Metroid Prime hacking research

Edit history:

Antidote: 2015-05-21 08:53:16 pm

2015-05-21 08:52:41 pm

The code falls under a different law in and of itself. It's perfectly OK to reverse engineer and reimplement the engine, so long as we do it in a "clean room" i.e we don't use any of their original code, either in part or in whole. None of us are doing any such thing so we're perfectly ok.

Lord Fredrik

2015-05-21 09:02:31 pm

Thanks for clearing the "assets" part, guys. I was worried about my fan-game using Nintendo assets. But do fan-games fall under the same rules as commercial games?

jackoalan

2015-05-21 09:11:16 pm

Quote from Lord Fredrik:

Thanks for clearing the "assets" part, guys. I was worried about my fan-game using Nintendo assets. But do fan-games fall under the same rules as commercial games?

I'd be leery about redistributing Nintendo assets ad-verbatim.. I've seen plenty of fan games to the contrary, but that doesn't guarantee full legal protection for all cases. It would probably be wise to explore the concept of 'fair use' and ensure you don't run afoul.

Antidote

2015-05-21 09:13:39 pm

While Nintendo isn't known to attack Fan game projects I'd definitely be leery about using them verbatim as Jack says, use their style yes, assets? Be extremely careful.

jackoalan

Edit history:

jackoalan: 2015-05-21 09:46:41 pm

jackoalan: 2015-05-21 09:46:03 pm

jackoalan: 2015-05-21 09:43:41 pm

jackoalan: 2015-05-21 09:42:43 pm

jackoalan: 2015-05-21 09:41:58 pm

jackoalan: 2015-05-21 09:20:50 pm

jackoalan: 2015-05-21 09:19:16 pm

2015-05-21 09:16:21 pm

Also, here's a perfect example of a (legal) project that replaces a game's engine, but uses the original assets and scripts: http://scummvm.org/

Such a project requires end-users to supply their own game-disc as input, but allows for playing the game on different platforms.

EDIT:
Here's a (surprisingly relevant) case that illustrates the US Courts' views on game modding:
https://en.wikipedia.org/wiki/Lewis_Galoob_Toys%2C_Inc%2E_v%2E_Nintendo_of_America%2C_Inc%2E

Lord Fredrik

2015-05-21 09:30:57 pm

The assets in question are 3D models converted to sprites, and many songs converted to ogg formats.

Thanks, mates

Antidote

2015-05-21 09:40:17 pm

That might fall under "derivative works" in which case you're gold. Still be careful about it ;P

Lord Fredrik

2015-05-21 09:42:27 pm

Okay! Thanks a lot, guys, Appreciate it!

MrSinistar

2015-05-22 04:01:07 am

Jackoalan and Antidote helped me figure out the RoomAcoustics SCLY Object! Hearing EDH with cathedral-like reverb was pretty crazy, haha.

http://www.metroid2002.com/retromodding/wiki/User:MrSinistar/Sandbox#SCLY_RoomAcoustics

Aruki

2015-05-23 11:49:39 pm

There are a couple things I haven't figured out yet, but I've managed to get MP3's bloom rendering in PWE mostly correctly. I could probably try to do a writeup on the technical details on the wiki if anyone's interested.

Aruki

2015-05-24 01:05:35 am

A side effect of implementing bloom is that MP1 looks much much better now

jackoalan

2015-05-24 02:29:34 am

Aruki

2015-05-24 02:30:46 am

Oh, don't worry, I know exactly what the problem is. I was informed on Twitter that I needed a filter to make everything brown to make MP1 truly look like a modern game, so I went ahead and did it. Everything is fixed now.

jackoalan

2015-05-24 02:32:14 am

Bravo! GOTY material right here!!

Aruki

2015-05-24 02:32:54 am

Yeah. I mean it came out in 2002 but I think my changes are significant enough that we could consider it a whole new game.

Aruki

2015-05-25 02:25:13 am

With MP3 material support implemented, it was pretty trivial to add DKCR MREA/MLVL support. Got it loaded correctly within an hour or so of work. Unfortunately DKCR really really needs skyboxes and none of the MLVLs have default ones set...

Jesse

2015-05-25 06:03:17 am

The skyboxes are flat anyway.

Lord Fredrik

2015-05-25 12:02:14 pm

Whoa. Those Returns assets look great.

Aruki

Edit history:

Aruki: 2015-05-26 01:24:21 am

2015-05-25 10:46:56 pm

Random material stuff

* Compared to MP3's 12 PASS types, DKCR removed four of them - BLOL, BLOD, BLOI, and XRAY - and added two new ones, RIML and TOON. TOON is supported by the game but it's not used by any files. Have not looked into what they do yet but I probably will soon.

* DKCR still has both CLR types (CLR and DIFB), but only has one INT type (OPAC) to MP3's five. I'm not sure what the four removed ones do exactly, but from the names I would guess they're related to bloom/X-Ray, which would make it obvious why they would've been removed.

* I can't quite figure out what the issue with RFLD is that makes the Elysia skybox appear stupidly bright. It's related to flag 0x400; if you unset that flag, then the skybox appears stupidly bright ingame too. But I'm not having much luck determining specifically what that flag actually does.

* I can't really figure out what LRLD and LURD do because neither of them appeared to actually do anything in my shader dumps, nor do they seem to have much of an effect ingame. They're both present in DKCR, but LURD is unused. LRLD is used though and I guess they probably wouldn't have kept using it if it didn't do anything.

* The gist of MP3's bloom rendering is this: The game renders the main scene to a texture, with the bloom maps being rendered to the alpha channel of the framebuffer. The resulting texture is alpha-blended on black to produce the texture used for blurring. To "blur", the bloom texture is drawn at half brightness, then additively blended on top of itself six times with horizontal adjustments each time. There's multiplier colors applied to the passes further away from the center so they appear darker and don't bloom as brightly as the passes closer to the center. After that the image is lowered to 50% brightness again and the process is repeated with vertical adjustments. The result of this is additively blended on top of the original scene texture, then the HUD and other UI elements are drawn on top to complete the frame. I will probably write this up with pictures and more technical details soon - I feel like the MP3 materials page on the wiki needs a major cleanup so that would probably be a good time to do it.

If anyone's wondering about that MP1 picture, the reason that happened is because I implemented bloom the same way Retro did. The problem was since MP1 obviously doesn't have bloom maps, almost EVERYTHING rendered full white to the alpha channel, which meant almost EVERYTHING got the brightest bloom possible. I've fixed the issue since then.

* I'm not totally sure whether DKCR uses bloom or not since its materials don't have any of the bloom stuff that MP3 had. There are some effects ingame that look like bloom, but I haven't looked into it.

Random material stuff

* Compared to MP3's 12 PASS types, DKCR removed four of them - BLOL, BLOD, BLOI, and XRAY - and added two new ones, RIML and TOON. TOON is supported by the game but it's not used by any files. Have not looked into what they do yet but I probably will soon.

* DKCR still has both CLR types (CLR and DIFB), but only has one INT type (OPAC) to MP3's five. I'm not sure what the four removed ones do exactly, but from the names I would guess they're related to bloom/X-Ray, which would make it obvious why they would've been removed.

* I can't quite figure out what the issue with RFLD is that makes the Elysia skybox appear stupidly bright. It's related to flag 0x400; if you unset that flag, then the skybox appears stupidly bright ingame too. But I'm not having much luck determining specifically what that flag actually does.

* I can't really figure out what LRLD and LURD do because neither of them appeared to actually do anything in my shader dumps, nor do they seem to have much of an effect ingame. They're both present in DKCR, but LURD is unused. LRLD is used though and I guess they probably wouldn't have kept using it if it didn't do anything.

* The gist of MP3's bloom rendering is this: The game renders the main scene to a texture, with the bloom maps being rendered to the alpha channel of the framebuffer. The resulting texture is alpha-blended on black to produce the texture used for blurring. To "blur", the bloom texture is drawn at half brightness, then additively blended on top of itself six times with horizontal adjustments each time. There's multiplier colors applied to the passes further away from the center so they appear darker and don't bloom as brightly as the passes closer to the center. After that the image is lowered to 50% brightness again and the process is repeated with vertical adjustments. The result of this is additively blended on top of the original scene texture, then the HUD and other UI elements are drawn on top to complete the frame. I will probably write this up with pictures and more technical details soon - I feel like the MP3 materials page on the wiki needs a major cleanup so that would probably be a good time to do it.

If anyone's wondering about that MP1 picture, the reason that happened is because I implemented bloom the same way Retro did. The problem was since MP1 obviously doesn't have bloom maps, almost EVERYTHING rendered full white to the alpha channel, which meant almost EVERYTHING got the brightest bloom possible. I've fixed the issue since then.

* I'm not totally sure whether DKCR uses bloom or not since its materials don't have any of the bloom stuff that MP3 had. There are some effects ingame that look like bloom, but I haven't looked into it.

Baby Sheegoth

2015-05-25 10:52:23 pm

Can.... can you take some pictures without bloom in mp3? Id like to see how much prettier the game is.

Aruki

2015-05-25 10:53:41 pm

I linked a picture on the last page. http://i.imgur.com/SIoU0sJ.jpg

Baby Sheegoth

2015-05-25 10:56:01 pm

Quote from Parax:

I linked a picture on the last page. http://i.imgur.com/SIoU0sJ.jpg

I'm sad because that really does look so much better.

jackoalan

2015-05-25 11:02:29 pm

It's truly a shame that bloom was such a popular gimmick back then..

It ruins the contrast and detail of Retro's beautiful diffuse textures.

Aruki

2015-05-25 11:05:38 pm

I actually think the game overall looks worse without bloom... mainly because the baked lighting was clearly done with bloom in mind.

Example: Gel Processing Site without bloom | with bloom

There's some lights highlighting some statues along the wall, which adds a lot to the scene, but they're done on the bloom maps instead of on the lightmaps, so with the bloom removed there's no spot there and the scene looks duller overall. There's quite a lot of this sort of thing in various places in the game. The bloom maps also serve to brighten up the stage in a lot of areas so without the bloom they look a little bit too dark.

Of course if they had just baked this detail into the lightmap in the first place there wouldn't be an issue here, but...

Baby Sheegoth

2015-05-25 11:29:46 pm

See, this is why design is interesting. I personally think without bloom looks much nicer, because you can see the intricate detail on the textures of the statues.