Chade on 22/2/2008 at 20:58
Hi All,
I am just starting to learn T3Ed. I am interested in creating a mission that takes advantage of some of the unique aspects of thief 3 (mainly dynamic shadows, and the climbing gloves). There is a considerable possibility that I will never find the time to complete a mission, but hey: there's always room for hope! :)
I am going through Komag's tutorial now, and am a bit concerned about the emphasis he places on optimization.
For instance: I would like the vast majority of my objects to cast shadows. There won't necessarily be many lights in a scene, but I would like most objects to cast shadows, in case a guard with a torch should happen to wander by. My question is: will objects which cast shadows incur a performance hit if they are currently outside the radius of any lights? Also: how bad (on today's hardware) is the performance hit of a shadow in any case? Do I really have to be as worried as Komag suggests?
Also, I have the same concern with physics. I would like all objects to behave consistently. I may stick a barrel high up on a shelf and out of the way, but if the player decides to get it down (say, with a fire arrow, or by jumping and blackjacking it), I don't want the player to go to all that effort and be disappointed. So: is it really a big performance hit to have a lot of objects which are physically simulated?
Any advice appreciated,
:)
Beleg Cúthalion on 22/2/2008 at 21:43
To make a very short statement to this: Since the computers became faster lately, you can assume that every map with a similar concentration of shadows and moveable objects like you find in the original maps (and there are many I think) will run well even if it is two times bigger than the TDS missions.
I don't think you need a lot of shadow casting objects, only if it would look strange if there was none. But the experts around here will give you better answers.
Ziemanskye on 22/2/2008 at 22:18
As far as I know, shadowcasting objects are mostly a memory hit when they're not being touched by shadowcasting lights.
(shadows have a seperate vertex pool: I don't know how smart the system is overall, but impressions are generally towards "retarded" when it comes to TDS and file-structures)
So while there's no light, it shouldn't hurt things much: you may want to not have too much detail just in case though (OM-level = fine, my overkill approach, not so much so).
As for physics: they're pretty cheap, except that it means a lot of extra properties floating about, and we do have a (hard) limit on them somewhere out there, but I think Nomadofthepacific is the only person to have ever actually hit it. They're expensive when they're moving, of course, and if a lot of things can all hit each other and set them off that can cause a lot of problems, but once they stop again it goes back to not costing that much (that's one of the big secrets to how they can do these things at all ;) )
In either case: yes, you need to be paranoid about performance (it's a good habit anyway), but it's general visibility that's going to cause the grief, not specific effects. Aim for a relatively low object/smesh density and you'll probably be okay though: people won't complain - on the contrary, emptier missions often get praise for being more historically appropriate and more "classic Thief" anyway.
(I'm a polygon whore: I love the fact I can have the density of stuff, but I know that means I don't get many dynamic shadows or physics effects, and I have to keep the NPC count a little low)
Chade on 22/2/2008 at 22:50
That's cool ... my tolerance towards spending time adding lots of detail which won't affect the game play is pretty small. I could never be a professional level designer! Expect any mission I make to be relatively boring, visually ... :erg:
Ziemanskye on 23/2/2008 at 10:25
Boring is a relative thing: people *like* interactivity, so dynamic lights/shadows and physics-stuff is likely to get you a lot of praise, since most of the TDS FMs don't make much use of them.
It depends on who you ask which is better: a notice board that has a lot of stuff stuck to it, or one that swings when you bump it (or slides out the way when you press a button, or whatever)
Chade on 23/2/2008 at 11:34
Well, thanks for the encouragement!
I don't want to get my hopes up too far, though. All this assumes that it's actually possible to design a level, which on one hand is open-ended, and on the other hand is designed so the player will choose to use dynamic lighting and shadows as tools to progress through the level. There are a lot of barriers to getting the player to use dynamic shadows as tools. Just consider how slow, difficult, and noisy it is to push a barrel across a floor, in order to create a shadow. It's difficult to imagine the player ever wanting to do this. I might have to take a different tack, and force the player to react to dynamic lighting/shadows, rather then pro-actively use them. But I would be a bit disappointed if I had to do that.
I know I can design set-pieces where the only possible option is for the player to use physics and dynamic shadows to proceed. That's easy. But it doesn't really respect the spirit of Thief ... and the whole point of this level is to showcase the spirit (and unique features) of Thief 3.
Anyway, it will take some experimentation to get it right. I hope I have the time. I doubt I will get much done before I finish my honors half way through this year ... but after that, who knows ...
Ziemanskye on 23/2/2008 at 13:48
Remember that the NPCs can't see through static-meshes, even if the player is fully lit behind them: it may be worth experimenting to see if that still applies to "junk" objects (things you carry in front of yourself), since otherwise your pushing the barrel idea is a bit moot: if you have to move the barrel to create the shadow to hide in, you're exposed while you move the barrel anyway (and the sound of it moving will make people look that way anyway).
A more practical idea might be a more mechanised facility: things moving when buttons are pressed to create a more normal puzzle out of the lights/shadows. (And that might fit better with a more electric-lit level anyway: flame lights tends to mean players wanting water-arrows - and it's more Thief to turn lights off than to create shadows to hide in while the light is still lit, hence why the dynamic shadows aren't used much; technology limits as defacto gameplay)
Chade on 23/2/2008 at 21:11
I agree, some sort of Keeper factory is the ideal setting. Also, to create strong dynamic shadows you need areas that are fairly brightly lit from just one or two strong lights sources. To me, that calls for electric lights as well. Torches bring to mind a darker dirtier level.
One way of making it easy to use normal barrel/crate type objects to create shadows, is to have (extremely) low lying lights. Then even a small throw-able object will create a large shadow, enabling the player to just chuck small crates around and create shadows.
The best approach might be to cycle between different settings:
The grimy city streets with guards carrying torches.
The factory with puzzle based dynamic shadow gameplay.
The garden areas with low lying garden lights, and freeform dynamic shadow based gameplay.
Well, that's about all I can think of for now!
