pros & cons... 16 bit cd games.

[Black Tiger]

I posted this before over at sega16.com, looks like dynamic tiles but not sure.

I believe that the warping is real time and nothing too special. If it's not just doing some sort of warping calculation on the fly (like other game chugging effects), I'm guessing that the tiles are just being line scrolled horizontally pixel by pixel SFII floor style while the bg pushes strips vertically.

The shading is the most impressive part for me. Tom said that it was similar to the shaded horizon in Chris Covell's Axelay demo. I believe that it's using the PCE's third layer which is something like a single solid color that can pierce through the bg layer, only for something like this it's being constantly updated...  or something.

[awack]

The shading is the most impressive part for me. Tom said that it was similar to the shaded horizon in Chris Covell's Axelay demo. I believe that it's using the PCE's third layer which is something like a single solid color that can pierce through the bg layer, only for something like this it's being constantly updated...  or something.

Yep, the stationary bans of color is what I'm talking about, i just checked out the Axelay demo and it appears to be the same effect.

[Tom]

I posted this before over at sega16.com, looks like dynamic tiles but not sure.

I believe that the warping is real time and nothing too special. If it's not just doing some sort of warping calculation on the fly (like other game chugging effects), I'm guessing that the tiles are just being line scrolled horizontally pixel by pixel SFII floor style while the bg pushes strips vertically.

The shading is the most impressive part for me. Tom said that it was similar to the shaded horizon in Chris Covell's Axelay demo. I believe that it's using the PCE's third layer which is something like a single solid color that can pierce through the bg layer, only for something like this it's being constantly updated...  or something.

 Yup. It's doing a full screen linescroll system for the warping. And you are correct about the PCE's BG color 0 layer. It's changing color 0 value on the same scanline interrupt routine. So as to keep a "fixed" image while the rest of the barrel rolls. Amiga does this quite a bit. The port of Bonk to Amiga by Factor 5 added a scroll layer by doing this. Many other Amiga games also do this.

 So no dynamic tiles there. A good example of realtime dynamic overlaid tiles is Ninja Spirit second level. The game code manually overlays the tree branches onto the dynamic tiles and uploads. It's one reason why slowdown occurs more in that level. While I'm sure the code isn't really optimized, IREM isn't exactly known of fast code, it is cool that they went out of their way to do some of these effects on early hucards  - when other companies were happy with minimal effort.

Edit:

When Dracula is hit, the scrolling BG will reverse and move backwards for a moment, i always thought the scrolling would stop and the reason was because the CPU was taking a hit(hit detection) but not sure about that now.

 I just took a look at that stage. The whole thing is done with H-int's (line scrolls). It takes the same amount of cpu resource to do the reverse movement than it does for the forward movement. And even when it's paused for a frame or so before the reverse movement, it still takes cpu resource to keep the frame as is (something like 100 fixed point ADDs isn't a resource hog. The bottom flipped half of the screen is just H-INT drawing the same BG but in reverse or upside down. I.e. you don't need another 100+ ADDs for the bottom half.). So I'd say it's done for effect. If anything, if it was a cpu resource issue - then it would result in slowdown and not a halt.

[awack]

I'm an idiot, i was wondering why you two were talking about line scrolling so i read where i said dynamic tiles dynamic tile got stuck in my head after reading Toms earlier comment about Rondo's shadow effect, anyway, what i wasn't sure of earlier was if the metamor jupitor color effect was the same as the rondo/magical chase shadow effect.

So I'd say it's done for effect. If anything, if it was a cpu resource issue - then it would result in slowdown and not a halt.

Thanks Tom, have always wondered about that because that fight is very impressive to me and thought the CPU had to be taking a hit before i  looked closely at it today running on an emulator.


It appears that you can plop the the BG layer over top of a big sprite(the moon) and not worry about hitting any limits that cause flicker.

[Tom]

I'm an idiot, i was wondering why you two were talking about line scrolling so i read where i said dynamic tiles dynamic tile got stuck in my head after reading Toms earlier comment about Rondo's shadow effect, anyway, what i wasn't sure of earlier was if the metamor jupitor color effect was the same as the rondo/magical chase shadow effect.

So I'd say it's done for effect. If anything, if it was a cpu resource issue - then it would result in slowdown and not a halt.

Thanks Tom, have always wondered about that because that fight is very impressive to me and thought the CPU had to be taking a hit before i  looked closely at it today running on an emulator.


It appears that you can plop the the BG layer over top of a big sprite(the moon) and not worry about hitting any limits that cause flicker.

 Hey! Haha, the moon is still behind the BG layer.  Nice find The sprite that flickers all depends on the sprite priority itself in relation to the other sprites. The lowest priority sprites are dropped first. It's possible the moon is low priority in the SAT (sprite table) and since it's behind the BG layer, you don't notice it flickering/blanking out - while the rest of the sprites show fine. Again, nice find

 Since we're on the topic of design stuff, Gate of Thunder has a part where a sprite is static/not moving and appears as part of the BG layer. But it fact it's not. I don't think it's supposed to be there. It's on the second level right before the boss fight. The other sprites using the same graphic as moving in that part like some sort of brackets or whatever. The only reason I noticed the fixed sprite was because it flickered. Thought that was really weird. Like something they missed since it blends in so well.

[Tatsujin]

indeed that's a nice find. but still i wonder, why they didn't outblank it completely?

[Tom]

Lords of Thunder desert level.







 The desert sand appears to be line scrolls, but they are not. Not in true fashion. They are dynamic tiles. There are only like 6-8 of them vertically and they repeat the tile horizontally via the tilemap. You update any single tile of pattern and the rest of the tiles horizontally are updated automatically - because the tilemap is pointing to that single tile for a lot of entries. The way LOT is using it, you get a scroll "layer" every 8 pixel. Now, the upper buildings and mountains are using the linescroll method, or more precise H-int's (Horizontal interrupts), just not on every line. Their data would be too much to implement on a dynamic system. They have not complex overlapping parts, so it's simpler to use a H-int method.

 Now, the large sand creature is also made up of mostly BG tiles. You can see in the third pic the "sprite" parts of the creature.

 If you look at the last pic, I edited the palettes of the dynamic tiles (and upper planes too) so you can see just the tiles of the creature. If the creature was made up of all sprites, there would be some considerable flicker. And since you can't use H-int's and have the creature as BG tiles on the same lines, they used dynamic tiles. The tiles around the creature are updated to give the scroll effect. But... the tile edges of the creature, the outside parts that contain 'sand' graphics, are not updated. So if you look really closely while the game is in action, you can see this. The fact that the colors are kinda gradient and only scroll every 8 pixels tall (the scroll height), makes it really easy to get away with this.

 If the dynamic patten was more pronounced, they could have made dynamic tiles for the outside edges of the creature as well. But in this case there's no need to.

 Lords of Thunder uses lots of dynamic tiles through out the game. The first part/area of the water level uses them too.



 The water parallax is done with dynamic tiles, same as the sand. This more easily allows overlapping parts like in the circled area in the pic, without using sprites.

[Black Tiger]

Lords of Thunder uses lots of dynamic tiles through out the game. The first part/area of the water level uses them too.



 The water parallax is done with dynamic tiles, same as the sand. This more easily allows overlapping parts like in the circled area in the pic, without using sprites.

That also allows the water to scroll right up to the vertically separation when you enter the cave. It's amazing how much many Super CD games crammed into a single section, when dynamic tiles were used.

[Tatsujin]

so amazing. not just your discovers (they're as well) but also the work and effort those programmers put into this, to get such beatiful things out of the pce. just imagine if they said "bahh no need, too lazy for that, no budget etc." a flat GoT or WoT really wouldn't be the same. and the most ashamed thing would be, that it would loose against the MCD version with a landslide.

[awack]

If the creature was made up of all sprites, there would be some considerable flicker.

I had always assumed that the dragon was a sprite.



I forgot about the transparent effects in the screens below.





A lot of people don't about this but Rondo gives you another  information display behind the vertical post.





After you enter the room with the spinning painting, shapes that flicker will appear.

That also allows the water to scroll right up to the vertically separation when you enter the cave. It's amazing how much many Super CD games crammed into a single section, when dynamic tiles were used.

and the most ashamed thing would be, that it would loose against the MCD version with a landslide.

I might need to do a detailed comparison of the sega cd and pce Winds of Thunder.

[Black Tiger]

a flat GoT or WoT really wouldn't be the same. and the most ashamed thing would be, that it would loose against the MCD version with a landslide.

If WoT/LoT had been completely flat, the Sega version wouldn't have all the layering it does. A few sections might've been split so that a single layer overlays at times. Parts in the actual release with simple 'Air Zonk' style parallax would remain flat static in a Sega port, because if they wouldn't have bothered/been capable to do it for the PCE version then they wouldn't have done it for Sega/Mega-CD since it requires no built-in features.

I've heard Sega fans trashing the LoT port as being sloppy sometimes say that it would've run better if it wasn't doing the layering the same way. But if it didn't do it the same way, the sections with added scrolling wouldn't have all layering that it does. I also suspect that in many places, like the desert "dragon", the Sega version likely does use a bg layer instead of dynamic tiles. Either way I think that they did an amazing job with the Sega version. The only unfortunate part is the new music, but just like with the color/detail, it's a matter of 'less good'.

[esteban]

TANGENT: Hey fabulous people... are any of you curious about an analysis of Jagu, the last boss in Legendary Axe?

I'm sure he is mostly comprised of background tiles, but he jumps around and stuff, so I'm curious. IIRC, his fingers and eyes are animated, so they're probably sprites.

Anyhow, I love all the stuff you are documenting in this thread. Good stuff.

[Necromancer]

TANGENT: Hey fabulous people... are any of you curious about an analysis of Jagu, the last boss in Legendary Axe?

I'm less 'fabulous' and more 'asshat', but count me in anyway.  I'm not really a L.A. fan either, but Jagu's pretty cool looking and I'd like to see how he works.

Anyhow, I love all the stuff you are documenting in this thread. Good stuff.

Indeed.  Thanks for the interesting read gentlemen; keep up the great work.

[Tom]

A lot of people don't about this but Rondo gives you another  information display behind the vertical post.

 That sprite post reuses part of the score display, that's why you see it like that. But it serves a different purpose:



 The post sprite is higher priority than the player sprite. So, the player sprite will appear underneath it. But... that column sprite is set to be behind the BG layer while the player sprite is set to be above the BG layer. When the player sprite crosses behind the column sprite, it's not shown because the column sprite is in the way - but the column sprite can't be seen so the BG tiles in its place are shown instead. This complex clipping using sprites. So the column sprite you can't see serves a specific purpose.

 

 Also, the outlined areas are dynamic tiles to simulate a second BG layer.




 The top part with Richter uses two tricks. The first is an H-int call on a specific line (that water line) and it changes every color in the sprite to solid blue. Since it's drawing out the screen, only the part of Richter from there, down, shows as solid blue. The other part is on that water line, it cycles turning all sprites on and off at 60hz. This makes the sprites translucent over the BG layer, but looks like the water is translucent.

 The creature/boss is just hard coded animation. The PCE having a ton of sub-palettes can afford it (i.e. not having to worry about sharing out subpalettes).

[awack]

The post sprite is higher priority than the player sprite. So, the player sprite will appear underneath it. But... that column sprite is set to be behind the BG layer while the player sprite is set to be above the BG layer. When the player sprite crosses behind the column sprite, it's not shown because the column sprite is in the way - but the column sprite can't be seen so the BG tiles in its place are shown instead. This complex clipping using sprites. So the column sprite you can't see serves a specific purpose.

That sounds like it would be difficult to program, i haven't seen any thing like it in any other pce game...yet.

I'm sure he is mostly comprised of background tiles, but he jumps around and stuff, so I'm curious. IIRC, his fingers and eyes are animated, so they're probably sprites.

If i had to guess i would say he is made up of sprites, if no one else knows, i will check it out.

I will mention that the first boss in Legendary Axe II is all sprites and almost as big as the last boss in Axe I.