Emulators Reveal Sega Saturn's 'Hacky' Transparency

The consoles of yesteryear, with their limited hardware resources, forced developers to pull all sorts of tricks to fake certain visuals. Take transparency (which to this day we still haven't mastered) — on the Sega Saturn, coders took advantage of the fuzzy nature of TV screens and analog signals to cheat this effect where they could.

It's a bit more complicated than that, as Matt Greer explains on his blog, but without the aid of emulators and high definition displays, the average (well, slightly savvy) Joe would have no idea that games, like Mega Man X4, did not always use transparent sprites for things like spotlights.

Look at this image for example, which shows the game on the Saturn (top) and PlayStation (bottom):

Can you see the difference? The Saturn used a "meshed" version of the sprite, which basically means only every other pixel is drawn, while the PS has true transparency. Not that this was a big deal back in the day, as this "dithering" ended up being blurred on our crappy TVs and cables:

When the Saturn was a current console, most people were hooking it up to their TV using composite cables. Composite is a low quality signal that combines all of the color information into a single blurry stream. This meant the mesh effect was not as noticeable, as the mesh pixels would tend to average out in the blurriness and result in a decent approximation of transparency. Complaints of the Saturn's meshes really started to rise when emulation and use of upscalers like the XRGB Mini enabled people to play Saturn games with a crystal clear picture.

It's hard to believe, but I'm sure 20 years from now we'll be pulling apart the likes of the latest Star Wars: Battlefront and all the dodgy stuff EA DICE had to do (maybe).

The Sega Saturn and Transparency [Matt Greer]

Images: Matt Greer


Comments

    Love this system with all my heart. Similar to this write-up, there are some great video's by YouTuber LowScoreBoy that delve deep into the when's, why's and how's of the Saturn's ability to draw tranparancies. It could indeed do it, but was limited in what else was on the screen at the same time, and which processors were doing it. I find it still such a fascinating system :)

    Last edited 30/01/16 9:46 pm

    Why haven't developers mastered transparency yet? What's the issue(s) holding them back?

      It isn't mastered yet?

        Take transparency (which to this day we still haven’t mastered)

        ^ Quote from the article.

      Its a non-issue now, because we can throw more processing resources at the problem and have more refined rendering engines, but back then there would have been limitations to what you can do with the hardware, and for something as large as that spotlight, having to render half of a space as yellow pixels uses less processing power than rendering the entire space as yellow pixels and calculating the required blend from underneath.

      Emulators replicate the game roms exactly as they were, so you'd have to recompile/rebuild the game to change in order to add in new features like transparency.

        Sorry I meant to reply to you but the article states we still haven't mastered it.

      This is probably heaps nerdy, and I've barely even scratched the surface. Worth noting that all of this is with the disclaimer that I tend to analyse things, but I don't know all the specifics of game rendering, so:

      Mostly computing power. There's a whole bunch of edge cases regarding transparency that are way too resource intensive to bother designing/coding around. An old issue (that's being increasingly fixed on this gen of consoles) that's fairly indicative of the issues is depth of field with alpha transparencies. This can crop up as a bunch of fairly obvious issues but it's clearest with hair in games. Basically, if you're in a cutscene, you've got someone's alpha hair, and there's a DoF you either ignore the transparent elements in your depth pass (so all the hair that isn't in front of something at the focal depth is blurred), you fully include them (so the hair is in focus, but so are the transparent elements of the mesh, which makes whatever's in the background of them in focus), or you add a pixel (texel, maybe?) check into your depth pass for alpha elements so that it knows the edges, and you may even need to add some form of extra sampling along the edge to help smooth it, all of which chews up more processing time.

      This doesn't even touch the issues of how you construct the image-to-be-blurred, which can add more issues, particularly in regards to alpha-transparencies.

      And this is one tiny element. Another (vaguely quick) example: For something like a window, handling all the transparencies there is fairly simple, but the way renderers are set up means that if you had a glass sculpture with lots of strange angles that crossed over itself many times you'd probably have issues where it overlaps itself, not to mention that you wouldn't be accurately simulating how the light moves through it, what caustics it would create, and so forth.

        I appreciate the in depth reply but I don't have the specific knowledge to understand most of it haha.

          Haha, yeah, sorry, geeks gonna geek, I might be able to explain it better with pictures, but I'm far too slack for that.

    No read the article again, he literally says we still haven't mastered it.

      I'm confused too, as article also states that the PlayStation had "true transparency".

      Transparency aside, Saturn has the best version of Symphony of the Night. I had hoped when it was rereleased on 360 a decade ago they would have merged the two versions together. Alas, just the PlayStation version got released. SotN was my journey to the dark side of playing games in Japanese. Now I enjoy the likes of EDF4 and Musou Orochi. Thank you SotN <3

        What made the Saturn version better?

        Still got to get around to playing that, pretty sure it's the only Igavania I haven't got. Stupid lack of Nintendo ports :P

          Basically new enemies and new areas to explore, here's a list:
          http://www.castlevaniacrypt.com/sotn/saturn

    Saturn version had extra area with another playable character. It also had frame rate issues not present in PSX version. Apparently.

    These posts remind me of that classic Simpsons episode where Homer just isn't picking up what the police are putting down:
    So Mr Thompson I'm going to stamp my foot...
    *whispers* " I think he's talking to you"

    Wasn't a similar trick used to make it out as if the Mega Drive was displaying more colours than it could? The developer would fill every second pixel with back or white to create a different tone or hue

    GUARDIAN HEROES!!!!
    my fav saturn game ever - right there next to saturn bomberman!

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