Half-Life style level transitions

I went and gone done made an example WAD for my method of creating seamless level transitions. It's up on my Google Drive, but it's also pending approval on /idgames too.

The text document with the archive explains the usage and things that cause it to break. And yes, it does break easy. They're the very definition of what I call "fragile scripts" as any slight change or forgotten important detail causes the entire thing to break. And by break, I mean anything from disorientation to spawning outside of the map.

As such, I really only recommend attempting to refactor the scripts for your own nefarious ends if you're well versed in ZDoom and ACS. Everyone else, I recommend waiting for the in-engine solution I have in mind.

I might be remembering incorrectly, but I think DTS-T did this?

http://www.doomworld.com/idgames/?id=17037

Probably remembering incorrectly. What I did see from what I played of it was ye olde "Start position in very close proximity to where you left the last map". The method I employ here provides a mechanism for matching where you exited and where you enter.

How is this different from simply using hexen's hub system?

I don't think you fully understand Hexen's hub system if you're asking that question. Hubs exist simply to track states between levels. This effect can be used in a hub-less linear level set. All that is required is to define no intermission in your mapinfo.

Assuming you've duplicated geometry correctly, this will place you in the exact spot you left the last map from, which is beyond the Hexen code's abilities (but not some ACS trickery).

The example uses a hub, though. Just for extra points mainly.

Starting each new level from a stationary position would be preferable to starting a level being flung forward.

I don't know if this is possible, but I think the effect would be greatly enhanced if you could keep the player's direction and position, while removing their momentum.

Certainly a neat trick though.

KiiiYiiiKiiiA said:

Starting each new level from a stationary position would be preferable to starting a level being flung forward.

I don't know if this is possible, but I think the effect would be greatly enhanced if you could keep the player's direction and position, while removing their momentum.

I believe the parts of the scripts dealing with velocity are optional. For my part, I feel the momentum is an essential part of the illusion. If the player is running across the exit area in the first map, but starts the new map at a stand-still, it destroys the seamless nature of the transition.

andrewj said:

How is this different from simply using hexen's hub system?

The hub system does not assure that the player will start a map at the exact same spot with respect to the adjacent geometry as the previous map. In Hexen, for example, the transition from one map to another in a hub was achieved by (typically visible) teleporters, and the player was starting in an area that most likely looked quite different from the end area of the previous map. This is not considered a "seamless" transition, and it wasn't even required. However, in Half-Life (and in some DooM mods), to make things realistic-looking it was necessary to allow the player to move from one map to another without realizing that the transition had occurred. The example GooberMan has provided illustrates this concept.

ReX said:

I believe the parts of the scripts dealing with velocity are optional. For my part, I feel the momentum is an essential part of the illusion. If the player is running across the exit area in the first map, but starts the new map at a stand-still, it destroys the seamless nature of the transition.

I noticed that after the next level loads I have to press the "forward" button again to continue moving. So it will not be seamless in any case unless you can find some workaround for that.

ReX said:

it was necessary to allow the player to move from one map to another without realizing that the transition had occurred. The example GooberMan has provided illustrates this concept.

But I see the "loading" message and there is a very noticeable lag when the new level loads. I don't think you can fully hide the transition.

But is still transits player only and no monsters/items may be let in the transition zone, right? So, while neat, it's still not like in half life.

Memfis said:

But I see the "loading" message and there is a very noticeable lag when the new level loads. I don't think you can fully hide the transition.

Agreed. Plus, the larger the new map, the longer it will take to load. But, all things considered, I'll take GooberMan's method to the alternatives.

Scypek2 said:

But is still transits player only and no monsters/items may be let in the transition zone, right? So, while neat, it's still not like in half life.

You are correct - player(s) only. GooberMan did discuss the issues, but limitations continue to exist.