/vr/ - Retro Games

>>3075039
Layers anon

OP is a retard.

>>3075043
Can you elaborate further?

>>3075078
Photoshop mask.

>>3075078
OP here. I meant the original image to be rhetorical, but >>3075052 >>3075043 don't give the effect enough credit.

The SNES has 8 different background graphics settings, modes 0-7. You have surely heard of mode 7. What you might not know much about the other modes. In this case mode 1 is used, in which the programmers had access to 2 16-color/tile backgrounds and 1 4-color/tile background layer. SNES games are composed of building up layers on top of each other to make a full screen image.

Super Metroid uses mode 2 where BG1=foreground, BG2=background, BG3=overlay (water,lava,mist,etc). When the X-ray scope is used, BG2 is set to a copy of a computed "revealed" foreground layer. To cut a wedge shaped area simulating the scope, a technique called windowing is used to throw out the foreground within the wedge, while the shape of the wedge is modulated per scanline using a technique called Horizontal Direct Memory Access (HDMA), which is just a fancy way of saying they updated some memory (here the window) every scanline. The effect is further refined by a constant color subtraction to darken the atmosphere using HDMA too.

It's actually a really clever use of the tools they had available, and in no way is trivial.

I wish I had an animated picture of this image because it took me a while to figure out how they did it...

>>3075089
>I wish I had an animated picture of this image because it took me a while to figure out how they did it...

SNES ToP as a whole is "how the fuck did they do it".

>>3075139
The music is especially advanced in ToP.

The streaming audio is really nifty. I don't know exactly how they did it, but the solution complicated by the fact there is no interrupt mechanism between the main CPU and audio coprocessor. I think they used timers in the APU and took advantage of V-blank happening at 60Hz to time a window to implement a very tight protocol.

Moreover the game featured fading between two tracks (think Valencia near musicians). Not completely impossible to figure out how they did it, but an extremely cool effect not seen anywhere else to my knowledge.

Btw, the ToP overworld is one of the best, if not the best looking mode 7 map on the SNES.

>>3075164
>Btw, the ToP overworld is one of the best, if not the best looking mode 7 map on the SNES.

I'd give that honor to Terranigma's underworld map or the one in Treasure Hunter G.
How was the split between the ground and the sky done in the first one, anyway?
In the same way as the splitting lava for Axelay's lava golem boss?

>>3075181
Terranigma's underworld is exceptionally well done. Actually the split is no more complicated than any other HDMA enabled effect. The creativity was in what to set the registers to every scan line. The effect is aided by the dark overlay obscuring the transition from the "inner sun" to the shell.

Haven't seen Treasure Hunter G's world map.

the entirety of recca
holy shit that game is nuts for the famicom

also this shit in crisis force, holy shit it looks good in motion.

>>3075181 >>3075216

I've always wondered whether they implemented that -after- they came up with the concept of setting that part in the "inside".

I can imagine some tech guys messing around with the tools and showing this CAF stuff that turned out by accident to the designers, who go "Holy Shit" and they actually write it into the game.

>>3075181 >>3075216

I've always wondered whether they implemented that -after- they came up with the concept of setting that part in the "inside".

I can imagine some tech guys messing around with the tools and showing this CAF stuff that turned out by accident to the designers, who go "Holy Shit" and they actually write it into the game.

>>3075181
Agreed

>>3075576
i think it looks like complete shit and is only there because they could

>>3075089
Neat; thanks for the explanation OP. Do ignore the anons that believe that being aware there's something to know counts as actually knowing it.

Pic is a quick gif made from a yt video. Sorry about the quality

>>3075586
That's entirely true of you as well

>>3075039
>>3075089
>>3075139

The tilting vertical shaft in the introduction is one of those effects I always thought it looked great, but I somehow took for granted until I actually tried to reproduce it recently for a little tile-based game I was doing

I only have a functional, hobbyist-level grasp of the code side of things, but as I understanding the whole map sort of rotates, but Samus and the actual gameplay axes remain straight, so it's not just buffering that shit and rotating it on display. Rotating platforming environments is trivial now with physic-based game... physics, but this was SNES, and therefore the maps were based on tiles

I ended up doing a quick-and-dirty slanting of the drawing operations (until just before displaying the HUD), but countered it for the character and their vertical movement axes by "rotating" them in the equivalent but opposite direction. With this, the characters show up where they should, but the environment seems to be rotating. My characters don't shoot that much, so there's no intensive bullet trajectories to correct.

So, savvy anons, how is this done properly?

>>3075629
>it's not just buffering that shit and rotating it on display
The SNES can't do that anyway. No buffer.

no idea about properly, but I'd leave the character and its motions, as well as any bullets, unchanged and upright. I'd disconnect collision detection from the tile map, using maybe some simplified lookups. No idea how precise the collisions are in that game section though.

>>3075629
The level tile map is mode rotated, the BTS is static but moved around accordingly.
The shaft never tilts over ±22.5 degrees so the illusion is pretty strong.
This video might help a bit: https://youtu.be/a8l13wMmi3w

The ceres section

>>3075669
BTS? Good video, by the way, quite helpful

>>3075672
BTS, or "Behind-The-Scenes." Essentially the physical attributes of a block. The green overlays in pic related.

>>3075751
never heard it called that, but seems to be a thing for that particular tool

Anyone have that Crash Bandicoot commentary where two developers were talking about all the insane backwards shit they pulled to get the game functioning?

>>3075762
The recent DevsPlay video was pretty lame, but there's a multi-part very comprehensive article around (google making Crash Bandicoot or whatever)

People feel it's mandatory doing this kind of stuff as a video now; I think it's nicer this way

I know this "trick" has been done to death and it's probably relatively simple but I always wondered how the background water effects were done in the old Sonic games.

>>3075039
The terrible thing about this was in the few rooms where using the scope would immediately cause an entire layer to just temporarily vanish

The whole fucking game :

https://youtu.be/FZKsQ09qOk4

>>3075998
Scrolling offset and palette switch at HBlank.

>>3076049
Sega systems had no HBlank

>>3076053
Surely there is an equivalent?

>>3076059
they couldn't, Nintendo had a patent on the HBlank

>>3076071
What are you talking about? Any system that drives a CRT has HBlank. The VDP even tells you when it's in it :

http://wiki.megadrive.org/index.php?title=VDP_Ports

You might be confusing it with the SNES particular implementation of HDMA, altough I'm not really familiar with the subject.

>>3075998
you took a sine and applied it to the horizontal offset of the scroll value of the background, then went through the sine step by step on each row. You changed the sine value after a frame so it is animated, then repeat.

>>3076071
>>3076053
Nintendo had no such patent. It would be absurd anyway, since hardware used it before Nintendo had them (Commodore had it for sure, not sure about the 2600).

Anyway it's not Hblank but h-interrupt, or more commonly known as raster interrupt: the display controller sends an interrupt to the cpu whenever it reached a specific line on the screen.

>>3076087
>Any system that drives a CRT has HBlank
Any Nintendo system, maybe.

>wiki
anybody can edit those

>>3076093
1/10

>>3076095
2/10

>>3076097
3/10

>>3076093
>anybody can edit those
You do know that wikis log all edits by default and show differences, right?

>>3076104
4/10

>>3076093
>Any Nintendo system, maybe.

HBlank is just the time it takes for the electron beam to traverse from the end of one line to the beginning of the next line. Nintendo would've had to patent CRTs themselves, which would've meant going up against the entire TV industry. They do not have a patent on HBlank.

What you might mean is raster interrupt, ie. setting up a hardware interrupt in the video controller, that signals the cpu with an interrupt, whenever the signal reaches a specified line.

But as far as I know they did not patent that, possibly because systems ALREADY had that. C64 has it for sure, Atari 2600 did almost every advanced effect that way (but I'm not sure if it had hardware interrupt or if the coders just measured everything tightly), and by the mid-80s every decent looking arcade system had some raster interrupt based special effects - either to wave the background around, or to display Outrun-like pseudo-3d ground.

tl;dr, you are full of it. Show us the exact Nintendo patent or fuck off.

>>3076125
>systems ALREADY had that
prior art only counts if it's contested in court

>by the mid-80s every decent looking arcade system had some raster interrupt based special effects
ever wondered why arcade games were so expensive? They had to pay Nintendo to use the HBlank patent

>Show us the exact Nintendo patent
it expired

>>3076136
Why do you keep doing that

>>3076137
>>3076053 was spot on in their description, and I felt like a little chuckle. Sadly, >>3076104 stopped responding. Would have been cool to get to 10/10, followed by a VBlank, even though 10 lines is a bit of a small display.

>>3075089
what game is this

>>3076139
>>3076137
fuck, wrong quote. Meant to say >>3076049 was correct

>>3076120
5 /10

>>3076136
>it expired
So it's been erased from history?

>>3076136
>it expired

You should still be able to find it online. Post a link or shut up.

>ever wondered why arcade games were so expensive? They had to pay Nintendo to use the HBlank patent

No, they cost so much because they used a large amount of very expensive chips, and a ton of mask roms as well.

>>3076170
What's a mask ROM? I know what bit masking is, but why a whole ROM for it?

>>3075629
OP here. This took a while to appreciate how it was done when I puzzled over it years ago. The implementation is actually very simple.

Clearly the background is using SNES Mode 7. In a nutshell, Mode 7 let's you transform a single background layer with 2x2 matrix and translate it with a 2D vector (math speek: a 2D affine transformation). The cool thing is that Samus moves with the background, and you can tell she interacts with the slanting floor as you'd expect. So how was this done, especially on old hardware?

Easy: You run the game physics like normal, with no modification. When it comes time to render the frame, you enable special programming for this room that tweaks the background and on-scene objects' RENDERED position using a single affine transformation; Mode 7 is used as usual, while Samus' has her normal render position transformed in software and then drawn to hardware. Where in the room to position the camera is more involved than usual, however under restrictions (like being a vertical shaft) the programming probably isn't that complicated.

>>3076146
4/10

>>3076267
>>3067292
Hey it's you again!

I don't know if there was anything particularly astonishing with Zero Tolerance on a technical level, but for being a 16-bit corridor shooter, it's hideously ambitious and detailed.

So I guess it's less if a "how did they do that", and more like "I can't believe they actually did that considering the game and the system it's on"

>>3075164
when it comes to the audio in ToP you can probably thank Yuzo Koshiro for that.
> Koshiro developed a sample loading system that worked with the ROM cartridge memory, swapping samples from the ROM data on the fly. This allowed him to "load parts of the music gradually as needed, and also change it quickly between stages or parts of a stage" which the "original system couldn't do it with its restrictions. A similar system was used by other companies for later SNES games such as Squaresoft's Seiken Densetsu 3 (1995) and Namco Tales Studio's Tales of Phantasia (1995).[17]

>>3076210
>What's a mask ROM? I know what bit masking is, but why a whole ROM for it?

https://en.wikipedia.org/wiki/Mask_ROM

Mask ROM (MROM) is a type of read-only memory (ROM) whose contents are programmed by the integrated circuit manufacturer (rather than by the user). The terminology "mask" comes from integrated circuit fabrication, where regions of the chip are masked off during the process of photolithography.

>>3077640

>>3077721
Jesus that's beautiful

>>3077741
is it? That's point light shadows, from what's definitely area light sources. It looks kind of forced. Technically pretty, but aesthetically a dud.

>>3077765
I dunno, I think it's technically impressive AND very pretty. Eye candy obviously but when you're deciding on how to present the intro, you can go the Super Mario World way and slap the static logo on the center of the screen or go balls deep with tinkering around the code. In my opinion this works well.

>>3075039
Ah, this reminds of Alone In The Dark: A New Nightmare, which has 2D pre-rendered backgrounds but the characters have lights you can use.
I thought that was a really nice touch since backgrounds you generally wouldn't interact with in those games; just 3D models that stand out looking obvious in the decor.

Anyway Tales of Phantasia looks like a fun game. SNES version better then?

IIIRC the game constantly loaded both backgrounds on screen, the lit and the non-lit one, so they can be switched at will. Reason why that game had atrociously long loading times during every camera angle change.

>>3077770
>you can go the Super Mario World way and slap the static logo on the center of the screen or go balls deep with tinkering around the code
false dichotomy and only covering the technical aspect, which was not under dispute

>>3077721
Thanks, love!

>>3077765
I think it's very pretty to look at.
Anyway, I remember the first time I played, I was on a rooftop, and suddenly I see something on a rooftop in the skybox, hey, someone's there, BANG!
It's an enemy sniper, and he's a part of the skybox, I'm supposed to crawl alongside a low wall to dodge his gunfire!
I was instantly struck by how they implemented a thing like that in a primitive corridor shooter in such a clever way!

Also the AI seemed to adapt it's behavior on the fly, based on how well you were doing, if you were sucking, they'd retreat or delay their actions, if you're kicking ass they'll act fast and start to crowd you.

Like, you can be cornered and doing badly, and the AI is throwing softballs, but if you turn the fight around and begin dropping mofos left and right like a smooth operator, the enemies will immediately do their A-game and stop pulling punches, it was so curious and interesting!

The game also supported multiplayer with two connected consoles, which I'm wondering how that works.

>>3077834
>I think it's very pretty to look at.
For point light sources it looks pretty. The huge letters behind him aren't point light sources and the disconnect is jarring

>the AI seemed to adapt it's behavior on the fly, based on how well you were doing
That's how it should be. Difficulty selections are bullshit.

>I'm wondering how that works
They transmit data between each other through the cable they're connected with

>>3077838
>For point light sources it looks pretty. The huge letters behind him aren't point light sources and the disconnect is jarring
What do you want, convolution using the letter shapes as kernels?

>>3078258
soft shadows, narrow letters, or a different sequence, that does not rely on the shadows being wrong
You do know these shadows are not realtime computed, right? It's just playing back an animation. So you might as well swap out the animation with something more fitting.

>>3078267
>You do know these shadows are not realtime computed, right? It's just playing back an animation. So you might as well swap out the animation with something more fitting.
Yeah obviously, but its the same sequence for every letter, presumably to save space.

>>3078275
almost, it's keeping at least different sequences for single shadows and multiple shadows
If space is an issue though, maybe the sequence just shouldn't be in there

>>3078285
You realise that the vast majority of people won't analyse it anywhere near the extent that we are, right?

Most people see it and go "wow that looks cool".

>>3078292
that's up to them. I just casually looked at it (never seen the sequence before) and went "woah, these shadows look wrong". It didn't work for me, at all. If it works for others, I can't judge. I'm just saying, it wasn't so much an analysis for me, as it was an instant gut feeling. The wording might have been analysis-y, but that's all.

>>3078305
I think you're over-not-analysing it, personally.

But I looked at it to see if the shadows were congruent with the letters, too.

>>3078308
>over-not-analysing it
explain

>>3078314
I wanted to say overanalysing but apparently you're not analysing it, so...

>>3078318
ah, just being a smart ass. Thought you had actually something worthwhile to contribute, my bad.

>>3078338
Almost. I was taking the piss out of you for being ultra-autistic, then your subtle implication that you weren't being anal at all. Apparently it was just that you're so super intelligent that you analyse everything in-depth without even trying.

Until that point, I thought I contributed admirably to the discussion. I just disagreed with you and that's what stuck in your craw.

>>3078360
>Until that point, I thought I contributed admirably to the discussion
Agreed, until that point. Then you had to piss it away with that dumb remark.

>I just disagreed with you
You were being an asshole about it. You ARE an asshole about it. So, with the utmost respect: Go fuck yourself and die in a fire, shithead.

>>3075039
In the second level of MDK most of the floor and walls seem to be mirrors that reflect the sky, however, it would have taken alot of processing power to pull that off, so what they did was simply render a skybox underneath the level and made the floor transparent.

>>3078369
Wow, all this butthurt over the playful insertion of a three letter word. Are you this fragile in real life? Because, if you are, I have news for you: this is the tip of the iceberg of what you'll face out there, among real people.

SUNSOFT bass. 'nuff said.

https://www.youtube.com/watch?v=LEgoYUzwabI

First 3D game to actually draw a z-axis instead of using optical illusions to fake 3D.

>>3078258
>What do you want, convolution using the letter shapes as kernels?
You speak my language. I like you.

>>3078338
All of these posts aren't contributing at all. The thread is about neat tricks on old hardware and how it was done. I don't see examples of tricks in games, nor how they were done, besides the initial post in this reply chain.

Anyway, the title screen effect posted by >>3077721 is cool because frankly I can't think off the top of my head a similar effect in any other game. Technically the rays of light are probably just a palette rotation on static graphics, but the idea and execution are unique, non-trivial (try it yourself and see how well you do), and memorable.

Btw guys, if anyone posts any demo scene stuff, that shit's about as insane as you can get.

To contribute with something else that has stumped me, in SD3, how the hell did they draw the overlays for the spell Rainbow? The ring consists of a high number n-gon (n~20) whos vertexes seem to be transformed and drawn in real time. It just seems like they'd be pushing close to the limit of what could be calculated in a single frame. Granted SD3 pauses gameplay when a spell is firing off, freeing up a substantial amount of cycles for special effects, but either the programmers wrote some slick code, or they just saved a shit ton of data to ROM.

Similarly, Super Metroid's power bomb has an expanding ellipsoid effect. If you watch it in slow mo, you can see the ellipsoid is drawn at different "granularities". I still wonder what they did to draw it, cause it seems like they didn't just draw an ellipsoid, but also had some scaling going on too, which means the ellipse was probably saved to ROM.

>>3078406
come again?

>>3078406
Outrun is 100% faked 3D:

http://www.extentofthejam.com/pseudo/

Toy Story's fake 3D.

>>3078420
>fake
yeah, no

>>3078420

One level has more layers than what should be possible on a SNES. There's also a 3D level that runs at 60fps and a Mario Kart-style level with smooth scrolling. All without a coprocessor.

>>3078420
Toy Story dominated the last thread, and while it's definitely chocked full of interesting stuff, much of it comes down to saving a shit ton of precomputed stuff to ROM. These games came out late in the consoles lifetime, and larger cartridges were the norm. For instance, I bet the leg windows were completely loaded from ROM.

Then again, I still never figured out how they pulled off the side view of the desks and bedstands in the room stages.

>>3078410
>Super Metroid's power bomb
iirc it's the same trick SMW's keyhole thing

>>3078429
>it comes down to saving a shit ton of precomputed stuff to ROM
welcome to the world of optimization
precomputation is trading space for processing power. you need less power, but more space.

>>3078416
>quoting a blog
You sure showed him wrong, champ.

>>3078420
Ok, now that I think about it, I think (the SNES is in Mode 1 and) the side view of the vending machines here is done on a separate layer (BG3) than the ground/background (BG1) and vending machines/tables (BG2). HDMA+scroll register updates are used to scroll the sideview and ground in a psuedo-3D manner.

The feet are just graphics loaded from ROM, no scaling/shearing is done by software.

>>3078427
The SNES is is Mode 0 here (4x 4-bit BG layers). The 5th background layer (prolly the yellow wires) is just done with objects (sprites). It's interesting that they did went with 5 layers, but the background is so busy that it fails to make an impact.

The propellers are loaded from ROM like the shoes, one frame at a time. It is interesting to note that the two propellers are at different phases. That means that both propellers have graphics memory allocated for them that is independent from the other. These guys are probably dynamically loaded and unloaded from VRAM when you get close to them. For an individual propeller, only one blade must be in memory at a time, for the second blade is just an HV-mirrored copy of the first.

That they implemented a 3D ray caster level is impressive, ala Wolfenstein, I will say. Haven't seen the Mario Kart level, but something tells me it isn't as busy as the Kart, so no coprocessor needed (which was mainly for vector math anyway)

>>3078440
Ah, the ol' temporal-spatial trade off. I find smaller ROMs more impressive, desu.

>>3078416
No, it has real 3D.

>The position and size of any billboard is generated by a (complete 3D) perspective transformation as are the vertices of the poly-line representing the center of the street. Often the center of the street is stored as a spline and sampled in a way that on straight streets every sampling point corresponds to one scan-line on the screen. Hills and curves lead to multiple points on one line and one has to be chosen. Or one line is without any point and has to be interpolated lineary from the adjacent lines. Very memory intensive billboards are used in Out Run to draw corn-fields and water waves which are wider than the screen even at the largest viewing distance and also in Test Drive to draw trees and cliffs.

>>3078485
>billboard
It's not real 3D.

>>3078505
Don't tell me you think only polygons can be true 3D.

>>3078505
retard confirmed