Not logged in, Join Here! or Log In Below:  
News Articles Search    

Submitted by Ville Miettinen, posted on March 26, 2001

Image Description, by Ville Miettinen

We've been pretty busy recently writing new demo material for Umbra, our visibility determination system for dynamic environments. Above are shots from two of the demos; the top row displaying an urban scene with 16,000 buildings and 4,000 moving cars (and a rather hacked traffic light system). The bottom row contains shots of Grand Canyon -- we wanted to see how well generic occlusion culling algorithms work with terrains. The terrain is by no means static; one can pick up pieces of it with a mouse and see how the changed geometry affects the visible set of the terrain.

More images, these and other demos, the new 500-page manual of the system, API headers etc. can all be downloaded from .


Image of the Day Gallery


Message Center / Reader Comments: ( To Participate in the Discussion, Join the Community )
Archive Notice: This thread is old and no longer active. It is here for reference purposes. This thread was created on an older version of the flipcode forums, before the site closed in 2005. Please keep that in mind as you view this thread, as many of the topics and opinions may be outdated.

March 26, 2001, 01:30 PM

Wow.... nothin' more to say...

well, maybe yes... hehe... Are the buildings auto generated? ;p
is the lower right one rendered or a photo of the original? j/k..
great work!


visit Rarebyte!

Florian Hoenig

March 26, 2001, 01:55 PM

Interesting that every post starts with "wow" or something like that.
hmm, the terrain looks ok. is it frame-coherent ?
what about that window, is it a texture or can you really see inside?


March 26, 2001, 02:08 PM

Can you tell us more about the visibility determination system and how it works?

Does it just do some fancy FOV tests to determine what's visible, or is there more to it? Does the geometry in the scene have to be ordered/structured in a certain way for the visibility stuff to work correctly?

If the Umbra code can do advanced occlussion culling, I would be very impressed. Ie. if you have just a few polygons that are taking up most of the screen will polygons hidden behind these "large" polygons be thrown out?

Sebastian Sylvan

March 26, 2001, 02:16 PM

Is that terrain just an arbitrary mesh? Can you just create a mesh in say 3DS and convert it to terrain or does it have to be a heightmap?

Do you do any LOD on it?

How do you handle occlusion? Is the VSD just simple frustrum culling or what?


March 26, 2001, 02:55 PM

While the Umbra-guys are not posting yet, let me answer a couple of questions ;)

You can't see inside the building afaik, or at least I haven't noticed it in the demo.

>Can you tell us more about the visibility determination system and
> how it works?

They are using a hybrid mix of a *lot* of vsd's;
frustum + portal-culling, several types of occlusion-maps, octtrees, scanline-algo's etc.

>If the Umbra code can do advanced occlussion culling

Umbra does *the* most advanced occlusion-culling you have *ever* witnessed in realtime.

I'm very impressed by umbra - not to say knocked of my feet.

I still think though it doesn't have that much advantages for games, as games are (yet..) very restricted in their use of 3d, so most of the time it's good enough to do just frustum- and portal-culling.

I definitely see the future of Umbra in large-scale visualizations and simulations - and probably games too, although only in a few years time.


March 26, 2001, 03:27 PM

Whilst reading the old 300+ page manual, I stumbled across just about every spatial subdivision, occlusion culling, visibility determination scheme known by man. It's a nice read, go ahead if you have the time.

The terrain looks really impressive, adaptive tessellation on a per-polygon basis, or so it seems. The urban scenes look very impressive size-wise. Very nice stuff.


March 26, 2001, 03:44 PM

Well, it's something I would call 'SUPER'

Timothy Barnes

March 26, 2001, 04:10 PM

I like your city thingy

Also, the reason all the IOTD has are positive comments is because everyone(just about) here follows the old saying of "If you can't say anything good, then don't say anything at all."


March 26, 2001, 04:15 PM

Nope, not true :)

It's just that we don't say things suck even when they do, except when someone's bragging about some code or capabilities and we don't think it's justified :)


March 26, 2001, 05:16 PM

this was my first wow post (my 2nd ;p). I've been reading IOTD for a long time now, decided it was time to comment it :o)


March 26, 2001, 07:10 PM

Ok. With umbra you can show a lot of geometry "on the screen". But how to store this kind of amount of geometry? I would be very interested to hear how you would store a city of that size where almost every building and car is different from another?) (it's quite easy to store one or two different buildings and cars and use instances but in real life there are no *totally* identical cars or buildings)

Still I'm impressed. I hope someone one day uses this tool to make truly dynamic environment for a good game.


March 27, 2001, 01:42 AM

Indeed very impressive...


March 27, 2001, 04:20 AM

Umbra has some advanced streaming technology that allows objects to remain unloaded (on disk) until they become visible. What you suggested, a city where every building and car is unique, is very possible with the help of this system. However, a 'unique' city would truly be an artists nightmare (can you imagine the amount of work involved?).

BTW: I don't work on Umbra or whatever, I just read the manual. I did run some demo's on my PC so I do know this stuff actually works.


March 27, 2001, 04:39 AM

Nice quality engine. Although 150k, 50k (or even 10K!) licence cost is a little steep when you consider that RenderWare starts from 600 (about $1000) and RenderWare already has full multi-platform support. You just select a different compile option in dev studio and out pops your ps2 version! I've also seen it running and it seems kick ass fast. OpenGL+DirectX rendering supported! It has lots of stuff. Well worth 600. (P.S. I don't work for RenderWare, I just quite like it).


March 27, 2001, 06:14 AM

QRock, umbra has nothing to do with a platform-independent rendering layer like Renderware.



March 27, 2001, 06:47 AM

This is like being show a screenshot of the latest blockbuster game and being asked "say something constructive"
There's very little I can ask about this system that wouldn't make me sound cynical, so please understand that isn't my intention.
What Im curious about with the complex LOD/Vis/Occlusion systems on display here, is how well will this thinking will scale onto nextgen T&L hardware? With CPU aside, won't the "massaging" of so much data soon reach a detrimental tradeoff, where it becomes many magnitudes faster to have an imperfect visibilty set?
Just my 2c... I'd love to hear some other developers thoughts on this.


March 27, 2001, 07:00 AM

I think it's very cool that some people think they can compare a polygon-output-system with a VSD-system :)

zed zeek

March 27, 2001, 07:06 AM

anyone got 50 grand to lend?

Marco Al

March 27, 2001, 07:50 AM

AFAICS Umbra doesnt promise to give a perfect visible set most of the time, unlike say Fluid studio's method (which in turn doesnt promise much for dynamic parts of the scene). Speaking of which, anyone have a chance to compare the two in practice? (or would that then be under NDA?)

Perfect visible sets are nice though, for shadow casting.

John van der Burg

March 27, 2001, 09:41 AM

Umbra simply kicks ass.
Have no other words for it :)


March 27, 2001, 09:57 AM

I wouldn't want a perfect set... as it would require culling on a polygon-level instead of primitive- / object-level - and most HW-accelerators don't like that :)

James Matthews

March 27, 2001, 09:59 AM

Wow, just downloaded the demo - very impressive. I really like the Scout demo - if you create 10 or 50K objects, you can fly through them and pretend you're the Millenium Falcon trying to blow up the Death Star :)

Seriously though, that is some really impressive work. All the demos were amazing and ran at great framerates with the exception of the reflections demo which ran at something like 1fps for me! (GeForce2 GTS AGP 32Mb, PIII-933, 256Mb RAM) I don't know what happened there.

The terrain demo is very neat, as is the urban one. Great work!

Hannu K.

March 27, 2001, 10:36 AM

I downloaded the demo and the city was amazing. The VIS systems seemed to be working really well. Of course it was a bit choppy when I went higher and could see almost the whole city with one glance (like in top right shot)...


March 27, 2001, 10:44 AM

Another boring IOTD..

Sadly this IOTD forum is turning into a way for people to get free advertisment for their commercial projects. I'm not really interested in seeing these impressive IOTD's unless the authors are going to talk and answer questions about the internals of their engine etc. I prefer to see things like that CSG stuff earlier.

IMO if you post an IOTD you are prepared to discuss it with fellow coders in details, else your just showing off :-)

Bring back the landscape pics :)))

So, yeah, thats why I think it sucks to see stuff like this on here

byeee =)


March 27, 2001, 10:47 AM

Well said that man!

This vis stuff is really very advanced and so cool that its just amazine. Sadly, its just being advertised and not explined.

Bunch of ARSE!

I may as well post a pic of Quake 3

Bruce Sutherland

March 27, 2001, 10:59 AM

I have to agree GCool..

When I saw the screenshot of Reason a while back, I was quite surprised. These guys are basically exploiting flipcode for free advertising!

As you say, perhaps it would be acceptable if the posters were willing to discuss their programs in detail. Personally, though I would prefer that this remain a forum for non-commercial projects.

Bruce Sutherland

March 27, 2001, 11:00 AM

I have to agree GCool..

When I saw the screenshot of Reason a while back, I was quite surprised. These guys are basically exploiting flipcode for free advertising!

As you say, perhaps it would be acceptable if the posters were willing to discuss their programs in detail. Personally, though I would prefer that this remain a forum for non-commercial projects.

Bruce Sutherland

March 27, 2001, 11:05 AM

Oops I'm sorry.

That was my first post, and I hit refresh. I'm suitably embarrassed already, please don't hurt me! Please remove this and the duplicate!

Alex J. Champandard

March 27, 2001, 11:43 AM

Lennart wrote:

> and probably games too, although only in a few years time.

Hmmm, i'm sceptical... i'd go even further! This will be integrated straight into the hardware and drivers. Your app will say "Here's the whole world divided in chunk of polies, and the camera is here." and everything will be handled transparently. Just like manual texture management is becoming a thing of the past (virtual texture memory, mmmm :)

To that extent, i think Umbra is a bit of a waste of time for game developers... maybe an option for high end modelling packages (hence the price 8]

My 2p.

Hannu K.

March 27, 2001, 11:49 AM

Odd.. I have Geforce DDR, less memory & slower processor but the reflection demo ran smoothly with the default settings.

This thread contains 46 messages.
First Previous ( To view more messages, select a page: 0 1 ... out of 1) Next Last
Hosting by Solid Eight Studios, maker of PhotoTangler Collage Maker.