Tearing Apart the SEGA Genesis OVERDRIVE MegaDemo by TITAN - Coding Secrets
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- čas přidán 23. 02. 2021
- Explaining how I think Titan produced the amazing effects in the OverDrive mega demo they produced for the SEGA Genesis back in 2013.
Videos referenced:
Puggsy Rotation Demo - • Puggsy 4th Prototype -...
Fire Effect (1995) - • SEGA Genesis MEGADEMO ...
Fire Effect (2018) - • Wanna Set Sonic on Fir...
Is That You or Are You You by Chris Zabriskie is licensed under a Creative Commons Attribution license (creativecommons.org/licenses/...)
Source: chriszabriskie.com/reappear/
Artist: chriszabriskie.com/ - Hry
I'm sure I got plenty wrong - and I'm sure you'll let me know here... :)
Yeah. Since it’s a full megademo
Well my right ear is a little lonely.
Please talk about the cancelled Swat Cats Mega Drive game.
Idk so much if its wrong persay but see a recent comment I made about the reflections at 14:00. I think they are using a single graphic for the sphere with a carefully calculated pallet such that changing the pallet can make it appears like there is a reflected color at the bottom, especially if you change the pallet only halfway down or through a render line.
I don’t understand a lot of this,, but it’s amazing to me.... I would love to see you make a shump just loaded with killer effects that only a master like you could pull off... Love the video’s buddy
Original dev here!
8:50 This is 2-cell V-Scroll and we worite 16 VScroll entries per line to do this. It's been a while but IIRC it's not interrupt based for timing reasons (interrupts are slow and fire quite late :( )
21:14 Most of this is correct, but we had to do a LOT of HScroll trickery as well to align the silver twister to 8 pixel boundaries, in order to do the layer priorities correctly (so that parts of it are behind the blue one and other parts are in front of it).
Thanks for the "review" :3 see you in the next one soon, hopefully? :D
Also, feel free to hit us up if you want to do a collab vid to explain some parts of OD1/OD2 in greater detail!
@@Oerg866 @codingsecrets I hope you're reading this!! Great idea Oerg866! Thanks for commenting, Big fan of your work! Can't wait for part 2 and what you have to say about it@UCkY047vYjF92-8HcoVTXAOg
@@Oerg866 Would be epic to see you and Jon team up and explain OD2.
Another original dev here ;)
8:50 correct, we just wait for a certain horizontal raster beam position to start transferring data
21:14 right, also all layers cast shadows onto one another
Regarding OD2, I‘d be happy about some kind of collab too - I wouldn‘t even know where to start explaining all those tricks
Omg, a collab would be amazing!
When you have one of the best Mega Drive/Genesis programmers have to second guess how something is done. Just makes you appreciate this demo and the people behind it even more.
More of a testament to the versatility of the hardware, with a deep knowledge of the hardware you can solve lots of problems in many ways. An intriguing video of a era never to be repeated.
I contributed to this thing and only now I'm noticing the shading on the spheres wtf?
The horizontal twister (6:47) is vscroll per 16px column mode with VSRAM being rewritten every line, so an extended variant of the effect right before it. The big catch is that there isn't enough video bandwidth to make it work, so display is disabled during hblank to pull it off (same trick as Mickey Mania, same trade-offs about sprites). This also becomes relevant for a bunch of other effects later.
The vertical double twister (20:05) is pretty much picking the appropriate lines, yeah. It may be worth noting that the priority flag has to be set carefully in order to allow the gray bars to be both in front and behind the blue bar as they spin (for those not aware, priority can be set on a per tile basis).
The really esoteric stuff comes in the second half of the demo (and Regen will *not* help make it obvious), so it looks like I'll need to comment more for that video… Also I have absolutely no idea how you'll deal with Overdrive 2 if you ever get to it since Regen can't emulate it properly at all (BlastEm can do it mostly fine and has some VDP debugger windows, but for whatever reason it doesn't have a proper pause button and you need to enter the GDB-like debugger for now, and the thing it exploits isn't even remotely obvious even with those debugger windows anyway)
Oh, and if certain effect in the latter half of the demo looks familiar… uh, yeah, we borrowed the idea straight from Puggsy lol
Overdrive 2 was amazing
Oh right, I only added those precalculated sphere reflections for the final version, the original version released at Evoke didn't have those.
Also, the horizontal twister does indeed disable display during the border (and adds a few sprites at the left edge of the screen to cover up artifacts caused by that that - as usual - only happen on real hardware, not in emulators) - in theory there should be enough bandwidth even without that trick but for some reason all I got was glitches so I went for the disable display trick instead...
@@kabuto3907 I think were all still wondering if it was just a pallette swap or different graphics too?
@@alexatkin There are 128 spheres without and with logo reflection each. Top and bottom half use distinct sphere graphics. The only real palette swap is for fading the reflected lightning bolt. Those 128 spheres were picked from 1024 raytraced spheres by discarding sphere graphics that turned out to be too similar.
Most of the technical tricks here are standard demo fare. What impressed me more than anything with all these demos is how amazingly creative the people making them are at designing the graphics to make those old tricks look so good. The pixel art is just gorgeous too.
Enjoyed this breakdown. Please continue with the rest of the effects in here. Then, try Titan 2 which is even more amazing, but sadly PAL only.
Well, your own fault for calling it "Genesis", your Megadrives have inferiority complexes! They need counseling, to realize their true potential. (I know it is a bandwidth and timing issue LOL :P), also: Does it run on emulators yet?
@@DehnusNorder Blastem should run it, I think. And yes, PAL Megadrives have enough bandwidth for 25 FPS FMV playback with only a slight screen size reduction.
Titan 2 definitly needs ntsc rom. Also 😆 at 🇬🇧 sonic like a slug omg
Titan 2?
Oh yeah what's the deal with the sega retro page claiming that PAL Mega Drives have higher DMA engine bandwidth than NTSC ones?
covering demoscene stuff is a REALLY cool idea, would be very interested in seeing more of this
You know, after having watched all of your videos a few dozen times at this point, I don't feel so lost now when you go into technical details. I even started to pick out some things before you mentioned them.
I-I think I've been... LEARNING... ON THE INTERNET!?! That can't be right, but thank you.
Yeah at this point it is starting to feel like the internet is more about getting distracted than learning like it used to be, so it is starting to become surprising. Actually I think it is more social interaction that is the problem. The time waster of the internet is the comments section. Without thoe it would pretty much all be learning.
this demo is super nostalgic for me. i know thats like, really zoomer of me but when i was 13 (when overdrive first dropped) i found this demo along with second reality and a few c64/atari800 demos through youtube recommendations/emulation sites. it sent me down a huuuuge rabbit hole and i hyperfixated on the demoscene for that entire year. this weird demo journey also made me fall deeply in love with demoscene culture and its had a huge influence on my music and art. maybe when the pandemic is over i'll scrape up enough cash to attend a demoparty... but i digress
titan fellas, wherever you all are, thank you so much for making this masterpiece
I probably only first saw this demo in like 2016 or 2017 I think. Never been sucked down any demoscene rabbit hole but like to watch a few for different systems. Recently I have found it hard to be sucked down rabbit holes due to distraction and having things I need to do, and worring about having not done things in the past 24/7.
Nice intro to the demoscene! I'd been into demos for years on and off, then I saw Second Reality running in Toronto at a computer store. My entire tax refund and most of my income for that year didn't go to food, it went into a 386/DX so I could run that demo.
You really make it sound like everything is possible on the Genesis. I'd love to see a video on how to make music for the Genesis today.
From having watched a lot of Coding Secrets videos, my go-to answer for so many effects now is "horizontal/vertical interrupts."
This was great. I've never seen any one dissect a demo like this before. Please, please, please do more!
Yes!!!! His videos are amazing
It is amazing. I love how he is really underwhelmed by the demo lol. he just understands what's happening but it's still funny
@@BubblegumCrash332 he used to make demos back in the day too!
@@BubblegumCrash332 It gets better in the second half, which he hasn't posted yet.
20:30 Yeah, twister bars have been done on all sorts of 8-bit machines as well, including the Atari 2600 and ZX81.
Excellent video, btw! Would love to see the next part.
Oh this is great, would you also do overdrive 2 as I thought they did such a great job of it
Let him finish this first, and then let his mind tumble for part two. I have no idea they pull this in 2 with this lack of cpu power, while playing also cool music, and samples !
@@realdonjoe yeah that's what's blowing my mind. Not the effects alone, but the calculations, the music, the transitions.
@@realdonjoe mega drive has a separate cpu that can handle sound/music.
@@jc_dogen shure, but not for for sample playback... and other things they do.
@@realdonjoe yeah... it can handle sample playback, and the overdrive demos use it for that. if you doubt it, it's been confirmed by the devs, and also not unusual at all.
I recall checking this demo out years ago and I thought it was so cool! But it's funny how it's all relatively simple effects. I think the real showcase of this demo is all the impressive maths to make these simple effects look spectacular.
Pretty sure the spinning "No Nintendo Inside" is column scrolling combined with hblank
Literally like Hollywood special effects expert breaking down a films effects hah love it
This is my new favorite CZcams channel. You've really opened my eyes to how particular effects can be achieved on hardware that maybe wasn't really designed for such stuff. I'm irrationally in love with the 3DO and my new goal is to learn how to program for it and maybe create my own thing that thinks outside the box. I really wish the 3DO had ingenious developers like yourself working on it and showing what the hardware can do.
Yeah it would be interesting to see stuff happen with the 3DO. Shame they are so expensive.
Please continue analyzing demos and their effects! There's endless amount of material for you to explore.
I really enjoyed this video. I'm not a coder but you explain things in a way that even I can understand. Would love you to do a part two. Keep up the good work!
I’d be interested in watching this sort of video on pretty much any demo made for any platform in the past 40 years. Great stuff!
Hooray so delighted to see more new vids here, can't wait for the second part. Easily one of my fav channels. Always amazed at what you could accomplish with some clever bits of coding.
I'd love to see more, thanks for doing this. On the twister at the end, just to simplify the explanation, there is 1 twist in memory and u select which line to show as the screen is scanned, skipping lines to squash and duplicating to straighten. After watching your mickey maina moose chase vid i realised u could have a striped twist and texture map it too!
Dude, I had one of your videos on my Watch Later playlist and I got around to watching it today and I can’t believe I was missing out on your amazing videos! I am now in the process of binge watching all the videos I missed due to not being subscribed to you until now!
Loved how future Jon corrected video Jon in the captions lol!. A delight to see, those 24 minutes flew fast!
It'd be interesting if you could comment on which of these effects could actually leave enough resources to have some gameplay going on like the one you used for Puggsy and which ones can only really exist in the realm of demos
THIS WAS WORTH *ALL* THE WAIT. I love these explanation videos and it helps me out with finding out the best ways to do things in my own projects.
Enjoyed it a lot. Enjoyed all of your videos a lot, so far ! Really cool to get an insight, how all those effects worked. Can't wait to see more. Please never stop with this content! Its just awesome.
I love this man's work
He didn’t work on this.
@@MrBLARG85 I know, but his games I do love
This is super interesting and I would love to see you explain the rest of the demo!
Looking forward to Part 2, and the second Titan demo. That one is even more impressive. Also, have you seen MegaColor videos running on a Genesis?
I'd love to see more on this demo, it's quite fun to see how this system works.
I love watching your vids. Please, please, please do more of these. Hell I’d watch anything you made on showing how they made any and all graphics on any game. Absolutely fascinating.
Really cool idea to dissect that demo! I didn’t understand a bit of it but love listening to your thoughts on my favourite console! looking forward to the next part 😁
I always appreciate your insight, so yes please do continue the demo breakdown!
One of the best videos yet! Definitely looking forward to a part 2 :)
That was brilliant, both the demo and the dissection. I can hardly wait for part 2 now!
This remains my favourite demo, and I applaud you for dissecting it. Hope you continue looking into it.
I LOVE THE BREAKDOWN. I'D BE HAPPY TO SEE MORE LIKE THIS.
Love demo dives and looking forward to more. Thanks for posting.
Shame Regen doesn't have a map viewer, that'd help for showing more of what they're working with.
This was my first demo breakdown. Thanks for the tour. It's a lovely machine.
That was cool! Thanks for sharing your critique and analysis, and welcome back!
Absolutely love your technical breakdowns. Fascinating stuff :-)
Looking forward to seeing part 2! I've been waiting for an explanation since the Demo came out!
Be sure to cover the Audio part as well
Just loved, please, do a part 2!
I am so happy your videos are back. Absolutely love your content, please keep it up!
Nice breakdown. Is love to see a part two and more of the same in general. Breaking down demo effects is a cool video series concept.
Thank you so much for doing this video, I think I may of even asked you to pull apart a Team Titan demo a year ago, but I could be just imagining it. Still, fantastic stuff, they are my favorite demo scene creators. Can't wait until you pull apart their second big Mega Drive demo masterpiece 'Overdrive 2',,, hint, hint, nudge, nudge. Thank you so much, I look forward to your second part to this particular demo scene video. Cheers - Australia
Really interesting. It's fun to watch you investigate other people's work and figure out how they did things. It shows your passion for coding and now I understand how much the people who made my childhood magical and fun really cared about making the best effects possible on the technology available at the time. It was a great era to be gaming and they still look fantastic.
I like your videos. They are always interesting. Looking forward for part two!
You should definitely do colab with the Devs. I think maybe digital foundry would be interested as well. If you can get those guys involved your channel will explode.
love it! excited to see the next video. its a long rom fx demo so you might end up doing more then two videos
Wow, fascinating look into how they do all these effects! Incredible sight to behold for Genesis software.
Part 2 here we come!!!! Great work squire
Awesome video! I like the demo scene tricks as well as the tricks used in games. If you start doing demos, too, you'll have quite a bit more material from which to make videos. Demos seem to be always packed with tricks.
I have wanted a video like this since discovering the Titan demo! Thank you for doing this coding secrets! So interesting! I can't wait for part 2!!!!!!
Coding Secrets, At 14:00 I suspect what they are doing, judging from the Pallet, is they have 1 single image, the lower part where the Reflection occurs is using cleaver color pallet such that it appears black... UNLESS it is using the pallet of whatever is in the center of the screen. This means all you have to do is change the pallet halfway down the screen... Or halfway through the line, to simulate reflection on the sphere of the object on the screen. Whatever the Object on the screens Pallet is made out of for those special reflection colors is what appears in the reflection. You can see what looks like evidence of it in the Pallet of the Memory.
I wish I could see what the pallet looks like Line by line as they render to be 100% sure but I suspect that is what they are doing.
Ah yeah that makes sense
That's the first thing I thought too, let's hope he sees this and replies
@@YOEL_44 We can hope, I left a response on his Pinned comment mentioning it so crossing my fingers. Only he can really confirm it since he has the software handy to check to see if the idea holds weight but over all I think it seems solid watching the pallet appear to kick around at special places as the center images swapped and what not. Doing stuff like that was a pretty common trick of the time to do animations of flowing things like water and stuff using pallet rotation so surely the idea would have been fresh in the dev teams minds as they attempting to come up with a means of simulating reflections.
Awesome, I didn't expect you would do that! Thanks!
This is a great idea for a new series on this channel, altough this video was not as edited as the others the analysis is good and the future visit of demos can only get better
I remember testing this rom with my emulator, Genefusto, and it failed miserably. Great video as always, want to see more !
I've always wanted to know how this amazing demo worked, amazing vid
Defo want to see a dissection of Overdrive 2, as well as cover how they got the audio to sound the way it does
this is amazing. i definitely want part 2!
This is brilliant, would be cool to see this breakdown of old mega drive games as well
Loved it. Amazing to see a Mega Drive pulling that off. Fascinated by the deconstruction. Loved it. Can't wait for part 2
Looking forward to part 2! This is all great stuff!
Always a treat when CS drops another video!!
great video! can't wait for part 2! Thanks!
Good introduction to a hardware platform I knew very little about. Cheers!
You think you'll do Overdrive 2 after this? That one honestly blows me out of the water.
Spectacular!! You must do more such vids :D
Yes! I'm glad, you're analyzing this demo!
I love you!
I'm a dev but too young to have worked on this stuff, so it's super interesting to learn about all this.
just awesome 😆 great explaination of the amazing sega genesis coding possibilities 👍
Loved the video, thanks for the upload
This is *exactly* what this channel should be. Perfect. 10/10. Thank you, this video is amazing!
Very insightful, keep em coming 👍
If these videos are too time consuming and you can't finish... Overdrive *2* Please!! And the music!! (Drooling continues!)
Absolutely love this. If you have the time can you explain registers and "fuses" think there is lot of confusion surrounding this and i think your the guy that can offer clarity on them, you have such a great way of breaking down complicated subjects and making them digestable for the o'l lamen like me :)
This is some wicked learning. Thank you.
Would love to see more like this. I love it!
Have you thought about doing a homebrew Genisis game and do like code devlogs? Think that would be fun to follow
Can't wait for part 2, and for even more tech demo teardown!
This is great, love it! Subbed.
Fantastic vid! A couple of things that weren't explained or I didn't understand that well:
- On the 3D bobs with sparks section, what determined how the spark/logo reflection appears on the bobs based on their Y position? How were the variations of each bob achieved graphically?
- On the twister section, how was the checkerboard shadow achieved?
Looking forward to part 2!
Love this peek into a demo!
It would be interesting to see Overdrive 2 analyzed like this also.
Thak you and it was a fun watch.
Lots can be done with few tools, if they are the right tools. Now to run off and find that demo.
really cool to get the opinion on an industry veteran, really cool break down, keep 'em coming.!!
Best video I've seen on the new channel!
Great video as always !!
You should take a look at Overdrive 2 next.
Probably one of the most impressive Sega MegaDrive tech demos I've seen. It requires using an emulator like BlastEm to even run similarly to running on actual hardware.
Very well done. I personally do the same with Amiga Stuff all the time. Just working on Leander and found the very impressive Map-Scroll of the Main Game. Never though of this way. Great Video !!!
Are you reading my mind? I just watched this a few days ago thinking "Man it'd be cool to see this thing in Coding Secrets"
Really awesome stuff!
Super cool stuff! I’m wondering what kind other impressive demos could be made in the modern era on other old game consoles too.
Jon rips the demo to bits! Good stuff!
I swear to god I'm going to lose my mind if and when Coding Secrets breaks down the second demo. Oerg, Sik, y'all better be there too. Hell, tell Strobe that it would dope if he chimed in on the wizardry he does with audio!
Love this channel thanks mate!
I'm fascinated by your videos! Thank you very much! Please do one explaining how they did all the effects in The Adventures of Batman & Robin for Sega Genesis.
More! Loved the format. Did I say - More!