Has anyone tried to get a "Mode 7"-style game working on the Amiga?

Tigerskunk · 06 March 2018, 14:21

Today I saw this and was heavilly impressed:

[ Show youtube player ]

and this

[ Show youtube player ]

And I wondered if this would be possible on an OCS Amiga..
I know the MD has chunky mode, which makes a lot of this 3D stuff faster..

But still...

Add: don't know, why there were two threads created when I clicked "post"... Sorry for that... :/

fryguy · 06 March 2018, 14:38

EDIT: Didn't notice the OCS part.

Both these are AGA only:

[ Show youtube player ]

[ Show youtube player ]

Galahad/FLT · 06 March 2018, 15:04

The first youtube video should be doable in some form. Its highly cheated or at least, the mode 7 engine on that game knows its limitations, which is why it has no very tight turns.

The Sonic one is pretty impressive.

Street Racer was pretty good for the A1200 and the graphics were far more detailed, i'm guessing a cut down version must be at least possible on OCS.

dlfrsilver · 06 March 2018, 15:12

Brian the Lion is the best example of a game using the Mode 7 from the snes

Tigerskunk · 06 March 2018, 15:31

I guess I should have specified that I especially meant those perspective floor tiles, not just rotozoom fx..

Amiga1992 · 06 March 2018, 15:36

There's this too:
[ Show youtube player ]
(in case link doesn't take you to the time, jump to 1h32m55s)

DamienD · 06 March 2018, 15:51

Quote:

Originally Posted by Steril707

Add: don't know, why there were two threads created when I clicked "post"... Sorry for that... :/

Other duplicate thread now removed

Tigerskunk · 06 March 2018, 15:54

Quote:

Originally Posted by DamienD

Other duplicate thread now removed

Thanks, Damien...

chb · 06 March 2018, 21:55

Just a note: Both the "Sonic Kart" and the F-Zero clone are by gasega68k/Stephane Dallongeville, which was also active here at eab as "Stef_" (account closed unfortunately).

The Mr. Nutz fly stage is not Mode7-like, as it's only zooming without rotation. Uses the scroll register trick to scale the lines.

But concerning the original question: I do not know of any examples, maybe there are some demo parts?

saimon69 · 06 March 2018, 23:16

I remember some copper chunky perspective demos in the past but those were having the zoom and not rotation; plus i seems to remember the limit of 8 pixels for the OCS/ECS copper; road might look pretty blocky but if we focus on playability that should be fine

malko · 06 March 2018, 23:51

Quote:

Originally Posted by chb

Just a note: Both the "Sonic Kart" and the F-Zero clone are by gasega68k/Stephane Dallongeville, which was also active here at eab as "Stef_" (account closed unfortunately).[...]

Maybe one Moderator

could look at the closed profile and try to send him an e-mail ??

Tigerskunk · 07 March 2018, 09:29

Would be amazing, if he could join in the discussion and explain a bit how he accomplished the outstanding work he did on the MD..

alexh · 07 March 2018, 10:41

Quote:

Originally Posted by Galahad/FLT

Street Racer was pretty good for the A1200 and the graphics were far more detailed, i'm guessing a cut down version must be at least possible on OCS.

Would that be considered a "Mode 7" game? The playfield is very narrow. You can never see any other parts of the track other than the bits you're driving on. It's more like OutRun than Mario Kart / F-Zero.

Amiga1992 · 07 March 2018, 16:18

Quote:

Originally Posted by alexh

It's more like OutRun than Mario Kart / F-Zero.

Yeah agreed, not mode7-type effects, it was mode7-like on the SNES, but not on the MD/Amiga

SNES/Sega:
[ Show youtube player ]

Sega/Amiga:
[ Show youtube player ]
(look at that, the AMiga version seems smoother)

DanScott · 07 March 2018, 17:27

You *could* do something like this on OCS Amiga

You could go for a copper screen 8x8,8x4,8x2 pixels.. or even a "fake" 4x4 (or 4x2) as used in some demos (see Unique - Multicolor demo for example)

[ Show youtube player ]

Another alternative is to use a HAM 4x4 (or 4x3, 4x2) using the 7 bitplane trick (that enabled HAM mode but only enables 4 DMA channels.. the Modify bitplanes are written directly to the Bitplane 5 & 6 data registers)

This was used in the following demo:

[ Show youtube player ]

With a game engine like this, you would not be able to use just a bitmap for a track or floor, as the resolution would be too small for anything expansive. Your rendering code (for each "pixel") would need to index a block, then to index a pixel in that block, so the overhead is somewhat more. You could precalculate quite a lot of lookup tables for this, but then memory usage would also be quite high

But the answer is yes, I think that this could be done on a500

Amiga1992 · 07 March 2018, 17:36

Those examples are rotozoomers, don't look at all to what Steril wants to do, really. He alredy mentioned "no rotozoomeers" on an above post.

malko · 07 March 2018, 17:54

Quote:

Originally Posted by malko

Maybe one Moderator

could look at the closed profile and try to send him an e-mail ??

By PM I have asked DamienD. Unfortunately he answered me that there is no e-mail available.
Sorry Steril707. Maybe an EAB member knows somebody who knows somebody that can contact him

(I know it's like trying to send an e-mail to a 20 years old address, but who knows... )

DanScott · 07 March 2018, 20:52

Quote:

Originally Posted by Akira

Those examples are rotozoomers, don't look at all to what Steril wants to do, really. He alredy mentioned "no rotozoomeers" on an above post.

1) As the A500 can't push pixels to the screen partcularly quickly, I was giving examples of screen modes that *could* be used to display a mode 7 style floor

2) If you ever investigated how a mode 7 style floor works, it is essentially the same as a rotozoomer, except that the x/y texel positions and dx/dy are calculated slightly differently. Other than that, the inner workings of the 2 should be practically identical.

chb · 07 March 2018, 22:29

Stephane is still active on the Sega16 forum, so should be easy to contact him there:

http://www.sega-16.com/forum/member....1357-gasega68k

I'd guess blitter-assisted c2p should be fast enough to do a 2x2 (or fake 1x2 like in britelite's wolf3d demo and seemingly gasega6k's demos) mode7 at half screen height at a reasonable frame rate, maybe using some self-modifying code for the texture mapper. But I do not see an obvious approach for the scaling in z - you'd need to generate code for every line because the scaling is different, in a rotzoomer it's fixed and you need only to generate code for a single line. Maybe a combination of c2p and scroll register trickery?

Tigerskunk · 08 March 2018, 09:00

@Dan Scott:
Super interesting idea, using Copper Chunky.
I guess first off, you'd need to calculate tiles into an intermediate buffer, and after that move everything into one of two copperlists.

06 March 2018, 14:21	#1
Tigerskunk Inviyya Dude! Join Date: Sep 2016 Location: Amiga Island Posts: 2,770	Has anyone tried to get a "Mode 7"-style game working on the Amiga? Today I saw this and was heavilly impressed: [ Show youtube player ] and this [ Show youtube player ] And I wondered if this would be possible on an OCS Amiga.. I know the MD has chunky mode, which makes a lot of this 3D stuff faster.. But still... Add: don't know, why there were two threads created when I clicked "post"... Sorry for that... :/

06 March 2018, 14:38	#2
fryguy Registered User Join Date: Aug 2005 Location: Skarabörg, Sweden Age: 44 Posts: 1,019	EDIT: Didn't notice the OCS part. Both these are AGA only: [ Show youtube player ] [ Show youtube player ] Last edited by fryguy; 06 March 2018 at 15:22.

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06 March 2018, 15:04	#3
Galahad/FLT Going nowhere Join Date: Oct 2001 Location: United Kingdom Age: 50 Posts: 8,986	The first youtube video should be doable in some form. Its highly cheated or at least, the mode 7 engine on that game knows its limitations, which is why it has no very tight turns. The Sonic one is pretty impressive. Street Racer was pretty good for the A1200 and the graphics were far more detailed, i'm guessing a cut down version must be at least possible on OCS.

06 March 2018, 15:12	#4
dlfrsilver CaptainM68K-SPS France Join Date: Dec 2004 Location: Melun nearby Paris/France Age: 46 Posts: 10,412	Brian the Lion is the best example of a game using the Mode 7 from the snes

06 March 2018, 15:31	#5
Tigerskunk Inviyya Dude! Join Date: Sep 2016 Location: Amiga Island Posts: 2,770	I guess I should have specified that I especially meant those perspective floor tiles, not just rotozoom fx..

06 March 2018, 15:36	#6
Amiga1992 Registered User Join Date: May 2001 Location: ? Posts: 19,645	There's this too: [ Show youtube player ] (in case link doesn't take you to the time, jump to 1h32m55s)

06 March 2018, 21:55	#9
chb Registered User Join Date: Dec 2014 Location: germany Posts: 439	Just a note: Both the "Sonic Kart" and the F-Zero clone are by gasega68k/Stephane Dallongeville, which was also active here at eab as "Stef_" (account closed unfortunately). The Mr. Nutz fly stage is not Mode7-like, as it's only zooming without rotation. Uses the scroll register trick to scale the lines. But concerning the original question: I do not know of any examples, maybe there are some demo parts?

06 March 2018, 23:16	#10
saimon69 J.M.D - Bedroom Musician Join Date: Apr 2014 Location: los angeles,ca Posts: 3,519	I remember some copper chunky perspective demos in the past but those were having the zoom and not rotation; plus i seems to remember the limit of 8 pixels for the OCS/ECS copper; road might look pretty blocky but if we focus on playability that should be fine

07 March 2018, 09:29	#12
Tigerskunk Inviyya Dude! Join Date: Sep 2016 Location: Amiga Island Posts: 2,770	Would be amazing, if he could join in the discussion and explain a bit how he accomplished the outstanding work he did on the MD..

07 March 2018, 17:27	#15
DanScott Lemon. / Core Design Join Date: Mar 2016 Location: Tier 5 Posts: 1,211	You could do something like this on OCS Amiga You could go for a copper screen 8x8,8x4,8x2 pixels.. or even a "fake" 4x4 (or 4x2) as used in some demos (see Unique - Multicolor demo for example) [ Show youtube player ] Another alternative is to use a HAM 4x4 (or 4x3, 4x2) using the 7 bitplane trick (that enabled HAM mode but only enables 4 DMA channels.. the Modify bitplanes are written directly to the Bitplane 5 & 6 data registers) This was used in the following demo: [ Show youtube player ] With a game engine like this, you would not be able to use just a bitmap for a track or floor, as the resolution would be too small for anything expansive. Your rendering code (for each "pixel") would need to index a block, then to index a pixel in that block, so the overhead is somewhat more. You could precalculate quite a lot of lookup tables for this, but then memory usage would also be quite high But the answer is yes, I think that this could be done on a500

07 March 2018, 17:36	#16
Amiga1992 Registered User Join Date: May 2001 Location: ? Posts: 19,645	Those examples are rotozoomers, don't look at all to what Steril wants to do, really. He alredy mentioned "no rotozoomeers" on an above post.

07 March 2018, 22:29	#19
chb Registered User Join Date: Dec 2014 Location: germany Posts: 439	Stephane is still active on the Sega16 forum, so should be easy to contact him there: http://www.sega-16.com/forum/member....1357-gasega68k I'd guess blitter-assisted c2p should be fast enough to do a 2x2 (or fake 1x2 like in britelite's wolf3d demo and seemingly gasega6k's demos) mode7 at half screen height at a reasonable frame rate, maybe using some self-modifying code for the texture mapper. But I do not see an obvious approach for the scaling in z - you'd need to generate code for every line because the scaling is different, in a rotzoomer it's fixed and you need only to generate code for a single line. Maybe a combination of c2p and scroll register trickery?

08 March 2018, 09:00	#20
Tigerskunk Inviyya Dude! Join Date: Sep 2016 Location: Amiga Island Posts: 2,770	@Dan Scott: Super interesting idea, using Copper Chunky. I guess first off, you'd need to calculate tiles into an intermediate buffer, and after that move everything into one of two copperlists.

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