Dissecting the console ports of Hexen

So I guess it's been a little while since I've done one of these, but as of late I've taken an interest in the console ports of Hexen. Hexen stands out as being the only other Doom engine game that was ported to multiple consoles back in the day. Each of the three ports have their own little quirks about them, so I guess I'll document what I've found out about each of them here:

Sony Playstation:

The Playstation port of Hexen is commonly regarded as the worst of the three console ports, which is surprising considering how well regarded the Playstation port of Doom is. So what exactly went wrong with this version? Here's some random info:

⦁ This version was ported by Probe Entertainment, who also made Alien Trilogy for the PSX and Saturn only a year before they ported Hexen.

⦁ One common rumor about this port and the Saturn port is that they were both based off of an unfinished beta of the PC version, which would be a possible reason for simplified levels, one sided enemies, and other strange quirks inherent to these two versions. This rumor is still unconfirmed though.

⦁ Of the two disc based ports, the PSX version appears to be the more primitive of the two as it runs at a slower framerate, has slower scripting, and lacks gibbing enemies. One would assume that the PSX version is the earlier of the two, but it actually isn't. Release dates on GameFAQs state that the Saturn port came out two months BEFORE the PSX port. On top of that, the dates attached to the files on the PSX disc all date from either January or March of 1997, whereas the files on the Saturn disc are mostly from the Fall of 1996.

⦁ Scripting only appears to be slowed down by how much content is being rendered by the screen. Much like Saturn Doom, opening the automap or turning to face a wall during script events makes them go at the same speed as the other ports. Otherwise, they are comically slow. The funniest instance are Korax's taunts at the beginning of each hub. The "frames" of his face appear and disappear on the wall like a slideshow instead of smooth animation, the time between different voice clips is about double to triple the amount of time in other ports, and after he speaks the door remains closed much longer than it normally should.

⦁ Files on the disc are arranged very similarly as to how PSX Doom's are. There are five folders, titled CLUSTER1, CLUSTER2, and so on which contain six more folders that have the data to each of the games levels. There appears to have been an error in numbering the levels though, as there are no Map numbers 14-20 (Also true on the Saturn disc). Also, the maps in folders CLUSTER3 and CLUSTER4 appear to have been swapped as they break the sequential order (CLUSTER3 having MAP27-34, CLUSTER4 having MAP21-26)

⦁ Within each map folder are seven files which make up each map. The actual map itself is stored in a WAD file. Each folder also has a .TEX file (for each map's textures?), a .SPR file (for sprites?), an .AVF file (which contains all the SFX for that map only), as well as a .SPN and .TC file, which I can't tell what their purpose is.

⦁ The WAD files can be opened individually in both Slade and Doombuilder (under the regular Doom and Doom II map types, but not under Hexen map types), but appear to be compressed in some unknown fashion. Opening them in ZDoom gives a invalid vertices error. Viewing the maps also show the maps as a thin straight line. Sidedefs also give the same texture names as their PC counterparts, although this port appears to refer to individual .TEX files for level textures instead of a master WAD file like PSX Doom. Most interesting however is that between the map's Blockmap and Behavior lumps is the familar Leafs lump as originally seen in PSX Doom. According to Doomwiki, the Leafs lump was created by Williams Entertainment for PSX Doom, so were Probe perhaps using PSX Doom as a reference for their port of Hexen?

⦁ Other file folders include a STR folder, for all the game's FMV cutscenes. A PLAYERS folder which contains, among other technical things, various IMG, BIN, and LMP files used for in game graphics, plus player sprites (which is odd since there is no multiplayer mode in this version, I'm guessing they are for the three final sub-bosses) plus an AVF file for all the sound effects that you hear in each level (weapon sounds, player and some monster noises, etc.). Also there is a SCREENS folder which features IMG files for the game's titlepic, end title sequence, credits, etc.

⦁ All the graphics in this version appear to be stretched horizontally, like when you stretch 4:3 content to fill a 16:9 screen. This applies to everything in the game; sprites, font, and even textures. The HUD is stretched to the point where you can only see the gargoyle's face at the very edge of the screen. Portals are also stretched to the point where you can't even see the silver border surrounding them. A good comparison of this phenomena can be seen in this video.

⦁ Saving and loading in this port is atrocious. Hexen is actually one of the few PSX games which requires all 15 blocks (120kb) of a memory card for just one save. The process of both saving and loading takes at least 30 sec. both ways, but usually takes longer. Also, this is the only way you can save your game. If you don't have a completely empty memory card on hand, then tough luck as no alternatives are offered.

⦁ Monsters seem to have more strength in this version. For example, Ettins that normally take three punches as the fighter to kill in the PC version take about 6 or 7 to kill in the PSX version.

⦁ Most levels feature a new colored "animated" sky that appears to be exclusive to this version. It appears to consist of two graphic "layers", one stationary layer and the other being animated (scrolling from right to left).

⦁ Chaos Serpents are all brown in this version, unlike all other versions which have also have a green colored variation.

⦁ Sound effects are pitchshifted at random in this port, much like earlier versions of DOS Doom.

⦁ Non-game related, but the instruction manual is also an absolute mess. The monster listing is messed up, with one page's monster descriptions accidentally being printed twice next to different monsters (ex. Ettins have the description for Stalkers, Chaos Serpents have the description for Wendigos, which are already printed on the page before). The game credits (which are just copied from the PC version) are also printed twice as well... right next to each other on opposite pages.

Sega Saturn:

Most people tend to think that the Saturn port of Hexen was handled by the same group who ported it to the PSX, but this actually isn't true. Whereas Probe Entertainment appear to have "produced" this port, it was actually developed by the now extinct Swedish development company Atod. Atod appears to have used the same resources that Probe made for the PSX port (FMVs, music, map design), but made a port that was a lot more enjoyable to play:

⦁ The title screen and main menu actually have music in this port, which is strangely absent from the PSX version.

⦁ This port has an extremely extensive debugging menu. Some interesting features allow you to turn monsters on or off, kill all monsters in a level, run individual game scripts, and even allows for you to turn clipping off. Regular cheats such as level warps and god mode are also included, and you can also run a multiplayer game as well if you have a system link.

⦁ The music in this version is the same as the PSX port, with two additional CD audio tracks. The first track on the disc is the title music for the main menu, and the other being the track is Orb. Despite having the same soundtrack, the tracks are arranged in a different running order on the Saturn disc. Much like other Sega Saturn FPS games, tracks are assigned to levels in sequential order (Map01 has the second audio track, Map02 has the third audio track, and so on) meaning that certain songs play on different levels in this version compared to the PC and PSX versions (For example, this version plays the track for Darkmere (Swamp) on The Seven Portals).

⦁ There is no organization in the files on the disc. Everything is just arranged in alphabetical order and that's it. Maps are stored in two different files in this version, a LMP file and a .TRN file. The LMP is always larger in filesize of the two, and opening the TRN file as Raw Data in Audacity reveals all the SFX the level uses amongst other static. (As a side note, doing this with DOOMTONE from Saturn Doom reveals all the game's SFX played out in one long chain)

⦁ As another side note, 0.BIN, a file that is included on all Sega Saturn games, appears to be the actual "game program" which is loaded into the system memory, as inspecting this file in a hex editor reveals all the same hex and other text that showed up in a Sega Saturn emulator's memory editor.

⦁ Saving is still a pain in the ass in this version. In order to save your progress, you need to have an official Sega Backup Memory Cartridge. As a compromise, a password system was programmed in. However, it only updates once per hub, so you need to complete each hub in one sitting in order to get a new password.

⦁ The oddest thing that I've seen so far in this port is a strange 'moth' like creature which inhabits the exit room of Hub 2: Shadow Wood. This 'moth' is only a few pixels wide, is a silver like color and moves at a speed faster than any of the monsters move. When you turn on the map all things cheat, the 'moth' shows up as a thing on the map. It bounces around the room in a random pattern turning in direction randomly as it moves. This is the only port that this occurs in, and I will look into it more to see what exactly this "moth" really is. Thanks to Use3D for pointing this out to me.

Nintendo 64:

Commonly referred to as the best of the three, I'm sadly not able to get into as many of the complexities of the N64 port as I am with the other two disc based ports simply due to the fact that cartridges are a much different animal than discs. However, I've recently purchased the Japanese version of the N64 port, and this version has actually been censored to remove the game's more "gorier" elements. All blood has been recolored to a slime green color, and unlike the Japanese version of Doom 64 which only recolored the blood splatter sprites, this version has ALL sprites edited to change their blood color. On top of that, numerous decorative sprites throughout the game have also been edited. Sprites that feature bodies impaled on spikes and bodies hanging from the ceiling have been carefully edited to remove the gore. Here are a few comparison images, the censored Japanese version is on the left and the Uncensored North American version is on the right:









Some other things of interest:

⦁ The Japanese version has none of the original English characters, the majority of the text in the game is written in Japanese. Korax has also been redubbed to speak Japanese as well.

⦁ The localizers couldn't be bothered with translating the text that appears on loading screens between levels which gives a description of the level. Instead, this image is shown between levels along with the same colorful animation on the top and bottom of the screen:




⦁ Localizers also couldn't be bothered with translating the between hub intermission screen text either, so it has been left in English.

⦁ Save games that are created with one regional version of the game are completely compatible with the other region. Doom 64 functions the same way as well, so all of the changes made to the Japanese version appear to be cosmetic.

Mattfrie1 said:

⦁ Files on the disc are arranged very similarly as to how PSX Doom's are. There are five folders, titled CLUSTER1, CLUSTER2, and so on which contain six more folders that have the data to each of the games levels. There appears to have been an error in numbering the levels though, as there are no Map numbers 14-20 (Also true on the Saturn disc). Also, the maps in folders CLUSTER3 and CLUSTER4 appear to have been swapped as they break the sequential order (CLUSTER3 having MAP27-34, CLUSTER4 having MAP21-26)

Just a note on this, the wacky map numbering is true to the PC version as well, although there's a "warptrans" variable in the MAPINFO that re-numbers them for the purposes of the -warp parameter and VISIT cheat.

Nice find!

You should consider contributing to The Cutting Room Floor. They managed to beat you to the punch regarding the green blood and Korax's speech though...

HavoX said:

Nice find!

You should consider contributing to The Cutting Room Floor. They managed to beat you to the punch regarding the green blood though and Korax's speech though...

Their article was actually the reason why I hunted down a copy. Finding the censored decoration sprites was a bit of a surprise though.

I think the idea that the PSX/Saturn versions are based on the PC store beta is due to things like the enemies' higher health values in common, certain inventory items share the same images which are different from the retail PC version, IIRC using some of the puzzle items, etc.

Another interesting thing about the PSX Hexen is Korax actually has full rotation frames, unlike the Saturn version.

EDIT: Also, even though there apparently is a lot of level simplification in the PS1 and Saturn ports, there's also some oddities. Like the room past the emerald key door in level 1 is extended to the left in the ports, instead of a simple rectangle. There's also the switches around the outside of the perimeter in Castle of Grief that are more spaced out and even one that's considerably relocated. The latter is another element that is found in the PC store beta.

I have always been interested in the differences of the N64 port of Hexen.

buttspit said:

I think the idea that the PSX/Saturn versions are based on the PC store beta is due to things like the enemies' higher health values in common, certain inventory items share the same images which are different from the retail PC version, IIRC using some of the puzzle items, etc.

Another interesting thing about the PSX Hexen is Korax actually has full rotation frames, unlike the Saturn version.

EDIT: Also, even though there apparently is a lot of level simplification in the PS1 and Saturn ports, there's also some oddities. Like the room past the emerald key door in level 1 is extended to the left in the ports, instead of a simple rectangle. There's also the switches around the outside of the perimeter in Castle of Grief that are more spaced out and even one that's considerably relocated. The latter is another element that is found in the PC store beta.

The PSX version actually has a 59kb IMG file called KORAXTEX located in the PLAYERS folder which most likely contains those rotation sprites. No equivalent file exists on the Saturn version though, which explains the difference.

I've done some more digging around on both the PSX and Saturn ports. I've been looking around at some files from both discs in a hex editor and found some interesting info:

First off, Opening each PSX level's WAD in the editor reveals a text string at the beginning which makes mention of IWAD version: 2.3. As far as I know, there is no version 2.3 of any Doom engine IWAD, which makes this rather intriguing. Also, the PLAYERS folder has a 37kb LUMPINFO.DIR file which when opened in a hex editor looks very similar to how a WAD is formatted. The text appears to feature start and end markers at several points, marking off areas for powerup sprites, textures, and the rest of the games sprites. Sprites appear to be renamed though to have between 4 to 6 character names. At the end of the file is an end of wad marker as well.

Also mentioned a lot throughout the files of the disc are DEPTHOF4.BIN and DEPTHOF8.BIN files, for which I have no clue what their purpose is.

For the Saturn version, opening 0.BIN in a hex editor reveals a lot of interesting text. Towards the beginning of the file are text strings for the game's menu screens. There is a lot of text in here for the game's unused multiplayer modes, including what appears to be a link game option menu which allowed you to choose between deathmatch and coop, what map to play on and the option to turn monsters on and off. Towards the end of the file is a lot of "debugging" text and module names for the game's code (stuff such as RenderViewCone, MapHeight, RenderMap) and other stuff which looks like assembly instructions (addu, subu). Also, opening the MapXX.LMP files also features various texture names scattered throughout the file.

Are there any THING entries in the txt strings for these MapXX.LMP files? It would be neat to find what that damn moth is called.

Mattfrie1 said:

First off, Opening each PSX level's WAD in the editor reveals a text string at the beginning which makes mention of IWAD version: 2.3. As far as I know, there is no version 2.3 of any Doom engine IWAD, which makes this rather intriguing.

Nope, that's the same as PC Hexen. Open the Hexen IWAD with SLADE 3, click on a map header, and then click on "edit level header script". You'll see "version 2.3" on all of them.

So the N64 version has voice dubbing in French, German and Japanese, interesting.

Use3D said:

Are there any THING entries in the txt strings for these MapXX.LMP files? It would be neat to find what that damn moth is called.

Nope, sadly all I can find are texture names, some script names (EX. KoraxVoiceBlood,FireDemonAttack,MaulatorHamSwing) and sound names(Ambient1 ,Ambient2, etc.). There appears to be no master WAD file anywhere on the disc, so I'm assuming that all the data pertaining to the levels are contained in the .LMP and .TRN files and are compressed in some unknown fashion. I do have my own theory on what the moth could be, but I sadly can't investigate any further at the moment as my Saturn AV cable died and I'm waiting for another one to come in the mail.

Another interesting thing I have found on the Saturn version is with the file SND_DRV.BIN. Text at the beginning of the file states the following:

 ADPCM SFX driver for SEGA SATURN
Written by Virtually Unreal Ltd. for Probe Entertainment LTD. Copyright 1996.
Virtually Unreal LTD. Produced for use in Die Hard Trilogy and Alien Trilogy ONLY

I guess somebody didn't listen...

I intend on poking around my PSX and Saturn copies of both of those games on the off chance that there any other elements that might have been used between the three games.

Wait, the Japanese version is the censored one? I thought the Japanese video game market was much more tolerant to graphic violence.

JohnnyTheWolf said:

Wait, the Japanese version is the censored one? I thought the Japanese market was much more tolerant when it came to graphic violence.

You would think so but...

Really odd, indeed. I do not know if there are Japanese users on this forum, but I would be interested to hear their take on this. Even back in 1995, Japanese games did not seem to shy away from blood and gore, and Hexen does not strike me as particularly worse in that regard than, say, Castlevania.

JohnnyTheWolf said:

Really odd, indeed. I do not know if there are Japanese users on this forum

There are some (most of which probably participated in this thread), but I'm not sure how much interest they have in Hexen.

Cool. If you're curious, this says 異次元の扉 (gate to another dimension). If you're interested in translating more stuff from the game, I can probably help.

Mattfrie1 said:

Nope, sadly all I can find are texture names, some script names (EX. KoraxVoiceBlood,FireDemonAttack,MaulatorHamSwing) and sound names(Ambient1 ,Ambient2, etc.).

KoraxVoiceBlood, FireDemonAttack, MaulatorHamSwing etc. are sound names too. They're defined in SNDINFO in the PC version and it sounds like that might be what you're looking at in these too.

I had a feeling that those might be sound names, but I wasn't really sure. I guess I should have poked around the PC version a little bit more before really diving into the quirks of these console ports.

JohnnyTheWolf said:

Really odd, indeed. I do not know if there are Japanese users on this forum, but I would be interested to hear their take on this. Even back in 1995, Japanese games did not seem to shy away from blood and gore, and Hexen does not strike me as particularly worse in that regard than, say, Castlevania.

Several members who posted in my old Doom 64 in Japan thread had some interesting insights into gaming censorship in Japan. For a semi-recent example, I believe the only country that got a censored version of Duke Nukem Forever was Japan.

Memfis said:

Cool. If you're curious, this says 異次元の扉 (gate to another dimension). If you're interested in translating more stuff from the game, I can probably help.

Awesome, I've uploaded a 10 minute video of the game's attract sequence to YouTube which showcases a few of the Japanese version's differences overall:

I'm also going to make a video of the "moth" in the Saturn version as well when I get the chance, I will update this post accordingly.

So here it is finally, the mysterious moth of the Shadow Wood exit room:

Some things to note about the video:

-In the first segment I used the "carnage" cheat code to rid the map of monsters. By the time I get to the room, the "moth" is already activated.

-In the second segment, I start the map with monsters deactivated. The "moth" remains stationary in the middle of the room.

-In the last part, I go to the end of the room with monsters activated. The strange thing is how the moth appears to be dormant when I first approach the room. Once all the monsters have been killed in the room, the "moth" wakes up and moves around the room.

Honestly, I'm more surprised that the PC version doesn't have that. Seems like it'd be simple enough to implement that serves the same purpose as like the rats from Strife.

Why of all things to implement?

Maybe a bored porter just wanted to write something new for a change.

Since getting an official Sega Backup Cartridge, I've finally had time to sit down and really get into the Saturn version. Here's some random notes I've made on this port so far:

-Some sound effects appear to be missing in this version and are replaced by other sound effects. For example, the sound that normally plays when you pull a puzzle switch has been replaced by the teleportation sound effect. Also, the splash that plays when you step into water is also missing, and replaced by the ambient water drop sound effect.

-Looping sounds, such as sounds that play when a door is opening or a lift is moving are not in this port and thus these objects make no noise at all. This really threw me off in the Guardian of Ice as all ice "movements" (such as where the steel key is located) are completely silent, not alerting you to the change in level architecture.

-Hexen is known to Saturn enthusiasts as a memory hog. As stated before, the game only saves if you have an official Sega backup cartridge which aren't too easy to find nowadays. One Hexen save game takes up a wopping 3801 blocks on the backup cart, which has a little over 7000 blocks overall. The game allows you two save spots if your cart is completely empty.

-In a move of complete stupidity, the developers will only allow you one spot to save if it detects anything else on the memory cart. The stupid thing is if you have a game saved in the second save spot and you save another game's data on the backup cart, Hexen will "lock" you out of any game saved in that second save spot. It still exists on the memory cart, but there is no way to select it in game as only the first save spot is displayed. Oops.

-The .TRN files I mentioned earlier appear to be all the sound effects that are used for that level. Monster sounds, Korax's taunts, plus the missing sounds I mentioned earlier (ex. lifts in the Guardian of Steel, bubbling lava in the Guardian of Fire) are some sounds I can pick out. Importing the raw file into Audacity as ADPCM and setting sample rate to 11025 allows you to hear them, but they are very staticy.

-A file called GENP.FIX appears to have all the player sound effects, plus other sounds such as switches that are used in every level.

-As an aside, a similar sound effect system is used in the Saturn port of Die Hard Trilogy which was also made by Probe (.TRN files for each level, plus a general file for sound effects used everywhere ingame plus the sound driver I mentioned earlier).

-There appears to be no framerate cap on this port. Areas with very few monsters and not a lot of architecture (ex. beginning of Guardian of Ice) run very smoothly, almost in the 60 FPS range I would guess.

-Textures are better animated on the Saturn version than the PSX version. The best example would be the teleporter gate to travel between levels. The PSX version only has two alternating textures that go back and forth, whereas the Saturn version has the full animation just like the PC version.

I've also looked a little into the ROM of N64 Hexen, and found was able to find what looks like the IWAD. From what I can see, all sprites appear to have the same names as their PC counterparts. Levels also appear to formatted in the same way as the PC maps as all the lump names are the same for each map. For the Japanese version, the yellow FONTAY font set was removed and replaced in the IWAD by 4 sets of Japanese characters (JAPAN000-JAPAN096, JNUM0-JNUM9, JPUN0-JPUN2 and JKANA1-JKANA84). It is then followed by FONTA (small white font used in intermission screens) and FONTB (Red font found in menus of all other versions, but appears to go unused in this Japanese version of the game).

So thanks to doing some research into the beta version of Hexen that is floating around the web, I have finally found out the identity of the mysterious "moth". As it turns out, the "moth" is in the final beta version, and is actually supposed to be a fly. Four sprites for the fly exist in the WAD of the beta, all under the title of AFLY which come between the sprites for Korax and the pig. The thing type ingame is 112 according to this website. There is even a sound for the fly called FLY2 that is defined in SNDINFO and also included in the WAD of the beta as well. Curiously, the only remnant of this fly in the retail WAD is the info given in SNDINFO, as well as the sound for the fly which is titled FLY3 and is longer in duration. I even poked around the files for the Hexen source code to see if any code was left in for the fly's behavior, but I couldn't find any.

Someone else has uploaded a video of the fly in the PC Beta version to see for yourselves:

I've also done some more poking around with the PSX port and found some interesting info at the end of a file called SLUS_003.48 (which is the games catalog number BTW). Every PSX game features a file named after their catalog number which is what I'm guessing is loaded into the system's RAM on system startup. At the end of the file is a list of sprites, AFLY is listed here so I'm guessing the fly is in this port too. Also of interest are marker lumps. I count a total of four sets of markers, M_START and M_END, T_START and T_END, F_START and F_END, and S_START and S_END.

Curiously, there actually appears to be several minor differences between levels in the PSX and Saturn versions. In Map 01, the Saturn version as two sets of bars going vertically down the four windows of the Bell Tower blocking the player from running out of them, whereas the PSX version has no bars on the windows at all. Also, in Map 02 when the entrance to Bright Crucible opens the PSX version only has two of the stone "pillars" open. The Saturn version has all of the "pillars" open however.

Thanks for all your research!

A mysterious individual known only as "Shambler" has written up an article at the doom wiki to cover the fly https://doomwiki.org/wiki/Fly

There's plenty of other work to be done on the wiki to document the beta version(s) :)

Is that you, Glacie?

Also, does this mean the Saturn version is a port of the beta? I wonder what the idea behind the fly was, just something you would see occasionally in various areas? I wonder why they left it out since they had it complete. Strange and interesting!

Doomkid said:

Also, does this mean the Saturn version is a port of the beta? I wonder what the idea behind the fly was, just something you would see occasionally in various areas? I wonder why they left it out since they had it complete. Strange and interesting!

It's possible, and same with the PS1 version. In fact, after seeing a youtube vid of the Saturn port, I noticed Ettins dying after 3 punches from the Gauntlets. In PS1 port, like the PC store beta, enemies seem to have around twice as much health (or weapons do half damage); so maybe this one's more of a straight port of the beta.

The one thing that really interests me at this point is the inclusion of the LEAFS lump in the maps of the PSX port. In playing through the PSX port, I have noticed some graphical similarities between both PSX Doom and PSX Hexen. Perhaps someone with a bit more knowledge on how PSX Doom works can shed some light on the topic. Here's some similarities I've noticed:

- In sectors that have either a moving ceiling or floor, textures on the walls appear to distort while the ceiling/floor is moving. The distortion is that the textures appears to slightly "crawl" up and down. This is most noticeable on lifts that are placed right up against a wall.

- When in an outdoor sector, indoor sectors that have a taller ceiling height sometimes render the ceiling flat as "floating" in midair. I'm pretty sure this exists in PSX Doom, but I definitely know I saw it several times throughout Saturn Doom.

- Textures appear to tile horizontally if you view them from an extreme side angle. A good example of this is to look at any switch texture from an extreme side angle.

Keep in mind also that I have not seen ANY of these same graphical anomalies in the Saturn port of Hexen, which raises a few questions in itself.

I put together a video very similar to one that Kaiser posted in my Saturn Doom thread showing how PSX Doom is rendered by the system. Here you can see that PSX Hexen renders in a very similar way...

EDIT: Looking closer, it also appears that the frames are rendered "non-stretched" in VRAM.

Here's Quasar's video of how PSX Doom renders for comparison:



I also viewed the Saturn port in the same debugger that I used earlier this year for Saturn Doom, and not surprisingly Saturn Hexen uses the dual video processors much more efficiently than Doom did. For the record VDP1 was used to render sprites, textures and polygons, and VDP2 was used to render backgrounds. In Saturn Hexen, VDP1 is used to render all sprites that are on screen during that particular frame. Monsters and scenery show up as scaled sprites and HUD elements are mostly normal sprites. There also appears to be a few polygons being rendered by VDP1 as well. Most curiously, weapon sprites appear to be split up into several "distorted" sprites instead of being rendered as just one sprite. VDP2 handles rendering the actual level itself as one background layer. Turning VDP1 off in the emulator gives a very similar experience to 32X Doom when the cord connecting the 32X to the Genesis isn't plugged in. The level itself is present, but all the sprites are missing.

Take a look at who I found buzzing around Shadow Wood on the PSX port:

As I figured, the fly exists in the PSX port too, it's just that it is much harder to find. The behavior of the fly seems to differ in the PSX version as well. Instead of just bobbing up and down aimlessly like in the Saturn version, in the PSX version it actually almost seems to be going from corpse to corpse investigating. It even stops at one point right in front of my face as well. The most interesting part is at the end, when the fly either gets stuck or lands on a pillar in the exit room. It slowly ascends all the way up to the ceiling, where it stops and stays there permanently.

Another small difference between Saturn and PSX ports. The PSX version actually has rotation sprites for a few in-game objects. Several others already mentioned Korax earlier, but smaller objects such as the darts and ice shards that come out of wall traps also have rotation sprites in the PSX port. What is also interesting about this is that the several objects with multiple rotations exist in special .IMG files in the PLAYERS folder away from the rest of the game's resources. By contrast, the Saturn port only has front facing sprites for all of these things. This means that things such as darts and ice shards only have front facing sprites, and appear to be flying sideways and backwards in the Saturn version much like the rockets in 32X Doom.

OK, time for some theorizing. From what I've seen, there's no doubt in my mind now that both the PSX and Saturn ports are based off of a beta version. Why Probe decided to use a beta version instead of the actual finished retail is beyond me though. Perhaps they thought the beta version would better work with the smaller RAM size of the two consoles?

The PSX version obviously uses the same modified Doom engine as the PC version. Many Doom engine quirks (random sound pitches, corpses sliding on edges) are present in this version, yet absent in the Saturn version. This almost leads me to wonder if the Saturn version uses a custom engine instead as it runs completely different from the PSX version. Numerous resources that exist in the Saturn port, things such as Green Chaos Serpents, gibbing enemies, slight level differences from the PSX port, an overall smoother framerate that goes up to 60HZ and faster scripting times are just a few of the things I've observed so far. Also along with the fact that I can't find any Doom engine "traces" anywhere in any of the hex of the Saturn port (outside of sound and texture names, which could easily be converted to a new engine retaining their original names) is also eye opening. Those module names that I pointed out earlier at the end of 0.BIN also point to a different game engine, as no module names like those exist in the PC source code of Hexen.

EDIT: The only Doom engine like thing that I have encountered thus far in the Saturn port is wallrunning. Perhaps not an all new engine was used, but maybe a heavily modified PC version engine?

Lastly, whereas PSX Hexen is using the same game engine as the PC version (or an earlier variant), the game is definitely using the same way to render levels as PSX Doom by using LEAFS. Considering how resource intensive it is to render the levels that way, it suddenly makes sense as to why scripting is so slow in this version as drawing that many quads PLUS handling changing level architecture via scripting must be extremely taxing on the system. It would almost make sense for the Saturn version to use a different engine as we all know how an almost straight port of the PSX version to the Saturn turned out...

So there you have it, what do you think sirs?

So...what engine does the N64 version use?