Doom !!!

#1 Wow, those are some nice shots.

#2 bores the hell out of me.

It'll be needing the old GF4/5/6 anyway :))

Phil.

#3 What does it use if not BSP trees?

#4 this little thing called "hardware" :) BSP tree solutions like Quake derived games / clones use(d) was a solution to the problem of NOT ENOUGH. Not enough memory, not enough CPU, etc.

Now days memory is plentiful, CPUs are overpowered for anything but scientific work or broadcast/film quality rendering and similar compuations.

#5 How do you know it doesn't use bsp trees? Did someone from id software say this?

#6 Tim:

Read the article instead of drooling over the screenshots (all 3 pages). It's in there :-)

#7 BSP is mainly used to tackle 'not enought fillrate' problem, not cpu/nor memory problem. and yes, fillrate is always a problem regardless how powerful is your machine.

#8 Yeah I read that in the article, it just sounded more like the author guessing to me.

-Tim aka Spock

#9 I can't find a link, unfortunately, but I remember reading about Doom 3 doing away with BSPs quite some time ago. Mostly because they take too long to generate, which doesn't work well with the fact that the tools to edit content for the game are now integrated directly in the engine (so real-time changes to world geometry are supported, at least when in 'edit-mode').

With a game like Doom3 where you pretty much require a GF3 or higher to run well, it is actually true that BSPs dont buy you much and in many cases will just slow things down. With that kind of hardware on the card you're better off just using vertex buffers well and doing very high-level culling using portal/sectors or similar methods..then just throw the rest of the polys at the card, preferably front to back and let guard band clipping and hardware assisted occlusion do the rest.

I believe Doom3 is using portals as the primary method of vis/culling, though I can't guarantee that's true.

#10 While BSP trees may be fast, they place a lot of limitations on what you can do. There were pretty major work-arounds done in quake1 to compensate for the limitations of BSP trees. BSP is one of the many methods out there for determining visible polygons. It is certainly not the be all and end all of 3D tech.

#11 Ok people, I wasn't asking for some sort of culling primer or something. You can't "use hardware" to simulate the effect of BSP trees. There isn't some handy bit you can flip that says "do collision detection for me and also cull things efficiently please!"

So my question was "what do they use instead?" I guess the answer is "he didn't say." So who knows? Maybe portals, maybe some sphere based approximations, whatever.

#12 From what I've seen, it's mostly indoors locations, so portals would seem the likely choice. Q2 used portals, with BSP trees for the rooms, but I'm guessing that Doom3 uses portals with Octrees, they seems to be pretty popular now.