Doom3world

Hey everybody. It's been a loooong time since we've peeped a word to anyone. The team has undergone a lot of chaotic Real Life changes over the last year.

Our primary contributing 3D artists and myself have each gotten positions at commercial game companies. Our art director/manager has left to focus on building her portfolio in other areas (currently interning on a Hollywood movie by a rather famous director), and Paul, the lone wolf engineer and co-designer, started his graduate studies in AI. It's been a very exciting time for everyone and I'm immensely proud of the opportunity we've had to work together, although it's taken its toll on Ground Zero's progress. However, we are still very much committed to seeing this thing through and want to give a little sneak peak at some tech we've been working on for our next public prototype.


So, Paul found a method of very quickly spawning and rendering simple foliage objects. These objects cannot be lit (must use "blend blend" or similar) and are non-interactive once spawned, but can still be dynamically generated and are ideal for things like dense, non-colliding grass. As long as they all use the same texture sheet, it can pretty much be rendered with a few draw calls. The user can define the groundcover draw distance.


We use greyscale "watermaps" to help model the appearance of plantlife. A combination of local water availability and terrain elevation determines the type and density of foliage appearing. It really isn't demonstrated adequately here due to the limited variety of assets we have. Below are some images that demonstrate the watermaps more directly.


A couple other improvements Paul has made to the terrain generation includes performing vertex coloring based on slope to blend between materials (rock and sand here), and an optimization process that simplifies the mesh where there is little or no change in elevation.


I'll use this debug image to demonstrate height and water maps


Pretty obvious here. This began as 400x400 mesh but much of that is trimmed out. Our implementation can take an image of any resolution and map it to a mesh with user-defined max density.


Here we see where flat and gradually sloping areas can be simplified without loss in quality to reduce triangle count. This still has some significant bugs (a tendency to create "steppes" in borderline areas) but helps quite a bit depending on the heightmap.



This demonstrates a change in how aggressively the terrain is simplified. This can in some cases reduce triangle count to half, a fourth, or more. Very bumpy heightmaps do not benefit as much of course.




This is a flat terrain with the same image instead applied as a water map. You can see that it largely affects density here, but each plant is defined with a range of ideal water and elevation values so we could potentially transition from desert scrub to lush jungle given enough assets.



And finally just one more wide angle shot of some rolling terrain that shows off the material blending and subtle geometry optimizations.


We are by the way generating each location from real-world elevation data. The player traverses the game world via a 2d world map divided into a grid of sectors. Each sector's terrain and hopefully foliage are linked to specific segments of satellite imagery to create the illusion of a gigantic persistent world. I spliced this image together from DEM data, the full size is about 20,000x10,000 pixels.


...and although it can't hold a candle to what those crazy guys at Introversion are doing, this last image shows the same test image above applied as a population map. Street sections are laid down to connect population centers. This is solid pavement but will soon be proper blocks of buildings linked by streets (we've shown a bit of that capability in our youtube video preview from last winter).

That is just amazing, great work !
No wonder you guys got hired .

So much more than great...
What you achieved here is a masterpiece, really.

Can your tech can be coupled with the megatexture's one?

Awesome.

I honestly thought the first two shots were example shots of what you wanted, not in game renders.

Good lord!! You guys are taking the idTech4 engine to its limits already!!

Did i already said Awesome?

Simulating nature. That is really very impressive. So if you have an oasis with actual water, you would have bigger plants?

That's very very impressive.



Good works guys.

Wow, thanks everyone!

Smurk: That's just the idea. We could have a desert environment and give palm trees and stuff a high ideal water, paint an "oasis" on the water map, and they would be likely to appear as a little island of flora in that spot.

It's too bad that (as far as we've found) we can only blend two textures on the ground, otherwise we would have some grassy textures to enhance the water availability effect (it can look a little odd at the moment to have rich vegetation over bare rock and dry dirt). We can however base what material the terrain uses based on region, but we wanted to do some decent looking desert-ish areas first. Another addition that would help is to at the very least add a water plane so that rivers and ponds can appear if the elevation dips low enough, though that gets a little difficult as you can obviously have bodies of water appear above "0".

Eventually both bodies of water and roads would be best done as generated geometry that can be more arbitrary in shape, rather than awkward pre-made meshes that intersect and lock together (though Deavile will likely hire someone to kill me for saying so )

We are by the way always looking for similarly nutzoid programmers and artists interested in working with us. We have Subversion repositories set up for code, assets, and the unpacked mod itself, which are integrated with Trac. We also have access to a web-based scheduling and file sharing app through our host, and are rolling out a thorough design doc of all game systems to be implemented (we've gotten admittedly lazy with online documentation since it's been just a couple of us working mostly in person).

Specific coding tasks currently include (1) implementing a simple in-engine or external editor for some of GZ's tech (which would all be released in a form usable to the general D3 mod/mapping community), (2) fleshing out the procedural environment system, (3) building a simple 4X-style game system to handle inter-faction interactions, and (4) general gameplay features. Deavile is going to be focusing on developing an individual character social network model as a possible thesis project.

Those look fantastic!

looks top, keep it up...tis very shiny

That looks almost like a megatexture! Wow...you guys have outdone yourselves and any other mod I've seen so far

Glad to hear there's still progress going on, even though the game's old. You can bet you'll be getting a huge following if this keeps up

Just out of curiosity, does this still move at 1-3 FPS like the old tech demos did on a 3 ghz machine with Hyperthreading?

In all the screenshot cases above I was getting above 60 fps (the one reading 53 is an anomaly), with very exaggerated draw distances for the groundcover, and with multiple apps running in the background (blender, photoshop, etc). My system currently consists of a dual core Opteron @2.3GHz and an 8800 GT.

Of course these scenes don't include destructible vegetation and structures yet, but LODs are making this all very possible. We intend to provide the capability to increase scene complexity beyond anyone's own good, but it should scale well enough to lower systems. We have been keeping in mind that a remotely finished version won't be achieved for some time yet.

Out of curiosity, did you only get 1-3 fps on our most recent release (last christmas... wow time flies)? The demo before that was really horrible because of a batching problem, which has been largely overcome. We'd like to know if there are other significant performance issues.

Not sure but it was definitely a VERY early version that you guys put out. Looking forward to the new stuff!

Holy wow. IdTech 4 still impresses me to this day.

Excellent work!

Did you contact NMA and RPGCodex? They may be interested in GZ

I was just starting to say to myself that these reminded me of that Introversion project in the works. I better go check their blog and see what Chris Delay has been cookin' up. Looks fantastic btw. Real imagination using good 'ol Doom3.