Wanted: People who know more about Marathon than is healthy

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ravenshining
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One thing that might bear keeping in mind is that lights may be used as a way of displaying one surface as intrinsically having a darker colour than another. For example, the door to the first terminal on Eat It- there's clearly no reason why it should possibly be illuminated differently, it's just a darker shade of grey than the rest of the wall.
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treellama
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Alex wrote:Yeah, I might have a look at some of the doom source ports, IIRC some of them added fairly complex lighting so they would have run into similar problems. I dont think dooms lighting was as complex as marathons tho, so maybe their solutions wont quite work here. Especially with how to light 3d models added to the scene.
The purist way is just to emulate the floor/wall/ceiling lights directly by blending the textures, which I assume Unity is capable of doing. Add a miner light as a point source. You don't have to split walls into strips, like Aleph One's OpenGL (Classic) renderer does, which is nice! Light sprites and models the way Marathon does, based on the floor light. Maybe put a diffuse light shining down based on the floor light of each polygon? Not sure how well that will work with light and dark polygons next to each other, or how well it will work with the texture blending. Baby steps. Gonna need lots of tweaking.

At some point you can get some dedicated fans to create a lightmap for each level, and then don't use the original data at all(!). I would put that at the end of your list after "game is actually playable". You'll still need to emulate the original lighting for all the third party maps out there.
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treellama
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If you can't get 5D space to work, though, it's all for nothing. That seems like a priority. It's also the one thing I really don't understand how to solve in Unity.
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Alex
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Yeah, im going to go with just applying a shadow map that covers each wall/floor of greater/lesser intensity to exactly match the way marathons lights work initially. I've just about got the liquid volumes generating, which is i think the last of the 3d stuff that needs making.
After that i will hook up the switches to the platforms so that the player can walk around the map and open doors etc, then its on to the impossible space, which im actually pretty confident will work.
Basically i have 2 approaches. Since im making each marathon polygon as an object unity, i can turn them on and off, so what will happen is that most of the level will be turned off, and i only turn on the polygons that the player can see. (so the algorithm is essentially, draw the polygon the player is in. if there is a transparent wall showing, then draw the polygon that connects to as well, repeat until there are no more transparent walls on the screen.)
If for some reason that does not work, i can go down the render to texture route which is to point a camera at the connecting polygon from where the player is, and then render that to a texture, which is then drawn doorway to the next polygon, and repeat that for each connected polygon in turn, which almost recreate a portal based render system within unity. although that would probably be rather expensive to render so i would have to only use it where there is overlapping geometry,
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treellama
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For either of those approaches to work, you'll basically need to recreate Aleph One's visibility calculations (sort polygons, fire rays to determine clipping planes, set up clipping planes and render far to near). I wonder if it's possible to do that without introducing all the limitations as well.
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Alex
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Are any of marathons limitations actually due to is portal based nature tho? I cant see any reason why, down the track you coudnt have the rooms connecting vertically as well as horizontally and allowing for true 3d maps. As an added bonus it should also only end up only handling the geometry for a small part of the map at any time, so it should be possible to create maps of an essentially unlimited size.
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