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Interesting. I recall Prey being the first game to hype portals for rendering, though I think theirs may have been for drawing not just culling? Does anyone kno

Interesting. I recall Prey being the first game to hype portals for rendering, though I think theirs may have been for drawing not just culling? Does anyone know how it worked? Dark Forces apparently also used portals for culling, IIRC.

to11mtm 2y ago
I think Build used some form of portals as well... primarily for water/underwater transitions, but there was at least one level in Duke3d that used it for some non-euclidian geometry.
- d3VwsX 2y ago
  Pretty sure water was just a teleporter? You may be thinking about the mirror effect? I think that was a kind of a portal effect. You had to make a large empty section behind each mirror that was used by the engine to render a mirrored copy of things in front of the mirror. You could make some weird impossible geometries by just superimposing sections. Two sections could occupy the exact same coordinates, but movement and rendering were done across edges shared by sections and did not care about if there was some other section in the same space. As long as there was never a way to see those sections at the same time.
  - CyberDildonics 2y ago
    Pretty sure water was just a teleporter? You may be thinking about the mirror effect? That's what they just said? They didn't mention the mirror effect? The mirror effect was done with duplicate geometry? It occupied the overlapping space of what was behind it? The build engine also didn't have vertical levels.
    - paulryanrogers 2y ago
      Shadow Warrior (Build) did have some room over room stuff. But IIRC it still leveraged offset sectors like Duke's water. FWIW some modern Doom ports appear to have this as well, at least with levels that support it.
  - Sharlin 2y ago
    A teleporter is just a portal that you can’t see through. > You could make some weird impossible geometries by just superimposing sections. Two sections could occupy the exact same coordinates, but movement and rendering were done across edges shared by sections and did not care about if there was some other section in the same space. As long as there was never a way to see those sections at the same time. This is exactly what portals are.
- smitelli 2y ago
  E2L11 “Lunatic Fringe.” The map has an outer ring containing 720 degrees of hallway. Surprisingly disorienting even when you know that’s what’s going on.
phire 2y ago
No. Prey was one of the first games to hype portals and non-euclidean maps for gameplay. Portals for rendering date back to the dawn of 3d graphics and many early FPS engines used the concept. But these portals were only there as a rendering optimisation. While you could abuse them to make non-euclidean maps, the tools were intended to make proper maps, and the portals would be invisible to players.
- smolder 2y ago
  Marathon 2 by Bungie also had weird non-euclidean maps with overlapping sections in the late 90s I think. I miss the customizability of that game. Early bungie works were up there with early blizzard or early valve. They sold a tool for fun instead of casting a bait for profit.
  - Terr_ 2y ago
    I recall that some of the developer commentary for either Portal or Portal 2 mentioned that they began level-development by using a special version of the namesake non-euclidean Portals to connect different chambers and hallways that were being developed in parallel. [Per distinct loading-screen level.] Then, later in development, they ran a tool to stitch together all that geometry in a more-normal way, and they only had one case of impossible-overlap, which continued to use the non-euclidean link. _________ Edit: Found it: > [...] When we started the project making any big structural change in a level or the order of levels would lead to hours or even days of busy work trying to reconnect things and make sure they lined up again. If we ever wanted to ship something the size of Portal with the finely tuned balance we desired then we needed a way to be able to make big changes to the layout of the game without paying the cost of making everything line up again. We needed a way to bend space. We needed to think with portals. Using portals to connect different areas in the world we could make any type of impossible space work out. You could look through a hallway into the next room but the hallway might be on the other side of the map and the room you are looking into might be in a completely different orientation. We could seamlessly insert an elevator, a huge expansive vista, a room that was bigger on the inside than the outside, or even create an infinite fall by connecting a shaft back into itself. Soon every connection between any space was a portal. We would even switch them on the fly. Even a simple door worked like the cartoons - just a facade painted on a wall that seamlessly opened somewhere else entirely. Once the game settled down we were able to finalize our path and remove all of the world portals. There's only one impossible space left in the whole game - see if you can figure out where it is. -- "World Portals". Portal 2 developer commentary
corysama 2y ago
> Dark Forces apparently also used portals for culling, IIRC. DF used BSP for culling. But, I made a mod level long ago playing with features and made a stairway in the middle of a room that you could only see from in front of it. It was some kind of free-standing portal with no surrounding support. Fun fact: the creator of the DF engine told me he based it on a reverse engineering of a beta release of DOOM. Apparently, the final release of DOOM cut a lot of engine features to gain speed. But, DF shipped with them and maybe a few more.
- paulryanrogers 2y ago
  > Fun fact: the creator of the DF engine told me he based it on a reverse engineering of a beta release of DOOM. Can you provide a source? As I understand it DF is based on the (pre release?) Tie Fighter engine, and DF began production before Doom released. That's why for example DF has some non-textured 3D models like the turrets and mouse droids. I follow The Force Engine (reverse engineered fan port) and Dev Game Club (hosts worked at LA). Supposedly DF devs did see Doom (perhaps even a pre release version), but already had their own tech working by that point. > Apparently, the final release of DOOM cut a lot of engine features to gain speed. Doubt. There's a lot of interviews with the ID guys, and I don't recall anyone saying they cut significant technical features. They made Doom in only 13 months, minus almost a month to port Wolf3D to SNES. Maybe Carmack -- or the released alphas and betas -- can clarify? Or perhaps you are confusing some of the Doom porting efforts, which did cut down levels and sometimes features significantly.
  - corysama 2y ago
    > Can you provide a source? All of this the DF engineer told me face to face. Might have been based on an alpha version of DOOM. He might have already had some tech for DF before studying DOOM. It was a casual conversation over ten years ago. I don't recall what the changes were. Something about being less flexible to be faster. Only way to know would be to redo the reverse engineering of the BSP format from one of http://toastytech.com/dooma/ http://toastytech.com/dooma/
bluedino 2y ago
Descent used portals
adastra22 2y ago
As mentioned by others, Descent used portal rendering all the way back in 1995. It's a simple trick that only requires an alpha mask, which even the earliest hardware supported. But certainly the game Portal (2007) hyped using portals for rendering prior to Prey.
- usea 2y ago
  > But certainly the game Portal (2007) hyped using portals for rendering prior to Prey. They were referring to Prey (2006).
  - deleted 2y ago
    [deleted]
  - Tempat 2y ago
    Also worth noting that Prey (2006) started development in 1995.
    - keyringlight 2y ago
      There are a handful of videos from E3 (97 or 98) showing off the original 3DRealms development of Prey. One of the things that didn't survive into Human Head's version on the Doom3 engine was rotating portals, or if they did they were rare that I don't remember them.
- bananaboy 2y ago
  Original Descent was software rendered though.
  - adastra22 2y ago
    2D graphics cards had alpha masking.
    - rep_lodsb 2y ago
      But not standard VGA.

to11mtm 2y ago

I think Build used some form of portals as well... primarily for water/underwater transitions, but there was at least one level in Duke3d that used it for some non-euclidian geometry.

d3VwsX 2y ago
Pretty sure water was just a teleporter? You may be thinking about the mirror effect? I think that was a kind of a portal effect. You had to make a large empty section behind each mirror that was used by the engine to render a mirrored copy of things in front of the mirror. You could make some weird impossible geometries by just superimposing sections. Two sections could occupy the exact same coordinates, but movement and rendering were done across edges shared by sections and did not care about if there was some other section in the same space. As long as there was never a way to see those sections at the same time.
- CyberDildonics 2y ago
  Pretty sure water was just a teleporter? You may be thinking about the mirror effect? That's what they just said? They didn't mention the mirror effect? The mirror effect was done with duplicate geometry? It occupied the overlapping space of what was behind it? The build engine also didn't have vertical levels.
  - paulryanrogers 2y ago
    Shadow Warrior (Build) did have some room over room stuff. But IIRC it still leveraged offset sectors like Duke's water. FWIW some modern Doom ports appear to have this as well, at least with levels that support it.
- Sharlin 2y ago
  A teleporter is just a portal that you can’t see through. > You could make some weird impossible geometries by just superimposing sections. Two sections could occupy the exact same coordinates, but movement and rendering were done across edges shared by sections and did not care about if there was some other section in the same space. As long as there was never a way to see those sections at the same time. This is exactly what portals are.
smitelli 2y ago
E2L11 “Lunatic Fringe.” The map has an outer ring containing 720 degrees of hallway. Surprisingly disorienting even when you know that’s what’s going on.

phire 2y ago

No. Prey was one of the first games to hype portals and non-euclidean maps for gameplay. Portals for rendering date back to the dawn of 3d graphics and many early FPS engines used the concept. But these portals were only there as a rendering optimisation. While you could abuse them to make non-euclidean maps, the tools were intended to make proper maps, and the portals would be invisible to players.

smolder 2y ago
Marathon 2 by Bungie also had weird non-euclidean maps with overlapping sections in the late 90s I think. I miss the customizability of that game. Early bungie works were up there with early blizzard or early valve. They sold a tool for fun instead of casting a bait for profit.
- Terr_ 2y ago
  I recall that some of the developer commentary for either Portal or Portal 2 mentioned that they began level-development by using a special version of the namesake non-euclidean Portals to connect different chambers and hallways that were being developed in parallel. [Per distinct loading-screen level.] Then, later in development, they ran a tool to stitch together all that geometry in a more-normal way, and they only had one case of impossible-overlap, which continued to use the non-euclidean link. _________ Edit: Found it: > [...] When we started the project making any big structural change in a level or the order of levels would lead to hours or even days of busy work trying to reconnect things and make sure they lined up again. If we ever wanted to ship something the size of Portal with the finely tuned balance we desired then we needed a way to be able to make big changes to the layout of the game without paying the cost of making everything line up again. We needed a way to bend space. We needed to think with portals. Using portals to connect different areas in the world we could make any type of impossible space work out. You could look through a hallway into the next room but the hallway might be on the other side of the map and the room you are looking into might be in a completely different orientation. We could seamlessly insert an elevator, a huge expansive vista, a room that was bigger on the inside than the outside, or even create an infinite fall by connecting a shaft back into itself. Soon every connection between any space was a portal. We would even switch them on the fly. Even a simple door worked like the cartoons - just a facade painted on a wall that seamlessly opened somewhere else entirely. Once the game settled down we were able to finalize our path and remove all of the world portals. There's only one impossible space left in the whole game - see if you can figure out where it is. -- "World Portals". Portal 2 developer commentary

corysama 2y ago

> Dark Forces apparently also used portals for culling, IIRC. DF used BSP for culling. But, I made a mod level long ago playing with features and made a stairway in the middle of a room that you could only see from in front of it. It was some kind of free-standing portal with no surrounding support. Fun fact: the creator of the DF engine told me he based it on a reverse engineering of a beta release of DOOM. Apparently, the final release of DOOM cut a lot of engine features to gain speed. But, DF shipped with them and maybe a few more.

paulryanrogers 2y ago
> Fun fact: the creator of the DF engine told me he based it on a reverse engineering of a beta release of DOOM. Can you provide a source? As I understand it DF is based on the (pre release?) Tie Fighter engine, and DF began production before Doom released. That's why for example DF has some non-textured 3D models like the turrets and mouse droids. I follow The Force Engine (reverse engineered fan port) and Dev Game Club (hosts worked at LA). Supposedly DF devs did see Doom (perhaps even a pre release version), but already had their own tech working by that point. > Apparently, the final release of DOOM cut a lot of engine features to gain speed. Doubt. There's a lot of interviews with the ID guys, and I don't recall anyone saying they cut significant technical features. They made Doom in only 13 months, minus almost a month to port Wolf3D to SNES. Maybe Carmack -- or the released alphas and betas -- can clarify? Or perhaps you are confusing some of the Doom porting efforts, which did cut down levels and sometimes features significantly.
- corysama 2y ago
  > Can you provide a source? All of this the DF engineer told me face to face. Might have been based on an alpha version of DOOM. He might have already had some tech for DF before studying DOOM. It was a casual conversation over ten years ago. I don't recall what the changes were. Something about being less flexible to be faster. Only way to know would be to redo the reverse engineering of the BSP format from one of http://toastytech.com/dooma/ http://toastytech.com/dooma/

bluedino 2y ago

Descent used portals

adastra22 2y ago

As mentioned by others, Descent used portal rendering all the way back in 1995. It's a simple trick that only requires an alpha mask, which even the earliest hardware supported. But certainly the game Portal (2007) hyped using portals for rendering prior to Prey.

usea 2y ago
> But certainly the game Portal (2007) hyped using portals for rendering prior to Prey. They were referring to Prey (2006).
- deleted 2y ago
  [deleted]
- Tempat 2y ago
  Also worth noting that Prey (2006) started development in 1995.
  - keyringlight 2y ago
    There are a handful of videos from E3 (97 or 98) showing off the original 3DRealms development of Prey. One of the things that didn't survive into Human Head's version on the Doom3 engine was rotating portals, or if they did they were rare that I don't remember them.
bananaboy 2y ago
Original Descent was software rendered though.
- adastra22 2y ago
  2D graphics cards had alpha masking.
  - rep_lodsb 2y ago
    But not standard VGA.