, way before the Genesis and the SNES even appeared.
I don't understand why you'd consider ignoring that and feature low-quality 8-10KHz ADPCM audio instead of using the platform to it's strengths.
<EDIT>
Or to put it another way ... the Genesis and the SNES both have separate audio-processing chips, so why not use the PCE's?
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: Bonknuts on September 20, 2016, 08:37:09 AM
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I don't understand why you'd consider ignoring that and feature low-quality 8-10KHz ADPCM audio instead of using the platform to it's strengths.
Because the running mentality was/is that it needs to be all cart/core system to be valid. If I had used the CD platform, it wouldn't have been considered "impressive". The same reason a SegaCD version wouldn't have been that impressive (general consensus). 8-10khz was to keep the compressed audio small enough to fit into 4 megabytes, and to keep the cpu resource down in case the video decompression scheme really worked the cpu resource.
There's this mentality that "oh, a CD system is just streaming video/audio.. no big deal". Well, technically, the cart is just doing the same. But the cart has storage constraints, so I guess that makes it more impressive.
So it was more of a "play by their rules" sort of game. That, and being a cart/hucard platform - you have a wider range of PCE fans who can run the demo.
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: elmer on September 20, 2016, 09:04:18 AM
Because the running mentality was/is that it needs to be all cart/core system to be valid. If I had used the CD platform, it wouldn't have been considered "impressive". The same reason a SegaCD version wouldn't have been that impressive (general consensus).
That's just BS!
For a start, the PCE DUO is a "core" system (at least in my book), and the original PCE system was always designed to have a CD-ROM (as has been discussed-to-death in other threads here).
The Sega CD was an afterthought, and anyway, it's so crippled by the VRAM transfer bandwidth from the 2nd CPU that it's not like you get great video out of it as a CD streaming-platform anyway, and there's no super-fast connection to the ROM (IIRC) for it to read everything from there.
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There's this mentality that "oh, a CD system is just streaming video/audio.. no big deal". Well, technically, the cart is just doing the same. But the cart has storage constraints, so I guess that makes it more impressive.
Exactly ... and a cartridge has an exponentially higher bandwidth than a CD, so you're just trading one limit for another.
As a programmer, you already know these things.
You also know (I assume), the huge differences between the primitive 4th-generation console CD-ROM hardware, and the 5th-generation console CD-ROM hardware (with video-streaming designed in from the start).
If you limit yourself to the pre-conceptions of idiots, then you just sink to their level instead of showing them that there is a bigger world out there.
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That, and being a cart/hucard platform - you have a wider range of PCE fans who can run the demo.
I get the desire for an audience ... but then why not limit yourself to the standard 1MB ROM configuration and play to all of the PCE's weaknesses?
Title: Re: Demoscene, how much of this f*ckery could the PCE do??
Post by: Dicer on September 20, 2016, 10:31:29 AM
The 2600 has bad apple the TI calc has it as well, I say cram it into a tight of a space as possible, if you are going over the "usual" space then it's kind of defeating the purpose of putting on the hardware IMHO, do the best with the space that would be allotted, just my .02 on the matter.