Free Form Thief-like World

[Dram]

oh boy, now i'm lost

[Domarius]

I agree I oversimplified Spar, but my concern is still valid. There would be no point in vis portals if we just left it all up to polygon occlusion (wether done by the renderer or the video card).

[Dram]

well anyways, i just realised you can have a moving platform and have moving visportals, so its all good

 

at least i remember them working, i'd better test that again.

[Gildoran]

I was under the impression that the way polys are culled was as follows:

Doom first figures out which visportal areas can be seen, using overlapping screen-space.

Anything in those visportal areas which isn't cut out due to scissoring is then sent to the graphics card.

The graphics card makes an initial pass through the polys during which it only renders to the depth buffer.

Then it makes a second pass through the polys, rendering all the normalmapping/specular/shiny-stuff, using the depth buffer on a pixel-by-pixel basis to figure out if it should do the calculations for any given pixel.

 

What I'm worried about, is that although the lighting/etc might not be done on the surfaces inside the ship, I figure that if it's large and detailed enough, having to calculate the positions of hundreds of thousands of polies (due to lack of visportals) could put a load on the computer and/or graphics card.

 

Edit: You can have visportals on movers? I need to test that out... I had always assumed they only worked with BSP geometry. If they do work with movers that'll be really cool.

[Domarius]

Yes I thought Doom sends the video card every poly in the current visportals too.

[bob_arctor]

Interesting conversation by the way. Like it.

No I just mean a steampunk giant airship mission, with cheating for the city... let me see...

 

could be a 3d skybox that the airship moves above and around

 

could be a simple city on a monorail course so the airship is stationary

 

or just "It's foggy" like in T2X train sequence .

 

But I just want to be able to sneak around the nobles in a a big airship party, maybe get into the gas balloon for a while.

[Dram]

actually, im experimenting with various ways to get a city scene to run fast, even when its huge and viewed from above. I'll post my results when i manage to get a good fps going.

[Maximius]

I see someone's played Redguard

 

I loved that game, it ruled. And yes that would be an excellent idea. You could even have the city pretty much flat and have the ground as one texture which has no lights or what not, but is a screenshot of the other city from above. That would boost fps tenfold.

 

Prey sounds pretty damn good too, i might get that.

 

Sorry I never played RedGuard Dram but I will have to check it out. That screenshot sound like the trick, throw some clouds in and the illusion would be solid. I think.

 

@Maximus: IMHO, doing an airship would be tricky. One thing I haven't seen many people mention about airships is the level of detail in the airship. You're a lot more limited if you want to be able to interact with the city around you while you're on the airship. With an unmoving (i.e. docked) airship, the game can use visportals to only render the parts that are visible (e.g. if you're on the deck, there's no need to render the hold below, and vice versa). This would allow you to have a much larger, more finely detailed ship with elaboratedly decorated rooms below deck. For a moving ship, there's a couple of ways you could do it. The most obvious way would be to implement the ship like a giant monorail that is actually physically moving through the level, but that has the problem that it'd be difficult or impossible to apply optimizations like visportals. So the entire ship would probably be rendered, which limits how big/detailed it could be. You'd probably want to omit indoor rooms on the ship. Also, I worry about how well AAS (AI awareness system) handles moving platforms. Would guards on the ship accidently walk off it? IIRC, notice that the only person on the monorail in D3 sat in one place while it was moving. But I don't know much about AAS so maybe my concern is unfounded. What I would be inclined to do, is make the ship unmoving, then use scripting and sky_portals to provide the illusion of the ship moving throughout the city (in other words, have the ship stay in one place, but use a camera that moves through the city to paint the backdrop). Of course, this has the disadvantage that you can't interact with the city around you. For example, you couldn't fire at guards on a "nearby" roof-top and they couldn't fire at you (or even see you), since they're in an entirely different part of the level and only appear to be nearby. So you'd probably want to avoid situations like that, and have all the gameplay take place on the ship. Or you could combine the sky_portal idea with some archer-laden roof-tops that physically move by the ship in sync with the camera of the sky_portal. This has the disadvantage that it's a little more complicated, though it could spice up gameplay. If your city is low-poly enough that the entire city can be viewed without a drop in frame-rates, you could take a third option of keeping the ship still, and having the city be the "monorail".

 

I don't claim that the above is a comprehensive list of ways of implementing an airship, but hopefully it'll give you a few ideas about possible limitations of the D3 engine.

 

Thanks for your information. I had another idea for air ships, let me float this one by you.... ( )

 

Ok, the story line is that the Thief is aboard one air ship which is under attack by another air ship. The second air ship is attempting to board the first, so there are a number of grappling hooks and chains joining the two ships. The first ship is doomed, its on fire and will be going down soon. The Thief has to sneak from the first ship, avoid the battling crews, shimmy across a chain, and hide on the second ship to avoid going down with the first.

 

To build the map, all you would need as far as non-ship environment is a cube with five sides of "sky" and one indistinct side of "ground" The two ships are actually one object, joined by a number of chains, though it wouldbe neet to have the 2nd ship drop its chains after a certain point but whatever. The ships dont have to move, or at least much, they could rock back and forth for effect.

[Dram]

now that would be much simpler.

 

You could still attempt to creata a city below them, it only has to be relatively low res, it'd be for effect.

[Maximius]

now that would be much simpler.

 

You could still attempt to creata a city below them, it only has to be relatively low res, it'd be for effect.

 

That would be fun, the player could even be made a little nauseous looking down towards the city if the rocking were bad enough, talk about realism!

 

 

Gildoran:If your city is low-poly enough that the entire city can be viewed without a drop in frame-rates, you could take a third option of keeping the ship still, and having the city be the "monorail".

 

 

Ok so how about the map, the giant City, has three levels? 1. the ground floor, with active streets and small homes and shops and sewers to explore. halfway up the tallest buildings is a level portal to 2, the second half of the buildings and rooftops, wizards towers and thieves nests, level 1 being a low rez floor below if you look over a ledge or window and the sky being a slightly higher low rez roof. Now at certain rooftops there are air ship stations where the Thief can sneak aboard a docked ship, which then kicks off 3, a leisurely journey to another air station across the City. This 3 could be a "city monorail" with the rooftops well below the ship so they could be pretty low rez, the ship could be detailed and explorable, robbing guests and crew and stuff, then docking across the city, level portal, back to 2 but at a different site of course. When the Thief wants to head back across the city, he could sneak back aboard, perhaps randomizable guests and guards and other foes could be generated for a different trip each time.

[Dram]

i guess that could work yeah

 

even better would be to put teleports when lets say entering a tower (the player wouldnt notice tho) which teleports you to another part of the map, but with a simple city. This way you could easily make the crazy airship above the city.

 

also, ish said something about the ai being able to be set to be rendered all the time (instead of going idle if not in the same area) so that in this case guards on the other side of the map would still do their patrols.

 

anyways, all this is talk but no walk lol, its time to do a few tests i think

 

i'll post results later, it'll take a long while tho, as you can imagine.

[Maximius]

Im looking forward to your results. The teleporting thing is cool, it would beat having an assload of level portals to wait for all the time.

[Dram]

yeah definately. and it would achieve the same effect, but instead of constantly loading new levels, it would load the whole thing at the start, which would take long, yes, but then there'd be no more loads after that.

 

anyways, atm im making the buildings that i'll use for the city, after that i'll do the roads etc.

[Dram]

just a little update on what i've been doing, so you know im not a bludger

 

cityscape

 

not much yet, but i've been developing the buildings, so here they are.

 

obviously this is not as grand as doom3 can make it look, but we're trying to keep as much performance as possible, and at the same time be able to see a massive city.

 

--Dram

[sparhawk]

Aren't these to many lit windows? I suppose our game usually is in the middle of the night, where I would expect most windows already unlit, because people are sleeping already.

If the buildings are not enterable it doesn't really matter, but this looks like a pretty busy street to me. With so many lights lit, I would either expect a 24 hour shift business there, or many people still on the streets and awake.

[bob_arctor]

A bludger mate?! Don't think so!

 

An ozzieism if ever I saw one.

 

I'm impressed, that looks like a city mission type city to me, and quite detailed for one at that, for someone used to TII missions there is a lot of detail, for a low detail city I just expected some textured boxes, with crappy textures, those are very nice.

 

Make the game FASTER. I want to be able to walk those screenshots. I get the same feeling with STALKER, however you guys seem to work faster than them.

[Ombrenuit]

The lights and the sky on that mission...I just love the atmosphere. Keep up the good work!

[heXen]

to bob actor - LET THEM MAKE THE GAME!!!!!!!

 

You know why games become worse and worse today? You have any idea, at least? The people require graphics, graphics, graphics, but they also want it fast fast. What comes in the end? A company does a game with great graphics, it does the game in 1-1 and a half year, but the game has zero gameplay and consists of 3 levels. I personaly have some hopes for this mod, and, like they said, I wouldn't mind if they done it for 6 years. Have patience, and the game will be great, speed up them, all you have is graphics...

[Dram]

lol, thanks guys. yeah, its gonna be a city.

 

@Spar: it does'nt look too great in screenshots if half the city is sleeping

 

Besides, it'd take about 5 minutes to change it so most of the windows are unlit.

[Dram]

well, just had a look again ingame, yeah there are too many lit hehehe. Well, i'll tone it down later.

[Maximius]

It looks really good Dram. I cant wait to be perched on one of those arches lining up a bow shot at someones head...

[nethawk]

From the sounds of it it looks as though you're asking for something in the spirit of the upcoming Oblivion title. Very sweet game - reminiscent of Thief. major drawbacks include load zones between indoor/outdoor cells, focus on gameplay other than pure Thief (though it's possible). I'm still going nuts for Dark Mod however when it comes out.

[Dram]

yeah, apparently oblivion still renders ai even though you're inside and all, so the guards can in fact chase you in lol.

[sxotty]

This seems like a very large diversion from the main thrust of youguys project. But yeah it is pretty interesting.

 

How would you control the moving up and down? If you did it by changing the mass would the physics work correctly? (Nevermind they won't as of now). But it would be nice to make it wallow horribly as airships are not the most responsive things ever.

 

I think the idea of having landing spots designated is good, you could do it this way.

 

Remember the skybox bloodrayne made? Well just have two one for when you look up from the ground, and one looking down from the sky in other words you have one arched above you and one below you and the levels are completely physically disconnected so you teleport like you were saying. Although loading levels might not be terrible either and man you could use it to navigate the city.

 

And if player mods were a certain quality you could just put a stop on the main sky map that lets you off into their mission sequence... nifty

Edited October 20, 2005 by sxotty

[Maximius]

yeah, apparently oblivion still renders ai even though you're inside and all, so the guards can in fact chase you in lol.

 

 

Is this something the D3 engine could NOT do? Id hate to escape a guard by running through a teleport or something.